Introduction

This document covers 3D printing concepts and principles, specifically using the Bambu Lab H2S. 3D printers like the H2S print layers on top of each other to form 3D objects. These layers are printed using different types of plastics, where the plastic is first melted and then extruded out of a nozzle.

Hardware

The H2S is enclosed on all sides in the shape of a rectangular prism. The inside of the prism is referred to as the chamber, which is climate controlled and contains all the machinery for 3D printing. _[src]

The subsections below detail the machinery within the chamber.

Toolhead

The machinery responsible for laying down material is the toolhead. _[src] The toolhead is an assembly consisting of ...

• a PTFE connector.

• a filament sensor: Sensor detecting the presence of filament in the toolhead, located where the filament is fed into the toolhead. The filament sensor prevents printing without filament, allowing prints to resume once new filament is available. _[src]

• an extruder: Motor within the toolhead that grips and moves filament between the PTFE connector to the hotend

• a hotend with nozzle: Assembly responsible for melting filament for deposit on to a print. A hotend includes a ...

  • coldend - keeps filament at lower temperature.
  • nozzle - heated to melt the filament and deposit it onto a print.

  A silicone sock fits over the nozzle, insulating it from the cooling from the part cooling fan.

  _[src]

• a part cooling fan: Fan located at the base of the toolhead. The part cooling fan directs air to the cooling ducts that sandwich the tip of the hotend's nozzle, rapidly cooling printed filament. _[src]

• a filament cutter: Upright arm on the toolhead's right face. The filament cutter gets pushed into the filament cutter stopper, which is an arm located on the right inside face near the rear (close to motor A just above the Y-axis linear rod), to push it into the filament thereby cutting it. The filament cutter stopper rotates out in position when cutting and rotates back to be stowed away afterwards. _{[src] [src]}

• a camera: Camera attached to the toolhead, used for calibrating motion accuracy and build plate recognition. _[src]

Filament enters the nozzle through the PTFE connector located at the top, where the extruder motor grabs it and pushes it into the hotend located at the bottom. The hotend's nozzle poking out of the toolhead enclosure is sandwiched between cooling ducts, where the part cooling fan directs air to rapidly cool filament as it's printed.

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Heatbed

As the name suggests, the heatbed is a heat controlled surface within the H2S. It magnetically secures a build plate, which is a swappable part that serves as the print surface (build plate types have different properties / target different filament materials). Depending on the material being printed, the heatbed's controlled heating may be required or otherwise beneficial for print quality (e.g., adhesion and / or reducing printing artifacts).

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Movement

The toolhead moves on the XY plane using the CoreXY system, H2S's system for moving the toolhead front-back and left-right. The system is comprised of a pair of synchronized motors at the rear face of the chamber responsible for moving the toolhead on the X and Y axes: A motor and B motor. The motors are located at the rear inside face of the H2S, near the top. The B motor is on the left and the A motor is on the right.

The motors connect through the X-axis linear rail and the Y-axis linear rods via a pair of belts. The ...

• X-axis linear rail is responsible for left-right toolhead movement.
• Y-axis linear rods is responsible for forward-backward toolhead movement (it moves the X-axis linear rail forward-backward).

Both motors work in tandem to coordinate movement in both directions (e.g., one motor isn't solely responsible on an axis).

The toolhead doesn't move on the Z-axis. Instead, depth is controlled by moving the heatbed down as layers are printed out from bottom-to-top. The Z-axis threaded and linear rods are responsible for moving the heatbed.

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Nozzle Cleaning

The H2S has 2 mechanisms to clean the nozzle. The first mechanism is the purge wiper, a block at the back left of the H2S responsible for cleaning the toolhead between prints / filament changes. The purge wiper consists of ...

• a nozzle wiper, which consists of a silicone waffle and strips.
• a purge chute, which is a chute leading to outside the chamber.

The toolhead knocks into the waffle / strips to clean off old stuck filament, sending it down the purge chute.

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The second mechanism is the nozzle wiper sheet, a sheet on the edge of the heatbed that the nozzle moves across to keep the tip smooth and free of debris. _[src]

Climate Control

In addition to the heatbed and the hotend, there are several additional climate control mechanisms within the H2S. These all work in tandem to appropriately heat and cool filament material:

• Chamber heat circulation fan: Heater located at the rear face of the H2S, used to increase the chamber's temperature. _{[src] [src]}
• Chamber exhaust fan: Fan located at the rear face of the H2S, exhausting air out of the chamber. The chamber exhaust fan may have a filter in front of it, referred to as the chamber filter, that partially filters air as it's exhausted out of the chamber. _[src]
• Chamber intake vent: Flap located at the top face of the H2S bordering the front, which opens to allow outside air in when the exhaust fan is running. _[src]
• Auxiliary part cooling fan: Fan on the left face of the H2S that provides additional cooling, supplementing the cooling from the part cooling fan. The auxiliary part cooling fan layers an airflow blanket over the freshly printed layer, supporting quick and even solidifying of the layer and thereby reducing the likelihood of deformations and / or poor layer adhesion. _[src]

Status Light

Just below the heatbed, facing forward and running side-to-side, is a light bar. The light bar, referred to as the status light, changes color to show the operating status of the H2S:

• White slow pulse (or off): Idle.
• Orange scroll: Print job preparing.
• White left-to-right fill: Print job progress.
• Red double flash: Print error.
• Green solid: Print successful. _[src]

Automatic Material System 2 Pro

Automatic Material System 2 Pro is an extension to the H2S that manages multiple filaments. The AMS 2 Pro ...

• enables multi-color and multi-material prints by swapping between filament spools during printing.
• automatically switches between filament spools if a filament spool runs out during printing.
• automatically identifies the color and type of filament spools (only for official Bambu Lab filaments, using RFID).
• dries filament spools (up to 65 celsius).

The AMS 2 Pro supports 4 spools per unit, and supports chaining up to 4 AMS 2 Pro units together to support up to 16 spools per print. Additionally, the 4 chained AMS 2 Pro units may be chained up even further by 8 AMS HT units, enabling up to 24 spools per print.

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Filament Inlet

The H2S's chamber has 2 inlets to feed filament to the toolhead, one specifically for TPU and one specifically for non-TPU. The non-TPU inlet passes filament through a filament buffer, a tension-control / slack-management device at the rear face of the H2S. The filament buffer slides forward and backward, storing a small buffer of filament as it slides forward.

When the non-TPU inlet is hooked up to ...

• an AMS 2 Pro unit, the unit's motor pushes filament into the filament buffer thereby storing a small buffer of filament. When the extruder consumes the filament in the filament buffer, the filament buffer slides backward. A sensor in the filament buffer feeds back to the AMS 2 Pro unit's motor to control filament feeding speed.
• the external spool holder is used, the buffer acts as an entanglement sensor. When the spool is tangled, the tension of the extruder pulling is detected by the filament buffer thereby cause the print to pause and the user to be prompted.

The TPU inlet bypasses the filament buffer. The inlet in positioned just to the right of the filament buffer, feeding the PTFE directly from the exterior into the chamber. The PTFE tube used for the TPU inlet may either be the same PTFE tube attaching the filament buffer to the toolhead (disconnecting it and reconnecting it to the TPU inlet) or a separate PTFE tube.

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Operation

The subsections below detail high-level operational guidelines of the H2S.

Operational Placement

The H2S must be placed on a flat and stable surface. The operating space recommended is 80cm width x 102cm depth x 105cm height, which covers the space required in the back for the exhaust and an AMS 2 Pro to sit on top. _[src]

Operational Climate

The H2S is recommended to be operated in temperatures between 15-30C (60-85F). If the temperature is ...

• < 15C, there may be issues with adhesion to the build plate and / or weaken layer bonding
• > 30C, filament may soften before reaching hotend, increasing risk of extruder or nozzle clogs.

The chamber has an assortment of fans and vents to circulate cool air / blow out hot air (e.g., chamber exhaust fan, auxiliary part cooling fan, and chamber intake vent), but in warmer climates that may not be enough. _[src]

Auto-calibration

H2S's auto-calibration attempts to adjust itself to account for the expected variances between manufactured H2S printers and variances caused by wear. Examples of calibrations include bed leveling (working around variances in the heatbed), motor noise cancellation, and vibration compensation.

Trigger auto-calibration manually by navigating to [Wrench Icon] → Settings → Calibration. Perform auto-calibration whenever ...

• there's a decrease in print quality.
• after printer maintenance.
• after firmware updates (recommended but not required). _[src]

Filament Loading

Filament can be loaded through either an AMS unit (e.g., AMS 2 Pro or AMS HT) or the external spool holder. The external spool holder is used when ...

• an AMS unit isn't attached to the H2S.
• the spool is oversized for the AMS unit.
• the spool is for a material the AMS unit doesn't support (but the H2S does).
• the spool is from an unsupported third-party. _[src]

To load filament using the AMS 2 Pro, ...

1. open the two tabs on the front edge and lift the cover.
2. stick the spool into one of the four slots, ensuring that it sits on the slot's roller and rotates freely.
3. push the slot's inlet release tab toward the spool and feed filament into that inlet - inlet will automatically grip and pull in filament.
4. close the cover and lock it in by closing the two tabs on the front edge.
5. select filament properties:
   • For Bambu Lab filament, filament color and material should be automatically detected (using RFID).
   • For filament not from Bambu Lab, navigate to [Spool Icon] → [Pencil Icon] (for the slot spool was added to) and select filament brand, material, and color.

To load filament using the external spool holder, ...

1. place filament on external spool holder, where filament tip faces up.
2. push filament through PTFE tube until you feel resistance (should reach into printer's extruder).
3. load filament into extruder:
   1. navigate to [Spool Icon] and ensure extruder icon is green (confirms filament reaches extruder).
   2. tap the external spool, then select filament brand, material, and color, then tap Confirm.
   3. tap Load (pulls filament into extruder).
4. inspect as loading process performs a sample extrusion:
   • Tap Filament Extruded, Continue if extrusion is thin, even, and steady line free from gaps and sputtering.
   • Tap Not Extruded Yet, Retry and gently push filament further into PTFE tube (to help extruder grip it) if extrusion doesn't happen, happens in blobs, or extrusion curls instead of dropping freely.

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Filament Refill

Most Bambu Lab filaments come wound up on twist-apart spools. Once the filament on the spool has been all used up, a refill may be purchased (refill means filament without a spool) and reinserted into the empty spool. Refills come pre-wound ready to be inserted directly on to the spool.

To refill a spool ...

1. twist-apart the spool.
2. place pre-wound refill over interior cylinder of spool, aligning refill's notch against the tiny square extrusion.
3. place two sides of spool back together and twist until it clicks.
4. remove plastic straps holding the refill's shape.
5. place sticker on outside of the spool.

Depending on the type of material, some filaments come wound up on cardboard spools. Only plastic Bambu Lab spools are refillable, not cardboard.

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User Interface

The H2S's UI is exposed via a touch screen on the exterior of the front face, located on the top left.

Along the left side of the UI are 5 options, each represented by an icon:

1. [Home]: Primary functions and readings (e.g., triggering prints, sensor readings, WiFi status, and statistics).
2. [Controls]: Control panel for hardware settings (e.g., fan speed, nozzle and heatbed temperature, light, speed, and motion).
3. [Filaments]: Control panel for filament management (e.g., AMS 2 Pro functionality and manually selecting material and color).
4. [Settings]: Control panel for printer calibration as well as system and identity settings (e.g., account information, WiFi, firmware, and USB).
5. [Health Monitoring System]: Printer diagnostics. _[src]

The subsections below provide instructions on how to navigate to important parts of the UI.

Calibration

To calibrate the H2S, navigate to [Settings] → Calibration → Print Calibration, select the desired calibrations and hit Start. _[src]

Print

To print, navigate to [Home] → Print Files and select the drive and file to load. Two drives should be present:

• Internal: Files preloaded onto the H2S's internal memory.
• USB: Files on USB drive plugged into the H2S.

Once a file is chosen, select the appropriate Plate and Nozzle (H2S comes with "Textured PEI" plate and "0.4mm Standard" nozzle - these should be selected as defaults). Then, hit Next and select the filament to print with. Then, hit Print to begin printing. _[src]

Print Speed

To configure the printing speed, navigate to [Controls] → Speed and select either Silent, Standard (default), Sport, or Ludicrous. _[src]

Toolhead and Heatbed Movement

To perform movements of the toolhead (XY axis) and heatbed (Z axis), navigate to [Controls] → Motion and tap the adjustment buttons as necessary. _[src]

Extruder Movement

To perform ad hoc extrusion and retraction of filament, navigate to [Controls] → Nozzle & Extruder and use the up/down buttons under Extruder. _[src]

Nozzle Type

When the nozzle has been swapped, navigate to [Controls] → Nozzle & Extruder and select the nozzle's type under Nozzle. _[src]

Nozzle Temperature

To set the nozzle's temperature, navigate to [Controls] → Nozzle & Extruder and select the nozzle's temperature under Nozzle. _[src]

Heatbed Temperature

To set the heatbed's temperature, navigate to [Controls] → Heatbed and select the temperature. _[src]

Chamber Temperature

To set the chamber's temperature, navigate to [Controls] → Chamber and select the temperature. _[src]

Chamber Light

To turn the chamber's light on/off, navigate to [Controls] and toggle the Light switch. _[src]

Heating and Cooling

To configure the H2S's internal climate, navigate to [Controls] → Air Condition and select either Cooling or Heating. Individual parts that control the climate (e.g., fans, heaters, and exhausts) are listed and can be individually controlled. _[src]

When the mode is set to ...

• cooling, the chamber heat circulation fan remains off and the filter switch flap is positioned down. Cooling mode should be used for filaments that have low heat resistance (e.g. PLA and TPU).
• heating, the chamber heat circulation fan automatically turns on, the auxiliary part cooling fan remains off, and the filter switch flap is positioned up. Heating mode should be used for filaments with high heat resistance (e.g., ABS, ASA, PC, and PA). _[src]

Filament Type

To select which filaments are in the AMS 2 Pro and / or external spool holder, navigate to [Filament] and select the desired spool to input the type, color, and manufacturer of filament. Bambu Lab filaments come with RFID that allows the AMS 2 Pro to automatically identify material and color. _[src]

Filament Auto Refill

When a filament runs out, the H2S and attached AMS 2 Pro unit automatically swap to a second spool to continue printing, provided that second spool has the same brand, color, and material of the original spool being printed with. To enable auto refill, navigate to [Settings] → AMS Options and select AMS Auto-Refill. Then, navigate to [Filament], select the wrench icon, and select Auto Refill to view refill relationships. _[src].

Filament Drying

To dry filament, ensure the spool is loaded into the AMS 2 Pro and navigate to [Filament] and find the water droplet icon. Below the icon should be a humidity sensor reading. Select the water droplet icon and either ...

• manually enter a heat and duration
• select the type of filament (loads in optimal heat and duration presets for the filament selected)

..., then select Start. _[src]

Filament Guide

The following table summarizes key characteristics of filaments supported by the H2S (as of time of writing). The column(s) ...

• Name is the material's name. Each material may come in one of many modified forms: HF (High Flow) means the material has been modified for high speed printing _[src], CF (Carbon Fiber) means the material has been fortified with carbon fiber. _[src], and GF (Glass Fiber) means the material has been fortified with glass fiber. _[src]
• Stiffness and Impact Strength gives a user-friendly for those specific properties.
• Heat Deflection Temperature states the minimum temperature at which 0.45 MPa and 1.8 MPa of stress cause the material to bend by a small standardized amount (ISO 75 deflection threshold). It gives an idea of how much heat the material can withstand before deforming. _[src]
• Saturated Water Absorption Rate states the percent increase in weight from absorbed moisture under a standardized climate. It gives an idea of how moisture resistant the material is.
• Nozzle temperature, Heatbed temperature, and Chamber temperature collectively define the H2S's heating requirements to effectively print the material.
• Drying states the temperature and time needed to dry out a material. Filaments must be dry prior to printing, and some materials require drying temperatures that neither the AMS 2 Pro nor the AMS HT can reach.
• Resistance states the resistance properties of the material (e.g., flammability).

Build Plate Guide

A plate that sits on the heatbed and serves as the print surface. There are different types of build plates, each with different properties targeting different filament materials (4 as of time of writing):

• Cool Plate SuperTack Pro - Designed to reduce PLA and PETG print failures through better adhesion at lower heatbed temperatures.
• Textured PEI Plate - Designed with a slightly rough surface enabling better first layer adhesion and allowing for the print to self-release (some filament materials only).
• Smooth PEI Plate - Designed with a smooth surface. Unlike the Textured PEI Plate, the smoothness of this plate contributes Z-axis precision (no roughness).
• Engineering Plate - Designed as a universal build plate, compatible with all filament materials (but requires a layer of glue before printing).

The following table summarizes filament materials supported and material requirements for each build plate.

Of the build plates listed, the ...

• Cool Plate SuperTack Pro targets PLA and PETG, allowing those filament materials to be printed at cooler temperatures.
• Textured PEI Plate primarily targets PLA, PETG, and TPU, but can also work with other filament materials. It has a rough surface to better bind against the first layer (some materials only - other materials may require glue). Prints can pop off of it by allowing the build plate to cool and slightly bending it (some materials only - other materials may bind too tightly to the build plate to allow it to pop off, meaning you need to use glue and maybe a scraper).
• Smooth PEI Plate is similar to Textured PEI Plate but its surface is smooth, meaning the first layer isn't textured and the print's Z-axis is more precise. Unlike the Textured PEI Plate, the initial layer doesn't naturally grip to the build plate (glue required) and prints can't pop off of the build plate (scraper required).
• Engineering Plate primarily targets high temperature filament materials, but is resilient enough to be an all-purpose build plate (supporting any filament material).

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Bambu Studio

Bambu Studio is H2S's desktop software. It provides access to MakerWorld (a repository of printable objects), processes 3D models for printing by slicing them, and controls and gets feedback from the H2S. _[src] Bambu Studio works with many brands of 3D printers, not just Bambu Lab printers. _[src].

User Interface

Bambu Studio has 6 main screens (referred to as tabs), which can be navigated between using the top toolbar:

1. Home: Welcome screen, user manuals, opening projects, print history.
2. Prepare: Object/model placement, orientation, and manipulation.
3. Preview: Print instructions, information, and diagnostics.
4. Device: H2S interface and management.
5. Project: Informative fields describing project.
6. Calibration: H2S calibration.

Above the top toolbar is the main menu, packed to condensed space. Next to the packed main menu are a few quick access buttons: Save, undo, and redo. Regardless of which screen you're on, the top toolbar (and main menu and quick access buttons) should always be present.

The standard workflow is to plan out what and where things get printed on the Prepare screen, then review how the print will get sliced along with diagnostics on the Preview screen, then initiate the print.

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3D Viewport

Bambu Studio has a 3D viewport on both the Prepare screen and the Preview screen.

Bambu Studio's Prepare screen is for transforming models for print (e.g., orientation, scale, position, and color) as well as configuring print settings (e.g., layer height and infill density).

Prepare viewport controls:

Bambu Studio's Preview screen is for exploring slices. Each screen is partitioned into a 3D viewport and a left sidebar.

Preview viewport controls:

To the left of the 3D viewport is a sidebar.

The sidebar contains a ...

• Printer section that controls which printer to use and its configuration (e.g., build plate and nozzle).
• Project Filaments section that controls the filaments are available to the project. For example, a model within the project can be painted such that different areas of the model use different filaments, but those filaments have to be made available to the project first via this section.
• Process section that controls the hierarchy of entities within the project (e.g., models may be grouped together, referred to as an assembly). Each entity has properties to it that can be modified (e.g., parameters that control how the model prints).

Project Filaments

Bambu Studio has a section for defining which filaments are available to a project. The Project Filaments section is in the sidebar of the Prepare screen and the Preview screen.

Each filament is assigned an ID (e.g., 1, 2, ...). Objects and layers within the 3D viewport, rather than being assigned an exact filament, are instead assigned one of these IDs. The filament assigned to the ID number can be swapped to a different filament via the dropdown next to the ID, thereby automatically updating any areas of an object layer making use of that ID.

• To add a filament to the list of available filaments, use the plus button.
• To remove a filament from the list of available filament, either use the minus button or click on the ellipsis next to the filament dropdown and select Delete.
• To remove a filament and reassign its usages to another ID, click the ellipsis next to one of the filaments, navigate to Merge with, and select the ID to merge with.
• To synchronize the available filaments with those loaded into the attached AMS 2 Pro / AMS HT units, use the button immediately to the right of the minus button.
• To configure the list of filaments available for adding, use the cog button.

At the bottom is an Add Mixed Filament button. Mixed filaments is a mix of existing filaments printed in interleaved layers to achieve a new color via half-toning (e.g., alternating between 1 layer black and 1 layer white gives the impression that the printed object is gray). Mixed filaments are not recommended on the H2S because it's a single nozzle printer - excessive swapping between filaments causes a lot of waste. _{[src] [src]}

Print Parameters

Bambu Studio has a section for defining how models and model groupings (assemblies) are printed. The Process section is in the sidebar of the Prepare screen and the Preview screen.

The Process section can change scope using a toggle (section 1). The scope can either be global, or it can target a specific set of objects (e.g., a model, an assembly, or some combination of models/assemblies). If not scoped globally, an object hierarchy will be displayed directly below the toggle (section 3). The selections in the object hierarchy will reflect those in the 3D viewport and vice versa.

Below the object hierarchy is a hierarchy of parameters that control printing:

• Quality tab organizes fidelity parameters (e.g., layer height and how to treat seams).
• Strength tab organizes solidity/firmness parameters (e.g., infill style/percentage and wall thickness).
• Speed tab organizes print speed (e.g., how fast toolhead moves when printing overhangs).
• Support tab organizes support parameters (e.g., minimum angle for which supports are required).
• Others tab organizes parameters that don't fit in one of the other tabs.
• Frequent tab caches parameters that have recently been changed.

A full accounting of parameters is beyond the scope of this section. Individual parameters will be referenced / explained in subsequent sections as needed.

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Print Preview

Bambu Studio will slice the objects on the build plate whenever ...

• switching from Prepare screen to the Preview screen.
• hitting The Preview at the top-right, which should enable whenever a change is made.

The Preview screen is where the layers, nozzle paths (G-code printing instructions), and printing diagnostics are color-coded and displayed to the user. The screen is broken up into the following controls / panels:

1. Layer slider: Scrubber that navigates between layers, highlighting those layers in the 3D viewport.
2. Path slider: Scrubber that navigates the nozzle path of the layer, highlighting in the 3D viewport what actually gets printed as the toolhead / nozzle moves from beginning to end.
3. Layer range toggle: If toggled, the layer slider will have two handles identifying a range of layers to highlight. If not toggled, the layer slider will have only one handle, meaning it will target exactly 1 layer for highlighting.
4. 3D viewport: Visualized layers and paths.
5. Slice result: Dialog mapping of path colors to meaning. In the above example, the colors map to print speeds.
6. Color scheme: Remaps colors to different metrics / diagnostics. In the above example, the colors map to print speeds. But, if this were instead changed to Temperature, it would map colors to nozzle temperatures at each point in the path.

There are several color schemes available. A full accounting is outside the scope of this section.

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Project Persistence

Bambu Studio saves and loads project state as a 3MF file.

• Load project: In the main menu, navigate to File → Open Project....
• Save project: In the main menu, navigate to File → Save Project (or Save Project as...).

Alternatively, Bambu Studio's Home screen integrates MakerWorld. MakerWorld is an online repository of printable projects, openable as if opening a local project. _[src]

Object Importing

Import 3D objects into the project either via ...

• the main menu: File → Import → Import 3MF/STL/STEP/SVG/OBJ/AMF....
• the Prepare screen's toolbar's import button (button 1, keyboard shortcut Ctrl+I).

The file formats supported by the import function span both graphics formats (e.g., OBJ) and manufacturing formats (e.g., STL).

Alternatively, Bambu Studio's Home screen integrates MakerWorld. MakerWorld is an online repository of printable projects. MakerWorld projects can't be imported directly into the current Bambu Studio project. However, it is possible to open a MakerWorld project, save it as a 3MF file (or export as some other file format), and import that file into an existing project. _[src]

Object Placement

In the Prepare screen's 3D viewport, objects can be moved by either ...

• selecting objects, then left-clicking them and dragging.

• using the auto-arrange tool in Prepare screen's toolbar (button 4, keyboard shortcut A), which will arrange all objects regardless of which are selected.

  _[src]

• selecting objects, then hitting arrow keys for 10mm movement. _[src]

• selecting objects, then hitting Shift + arrow keys for 1mm movement. _[src]

• selecting objects, then using the move tool in the Prepare screen's toolbar (button 6, keyboard shortcut M), which will present both movement axis arms that can be left-click dragged and a pop-up with coordinates and common alignment and distribution options.

  

  

  The screenshot above has the following sections:

  1. Object coordinates: Controls and reflects the object's position. As the position fields are updated, the drop-down defines the anchor point from which the movement occurs:

     • World Coordinates anchors from the front-left of the build plate.
     • Object Coordinates anchors from the object's current position (it offsets the object).

  2. Distribution and alignment: Organizes the positions of a set of objects relative to each other and the build plate. The drop-down defines whether the distribution/alignment happens against ...

     • the selected objects, via Align selected.
     • the entire build plate, Align plate.

  3. Movement axis arms: Sets object's position via dragging arms. _[src]

Object Rotation

In the Prepare screen's 3D viewport, selected objects can be manually rotated by using the rotation tool in Prepare screen's toolbar (button 7, keyboard shortcut R), which will present rotational axis circles that can be left-click dragged and a pop-up with angles.

• Rotate (relative) offsets the existing rotation.
• Rotate (absolute) sets the rotation relative to the build plate.

Alternatively, an object may be rotated via ...

• the auto-orient tool in the Prepare screen's toolbar (button 3) automatically attempts to rotate in a suitable way for printing.
• the lay on face tool in the Prepare screen's toolbar (button 9, keyboard shortcut F) allows you to select a face on which to lay the object down on the build plate. _{[src] [src] [src]}

Object Scale

In the Prepare screen's 3D viewport, selected objects can be manually scaled by using the scale tool in Prepare screen's toolbar (button 8, keyboard shortcut S), which will present scale axis points that can be left-click dragged and a pop-up with scaling parameters.

The screenshot above has the following sections:

1. Coordinates - ?

2. Scale - Percentage scaled vs original size (X, Y, and Z).

   Size - Absolute size on an axis (X, Y, and Z).

3. uniform scale: If clicked, the other axes will maintain proportions by automatically scaling to be based on a single axis that was scaled. _[src]

Object Combining

In certain cases, two objects may need to combine into one for printing, such that they print as a single object vs two separate objects.

In the Prepare screen's 3D viewport, select two or more objects, then right-click to open the context menu and select Merge. Merged objects are placed under a single assembly.

Once objects are within a single assembly, they can be manually moved into each other and / or levitated off the build plate using the move tool (Prepare screen's toolbar button 6, keyboard shortcut M). If objects aren't merged but occupy the same space, slicing will print them as if they're distinct. That is, if two objects occupy the same space, the outer shell / wall of both objects will be drawn inside each other.

Alternatively, an object can be loaded and combined with an existing object at the same time. In the 3D viewport, right-click the existing object to open the context menu and navigate to Add Part → Load and select the new object to combine with in the file selection dialog. The objects will be combined in the same way (as an assembly).

Alternatively, two objects can be repositioned and reoriented such that they touch each other using the assembly tool (Prepare screen's toolbar button 12, keyboard shortcut Y). The assembly tool opens a pop-up used to target how and where the objects touch.

The assembly tool has two Mode options:

• Point and Point Assembly: Touches objects on specific points (e.g., vertex).

  Click on a point on the first object and click on point on the second object. The first point should highlight as cyan while the second face should highlight as purple, and sections 2 and 3 of the screenshot should update to indicate that a selection's been made. From there, XYZ coordinate fields should show up in the dialog. Set those fields to 0 to bring the points together.

• Face and Face Assembly: Touches objects on specific faces.

  Click on a face of the first object and click on a face of the second object. The first face should highlight as cyan while the second face should highlight as purple, and sections 2 and 3 of the screenshot should update to indicate that a selection's been made. From there, the ...

  • Parallel button will reorient the objects so the selected faces are parallel.
  • Center coincidence button will bring the selected faces together.
  • Flip by Face 2 checkbox will flip second object such that the face's normal vector goes in the opposite direction.

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Object Painting

In the Prepare screen's 3D viewport, selected objects can be painted by using the paint tool in Prepare screen's toolbar (button 13, keyboard shortcut N), which will present a pop-up with painting parameters / controls.

• Filament is the filament type to paint with.
• Tool is the painting tool to use when painting. Regardless of the tool, paint is always applied using the left mouse button.

The remaining fields change based on which painting tool is used. When the paint tool is ...

• circle and sphere use a circle and sphere respectively to paint on faces. Circle applies paint to intersecting areas of faces inside the circle, while sphere applies paint to the intersecting areas of faces inside the sphere (flat vs volume). Other than that, the two painting tools are essentially the same.

  The option ...

  • Pen size controls how large the circle is.
  • Section view temporarily cuts the object, exposing the interior and allowing painting of areas that may be obstructed. Note that the cut happens on the camera's viewing plane (e.g., if viewing from the front the front plane is used to cut, or if viewing from the top then the top view is used to cut).
  • Vertical will only allow painting to happen in a straight line vertically. Note that vertical means vertical on the camera's viewing plane.
  • Horizontal will only allow painting to happen in a straight line horizontally. Note that horizontal means horizontal on the camera's viewing plane.
  • View: Keep horizontal reorients the camera so that build plate is horizontal. A secondary slider Rotate horizontally rotates the camera around the object horizontally.

• triangle, paints the entirety of triangles that make up faces.

  The option ...

  • Section view is exactly the same circle/sphere's version of the option.

• height range, paints the entirety of a layer range.

  The option ...

  • Height range controls how many layers to paint at once.
  • Section view is exactly the same circle's version of the option.

• fill, paints everything connected based on a connection criteria.

  The option ...

  • Connected same color specifies that painting must continue to propagate outwards from the starting point until it reaches a color that's different than that of the starting point's original color.
  • Edge detection specifies that painting must continue until it hits an angle greater than the specified threshold in Smart fill angle.
  • Section view is exactly the same circle's version of the option.

• gap fill, fills in small gaps based on the color of neighboring faces. This is used to clean up edges that the fill tool couldn't reach into. Unlike the other tools above, this tool doesn't use the mouse. Instead, the Apply button is used to apply gap filling to the entire object.

  ⚠️NOTE️️️⚠️

  There's a Gap area slider here but I don't know definitively what it does and the documentation doesn't state it either.

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Object Supports

Areas of an object that are overhangs may require supports. Supports are temporary additions added under these parts to help keep them stable during printing (e.g., prevent sagging). Supports easily snap off once the print completes.

To have Bambu Studio automatically generate supports, enable the property Support → Enable support. Supports will only be visible in the Preview screen (the screen responsible for showing slices), not this screen (Prepare screen).

The anatomy of a support includes ...

• the type (e.g., tree vs normal), which defines the support's structural shape.
• interface layers, which are layers that touch the object being supported.
• base layers, which are layers that aren't interface layers.
• gaps, which control how close the support gets to the object.

The subsections below discuss each of the above items in more detail.

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Support Type

Supports come in two types: Normal and Tree.

Each type comes in either auto mode or manual mode. When the mode is ...

• auto, supports are automatically generated based on the support parameters (e.g., threshold angle) and the user can choose to include / exclude areas (e.g., via support painting).

  The areas targeted for supports are defined by ...

  • Threshold angle - Generate supports only for overhanging slopes below this angle (acute angle between build plate plane and face of overhang).
  • Support critical regions only - Generate supports only for those areas deemed critical.
  • Remove small overhangs - Ignore small overhangs, as they're assumed to not need supports.

• manual, the user is expected to specify areas of the object that need supports (e.g., via support painting).

The support's type defines the geometry generated:

• Normal support: Overhangs are projected directly down to the heatbed.

  Normal supports come in two styles:

  • Grid / Default: Support areas are normalized to expanded rectangles.
  • Snug: Support areas are tightly aligned to overhanging areas. is tightly aligned to overhanging areas.

• Tree support: Overhangs are sampled to a set of circles propagating down to the heatbed, weaving around obstacles and possibly enlarging to provide better strength.

  Tree supports come in many styles:

  • Tree Slim: Aggressively merge circles from different branches as it gets closer to the heatbed, resulting in less filament being used.
  • Tree Strong: Aggressively avoid merging circles from different branches as it gets closer to the heatbed, resulting in stronger supports.
  • Tree Organic: Aggressively merge circles from different branches as it gets closer to the heatbed, resulting in less filament being used (similar end result as slim, but different approach).
  • Tree Hybrid: Combination of tree and normal supports, selected based on criteria.
  • Default: Blends Tree Organic and Tree Hybrid, depending on object features.

Normal supports work best with large planar overhangs, giving better surface quality vs tree supports. Tree supports often give better results with complex objects where overhang are small and / ot not planar. When in doubt, use tree supports in hybrid style, because it will explicitly check for planar overhangs and those areas to generate normal supports while the remaining areas get tree supports. _[src]

Support Gaps

The gap between supports and the printed object defines how tightly the support adheres to the object vs how easily it can be ripped off the object. Gaps are controlled through properties under Support → Advanced:

• Top Z distance: Vertical gap between the top of the support and the overhanging area of the object being supported.
• Bottom Z distance: Vertical gap between the bottom of the support and the overhanging area of the object being supported.
• Support/object xy distance: Horizontal gap between the support and object.
• Support/object first layer gap: Horizontal gap between support and object on initial layer.

If these gaps are set too small, the support may be difficult to remove or even fuse to the object (unless using dedicated support material such as Support for PLA). If set too large, the overhanging surface may appear rough or sagging due to insufficient supports. For example, ...

• Top Z distance < 0.16mm for a 0.2mm layer height may result in fusing of and / or difficulty removing supports.
• Support/object xy distance < 0.35mm may result in difficulty removing supports and / or damaging object up walls during removal.

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Support Interface

Interface layers are support layers that touch the object, while the rest of the support body is referred to as the base. Bambu studio allows targeting specific materials for a support's base and interface. Navigate to the properties under Support → Filament for Supports. The property ...

• Support/raft base controls the filament to use for the support's base.
• Support/raft interface controls the filament to use for the support's interface.

Additionally, properties under Support → Advanced:

• Top interface layers controls the number of layers between the top of the support and the overhanging area of the object being supported.

  Too few layers (< 2) and the interface will be weak, making rougher overhangs but easier to remove supports. Too many layers (> 2) and the interface will be stronger and provide a cleaner surface on the overhang, but risks tightly bonding to the object being supported making it harder to remove.

• Top interface spacing controls the distance between printed lines within the top interface layers (lower spacing means higher density).

  The less spaced out the lines are, the more contact points there are with the interface and the overhang it's supporting. Less contact points means the support should be easier to remove, but it may reduce the hold on / quality of the overhang.

• Independent support layer height controls whether the layer height of supports are independent from the layer height of the printed object they're supporting.

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Support Painting

In certain cases, it's beneficial to manually specify which areas of the object to explicitly support and unsupport. Two mechanisms exist for this: painting and blockers/enforcers.

• Painting: In the Prepare screen's 3D viewport, select an object and click support painting in the Prepare screen's toolbar (button 16, keyboard shortcut L). Bambu Studio will open a pop-up and present an isolated view of the object where areas can be painted as include vs exclude.

  

  

  To paint, select a Tool type. The tools configuration options will show up directly underneath. Regardless of the tool type, ...

  • using the left mouse button on the object to paint where supports should exist (e.g., section 5 of the example screenshot above, painted blue).
  • using the right mouse button on the object to paint where supports shouldn't exist (e.g., section 6 of the example screenshot above, painted red).

  Chances are the viewport will need to move around during the painting process. To move the viewport rather than paint (e.g., move camera, rotate camera, and zoom camera), use the same viewport controls as normal with the exception that any mouse button presses required are not on the object to be painted.

  On overhangs only defines whether surfaces available for painting are limited to only those deemed as needing supports (e.g., as defined by Threshold angle).

• Blockers/Enforcers: By adding a secondary object and intersecting with the supported object, supports are explicitly added / removed from the intersecting portion. Right-click an object to get its context menu, and either navigate to Support blocker or Support enforcer. Regardless of which you choose, the same object options will display for both (e.g., load a custom model, preloaded cube, or preloaded cylinder,). If ...

  • Support blocker is chosen, the new object loads tinted red, and can be moved over areas of the supported object that need to have supports excluded. A support blocker removes supports from the intersected area.
  • Support enforcer is chosen, the new object loads tinted blue, and can be moved over areas of the supported object that need to have supports included. A support enforcer adds supports to the intersected area.

  

Where supports generate depends on type of supports being added (e.g. tree supports). If the type is set to ...

• an auto type, any automatically generated supports that would have ended up at red areas will be missing / any blue areas will have supports if ones weren't automatically generated. In the sliced example below, the high-up right face has supports running to it because that area was explicitly painted to include supports. The high-up front face was explicitly painted to exclude supports, but the automatic support generation wouldn't have generated supports for that area anyways (it would have been free of supports regardless).

• a manual type, only blue areas will have supports generated. In the sliced example below, the high-up right face has supports running to it because that area was explicitly painted to include supports. The high-up front face was explicitly painted to exclude supports, but given that this is a manual type there wouldn't be supports for that area anyways (it would have been free of supports regardless).

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Raft

A raft is a type of support that elevates an object off the build plate. Rafts are commonly used ...

• to elevate the print off the build plate, avoiding common issues with the initial layer (e.g., elephant foot not part of printed object, thicker initial layer not part of printed object, and uneven bottom surface on the printed object due to textured PEI build plate).
• for materials that are prone to warping off the build plate (e.g., ABS tendency to warp corners lifting them off build plate).

Navigate to the properties under Support → Raft. The property ...

• Raft layers controls the number of support layers used to lift the object off the build plate.
• Raft contact Z distance controls the gap between the top of the raft and the object (prevents tight bonding, such that raft can be broken off).

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Object Cutting

In certain cases, an object may either need to be cut (e.g., oversized for printer) or may benefit from being cut (e.g., minimize need for supports or make it easier to sand/paint/finish). Cut pieces are typically assembled and fused back together after printing (e.g., glue, pen welding, joinery).

In the Prepare screen's 3D viewport, an object can be cut by selecting it and clicking cut tool in the Prepare screen's toolbar (button 10, keyboard shortcut C), which will open a pop-up, present a cutting plane in the 3D viewport, and present cutting plane rotational axis and offset height controls in the 3D viewport.

The cutting tool has two modes, chosen using the Mode dropdown at the top of the pop-up:

• Planar cuts the object using a flat plane.

  2. Rotation reflects the 3D viewport's cutting plane rotational control.

  3. Movement / Height reflects the 3D viewport's cutting plane height control.

  4. Add connectors manipulates the cut final pieces to add joinery mechanisms, making them easier to reassemble.

     If clicked, the cut plane is highlighted in the viewport and a pop-up of joinery options is presented (e.g., plug, snap, and thread) along with parameters for each option (e.g., depth and size). Set the joinery options as desired and click on the cut plane to place the joinery. Most joinery options are self-explanatory.

     ⚠️NOTE️️️⚠️

     For the Plug type, if you're confused about frustum vs prizm: Frustum tapers the sides as it goes up (similar to a pyramid) while the prizm option keeps the sides straight.

     To flip between the two sides of the cut plane, click the Flip cut plane button.

     To force the joinery in the middle of the cut plane, select Middle of geometry before clicking.

  5. After cut defines how the cut pieces are treated:

     • Object A/B: Object is split into two, where the checkboxes define how each piece gets oriented on the build plate.
     • Cut to parts: Object is split into an assembly of 2 parts, where parts remain in place.

  

• Dovetail cuts the object using a a flat plane with a flared-out trapezoid indent, referred to as a dovetail. The two pieces are intended to slide into each other where the indent cutout is.

  2. Rotation reflects the 3D viewport's cutting plane rotational control.

  3. Movement / Height reflects the 3D viewport's cutting plane height control.

  4. Groove manipulates the indent in the cut plane.

     Most of the options are self-explanatory. Groove Angle controls size asymmetry between the two sides of the indent. Flap Angle controls the angle at which the indent's flaps fan out.

  5. After cut defines how the cut pieces are treated:

     • Object A/B: Object is split into two, where the checkboxes define how each piece gets oriented on the build plate.
     • Cut to parts: Object is split into an assembly of 2 parts, where parts remain in place.

  

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Object Set Operations

In the Prepare screen's 3D viewport, selected objects can have set operations applied (e.g., union, intersection, and subtraction) by using the mesh boolean tool in Prepare screen's toolbar (button 11, keyboard shortcut B), which present a pop-up with which which operations to apply.

The mesh boolean tool has 3 possible operations:

• Union: Creates a new model composed of all individual models together.
• Intersection: Creates a new model composed of only the overlapping parts between all models.
• Subtraction: Removes a chunk from a model, using other models as the cut-out stencil.

Regardless of which you pick, you can specify which of the selected models to apply the operation to. The resulting operation creates a single model with the chosen set operation applied (not an assembly of models, but a single model).

Given that the mesh boolean tool creates a single new model, the resulting single model typically doesn't encounter overlap issues during slicing. For example, if models aren't union'd but occupy the same space, slicing will print them as if they're distinct. That is, if two models occupy the same space, the outer shell / wall of both models will be drawn inside each other.

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Negative Parts

A negative part is an object that gets combined with an existing set of objects (same assembly), but it's purpose is to subtract areas of the existing objects. Any region of the existing objects that intersect with the negative part are cut out during slicing.

To add a negative part, right-click on an object to open the context-menu and navigate to Add negative part and select either a primitive or Load... to import a model. The negative part will be placed under an assembly along with the parts of the original object.

As shown in the screenshots above, negative parts appear slightly transparent when viewed in the Prepare screen and can be manipulated just like any other object. However, in the Preview screen, any region of the existing objects that intersect with the negative part are cut out during slicing.

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Modifier Parts

A modifier part is an object that gets combined with an existing set of models (same assembly), but it's purpose is to modify properties of specific areas of existing models. Any region of the existing models that intersect with the modifier part have the modifier part's properties applied.

To add a modifier part, right-click on an object to open the context-menu and navigate to Add modifier and select either a primitive or Load... to import a model. The modifier part will be placed under an assembly along with the parts of the original object.

As shown in the screenshots above, modifier parts appear gold when viewed in the Prepare screen and can be manipulated just like any other model. However, in the Preview screen, any region of the existing models that intersect with the modifier part have their properties changed to that of the modifier part (e.g., change filament color or apply fuzzy skin).

Common use cases for modifier parts include ...

• strengthening specific areas of an object by increasing infill density (e.g., head of a wrench has a high infill density while the body has low).
• turning off fuzzy skin on specific areas of an object (e.g., the eyes, tongue, and nose of a teddy bear - doesn't make sense for these area to be fuzzy).
• reducing print speed in specific areas of an object (e.g., top of a tall hing object or other problematic areas).

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Object Text

Text can be placed on an object, extruded from an object, indented on to an object, or placed as a standalone extruded object on its own.

To generate text as a standalone object, in the Prepare screen's 3D viewport, click the text shape tool in the Prepare screen's toolbar (button 14, keyboard shortcut T). Text will show up in the middle of the build plate on the 3D viewport along with a pop-up where the text and its settings (e.g., font parameters) can be changed.

All parameters in the pop-up should be self explanatory, with the exception of Angle. Angle is the rotation of the text, which reflects the rotation circle in the 3D viewport.

To place text on an object, in the Prepare screen's 3D viewport, select the object and then click the text shape tool in the Prepare screen's toolbar (button 14, keyboard shortcut T). Text will show up on the object along with a pop-up where the text, its settings (e.g., font parameters), and how its placed on the object can be changed.

The parameters are the same as the parameter before, except for Mode and Operation.

• Mode defines how the text interacts with the object:

  • Surround surface generates text that wraps the object's surface.
  • Surround+Horizontal generates text that wraps the object's surface, maintaining horizontal alignment (e.g., bottom of text will be equidistant to the build plate plane at all points).
  • Surround projection by character is similar to Surround surface but parts of the text that don't sit directly on the object are removed.
  • Not surround generates text tangent to the face the text is positioned on (does not wrap / surround the object's surface).

  ⚠️NOTE️️️⚠️

  At the very top of the example object below is the projection option. Note that the top of the text is cut off.

  

• Operation defines how the text is applied to the object:

  • Part embosses the text on the object.

    Use Embedded depth to sink the text into the object (e.g., 1-2mm) because just printing on the surface on the object might not be enough to securely adhere to the object. Embedding past the surface creates a tighter physical connection to hold the text in place.

    ⚠️NOTE️️️⚠️

    Too far out? You might have issues with overhangs_BO and supports.

  • Cut indents the text into the object.

    Use Embedded depth to sink the indent into the object.

  • Modifier doesn't change object's geometry, but modifies the printing parameters for the area of the object where the text overlaps (e.g., change color where text sits).

    Typically used for creating 2D text patterns that are perfectly flush with the object's surface (e.g., fuzzy skin or different filament).

  

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Object Iconography

An SVG outline can be placed on an object, extruded from an object, indented on to an object, or placed as a standalone extruded object on its own.

To generate a standalone SVG outline, right-click on to empty space (not on an object) to open the context-menu and navigate to Add Primitive → SVG. In the pop-up dialog that shows up, select an SVG file. The selected SVG will show up in the 3D viewport as slightly extruded (Z-scale to adjust the extrusion).

To place an SVG outline on an object, right-click on an object to open the context-menu and navigate to Add Primitive → SVG. In the pop-up dialog that shows up, select an SVG file. The selected SVG will show up in the 3D viewport as slightly extruded (Z-scale to adjust the extrusion). The SVG wil show up on the object along with a pop-up where and how the SVG placed on the object can be changed.

The majority of the parameters are self-explanatory.

• Operation defines how the text is applied to the object:

  • Join embosses the text on the object.

    Use Depth to sink the text into the object (e.g., 1-2mm) because just printing on the surface on the object might not be enough securely adhere to the object. Embedding past the surface creates a tighter physical connection to hold the text in place.

    ⚠️NOTE️️️⚠️

    Printing on the surface on the object might not be enough securely adhere to the object. Once the icon has been placed, it's added under an assembly along with the object. Select the icon and move it slightly into the object. Embedding past the surface into the actual object creates a tighter physical connection to hold the icon in place.

    ⚠️NOTE️️️⚠️

    Depth value too high? You might have issues with overhangs_BO and supports.

  • Cut indents the text into the object.

    Use Depth to sink the indent into the object.

  • Modifier doesn't change object's geometry, but modifies the printing parameters for the area of the object where the text overlaps (e.g., change color where text sits).

    Typically used for creating 2D text patterns that are perfectly flush with the object's surface (e.g., fuzzy skin or different filament).

• Use surface wraps the icon around the surface. If unchecked, the From surface and Rotation fields will be enabled.

• Size is is the size of the icon.

• Mirror buttons are helpers to flip the icon.

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Layer Height

Layer height is the height of each layer in the print. The thinner the layer, the less ridges are visible as the object is printed upwards (Z axis), meaning a smoother overall appearance.

To set the layer height globally, ensure no object is selected and navigate to the properties under Quality → Layer height:

• Layer height - Controls height of each layer, except for the initial layer.
• Initial layer height - Controls height of the initial layer. A thicker initial layer may help with the print better stick to the build plate.

In addition, there are presets available for choosing common layer heights. These presets typically also set other other options, such as printing speeds.

The initial layer height is recommended to be 50% of the nozzle's diameter. Subsequent layers are recommended to be between 20% to 70% of the nozzle's diameter. For example, if using the 0.4mm nozzle that comes with the H2S, the initial layer would be set to a layer height of 0.2mm and the remaining layers can be set to anywhere between 0.08mm to 0.28mm. This information is also available under the printer setting's Extruder section.

Variable Layer Height

In certain cases, it's more efficient for an object's layer height to be variable. For example, consider printing a half sphere. As the layers converge to the top of the half sphere, the slope gets more and more horizontal, leading to obvious stepping.

One way to mitigate stepping is to set the layer height to something very small (e.g., 0.08), but doing so is inefficient as the majority of the sphere doesn't have such a problematic slope. A more appropriate way to mitigate is to use the variable layer height tool. In the Prepare screen's 3D viewport, select an object and click the variable layer tool in the Prepare screen's toolbar (button 5), which will ...

• open a pop-up dialog.
• open a pop-up right panel.
• change the view of the object in the 3D viewport to show layers using oscillating gradients and colors.

The right panel pop-up represents the layer height of the object. As the mouse scans over it bottom to top, the corresponding object in the 3D viewport should highlight indicating what portion of the object the current mouse position controls. At any height in the right panel, ...

• left mouse press lowers the layer height at the highlighted layer range.
• right mouse press raises the layer height at the highlighted layer range.
• mouse scroll widens / tightens the highlighted layer range (highlights more / less).

The dialog pop-up provides functionality to algorithmically set / manipulate the variable layer height (as opposed to the manual setting happening above):

• Adaptive button sets layer heights based on the Quality / Speed slider (right side is for quality, left for speed).
• Smooth button readjusts layer heights to even out sharp transitions between layer height based on the Radius slider (larger radius means smoother curve).
• Keep min checkbox instructs smoothing to not smooth out (change) the minimum assigned layer height.

When applying variable layer heights, ...

• if you have two objects with different layer heights, prime towers can't be enabled.
• objects with variable layer heights are incompatible with organic tree supports.

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Line Width

Line width is the width of filament extruded by the nozzle during printing. To get the extruded filament to lay down either wider or thinner, the print speed changes and / or the rate at which filament is being pushed out changes (flow rate). For example, to print with a wider line width, the nozzle's head may print at the same speed but push out more filament. That is, the layer is being printed at a specific height and speed, but pushing out more filament at that layer height and speed causes that extra filament to get flattened by the nozzle's tip as it's being laid down, spreading to the desired line width.

To set the line width, navigate to the properties under Quality → Line width:

• Default - Line width override for any properties below that are set to 0 (e.g., if the Outer wall's value is 0, Default's value is used instead).
• First layer - Line width override for the initial layer, overriding all other properties below exclusively for the initial layer (e.g., First layer's value is used for outer wall instead of Outer wall's value when printing the initial layer). This value is typically larger than normal to provide better bed adhesion.
• Outer wall - Line width of outer walls.
• Inner wall - Line width of inner walls.
• Top surface - Line width of top surfaces (regions of the model where nothing else is printed on top).
• Sparse infill - Line width of sparse infills.
• Internal solid infill - Line width of internal solid infills (top shells just before the final top shell / bottom shells just after the initial bottom shell).
• Support - Line width of supports.

The line width is recommended to be 75% to 150% of the nozzle's diameter. Otherwise, the print quality will likely be poor. For example, if using the 0.4mm nozzle that comes with the H2S, the line width should be between 0.3mm and 0.6mm.

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Object Seam

A seam is a mark that shows up when the toolhead prints an enclosed path, showing up where the start and end of the path meet. The screenshot below highlights where seams will show up on an example object once printed.

There are several ways to control the appearance of seams: Algorithmic placement (e.g., hiding seams on edges), manual placement (e.g., seam painting), and specialized printing techniques (e.g., scarf seams). The subsections below detail the common methods to mitigate seams.

Algorithmic Seam Placement

Bambu Studio can algorithmically control the placement of seams in several ways. The easiest is through the Quality → Seam → Seam position parameter. The value ...

• Nearest positions seam on a vertex in attempt to hide it (suitable for objects with sharp angles), prioritizing concave non-overhand vertex, then convex non-overhand vertex, then any non-overhang vertex, then finally overhang vertex. If no suitable vertex is available, seam is placed near the previous layer's seam.
• Aligned positions seam near the previous layer's seam.
• Back positions seam in the back, where back is defined as the back of the build plate.
• Random randomly distributes the seam, potentially giving the print irregular dots /scratch-like marks.

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Seam Painting

Similar to object painting, the placement of a seam can be painted on to the object. In the Prepare screen's 3D viewport, select the object and paint a seam by using the seam paint tool in Prepare screen's toolbar (button 17, keyboard shortcut P), which will present a pop-up with painting parameters / controls.

Seam painting is operationally similar to normal object painting:

• Use the left mouse button to paint the areas where the seam should be forced.
• Use the right mouse button to paint the areas where the seam should be prohibited.

During slicing, the seam should show up in the areas painted forced / not show up in areas painted prohibited.

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Scarf Seam

A scarf seam is a specialized form of seam, intended to hide its appearance for objects that are round to the point where the seam can't be hidden (e.g., sphere, cylinder, or some round object that contains no natural edge for the seam to hide). At the ...

• beginning portion of the path, the amount of filament gradually increases as it lifts off (tapered).
• ending portion of the path, layer height gradually decreases as it comes to a stop (tapered).

The end result is the the start-stop region partially overlap vs a hard start-stop, blending in better.

-------------.  ,-----------
     end   ,' ,'
         ,' ,'
       ,' .'
     .' .'  
   .' .'   start
--'  '-------------

For scarf seams to be enabled, the filament being printed with must have scarf seams enabled in its filament settings: In the Prepare screen's sidebar, navigate to Project Filaments, then select the ellipsis for the desired filament and navigate to Filament → Filament scarf seam settings

• Scarf seam type: Must be set to either Contour or Contour and Hole for scarf seams to be enabled.
• Scarf start height: Height at which the nozzle starts printing the wall, specified in mm or percentage of layer height.
• Scarf slope gap: Scarf seam cuts into the inner wall to accommodate excess material, represented as a percentage of the nozzle diameter multiplied by some internal constant.
• Scarf length: Length of the seam. Disabled if set to 0 or the option Scarf around the entire wall is enabled in print parameters.

-------------.  ,-----------
     end   ,' ,'
         ,' ,'
       ,'  '
     .'    | 
   .'      | start
--'        '------------------

In the object's parameters, ...

• when Quality → Seam → Smart scarf seam application is ...

  • enabled, scarf seams are applied as needed. Specifically, when the layer wall isn't part of an overhang and doesn't have any hard edges for the seam to hide in, that's when scarf seams are applied.
  • disabled, scarf seams are applied to all areas.

  ⚠️NOTE️️️⚠️

  Why not on overhangs? Because scarf seams are too weak for overhanging areas?

• Quality → Seam → Scarf application angle threshold is the angle that is considered sharp enough for seams to hide in. Angles wider than this will enable scarf seams.

• Quality → Seam → Scarf around entire wall makes the entire wall a scarf seam.

  ⚠️NOTE️️️⚠️

  According to the source: Enabling this option requires caution as it may result in using a smaller extrusion amount for the entire perimeter, which may cause poor adhesion between lines and result in surface defects.

• Quality → Seam → Scarf steps is the number steps to print the scarf seam. That is, the toolhead prints the scarf seam as a series of incrementing steps rather than a raised slope. This value controls the number of steps.

  ⚠️NOTE️️️⚠️

  According to the source: ..., it should be noted that some seam positions cannot be accurately divided into the set number of steps, so the actual scarf steps ≥ the set scarf steps.

• when Quality → Seam → Seam joint for inner walls is enabled, inner walls will also have a scarf seam.

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Fuzzy Skin

Fuzzy skin is a rough texture targeting the outside wall of an object and potentially holes within that object (just the walls, top and bottom surfaces won't be textured). It does this by adding random jitters to wall paths during slicing. The purpose of fuzzy skin is two-fold: It's either aesthetic, or it's intended to make the printed object easier to grip, or both.

Fuzzy skin parameters are under Others → Special mode.

To enable/disable fuzzy skin set the property Fuzzy skin to either ...

• Contour, which targets just the outer walls on the outside perimeter.
• Contour and hole, which targets the outer walls on both the outside perimeter and the perimeters of any holes.
• All walls, which targets inner and outer walls on both the outside perimeter and the perimeters of any holes (jitters inner walls as well).
• None(allow paint), which targets specific walls on the object to make fuzzy via the fuzzy skin paint tool. See subsection on fuzzy skin painting.
• Disable, which disables fuzzy skin entirely.

If enabled, the parameter ...

• Fuzzy skin point distance controls the interval at which the jitter is updated. For example, setting it to 1mm produces smoother grooves vs 0.2mm because the toolhead's position is getting randomly offset every 1mm instead of 0.2mm.

• Fuzzy skin thickness controls the depth of the nozzle jitter, making the fuzziness more pointy. A value too high may cause overhang issues.

• Fuzzy skin generator mode controls how fuzzy skin is printed. A value of ...

  • Displacement jitters the toolhead's position out, creating a fuzziness but there'll likely be a gap between the fuzzed outer wall and inner walls / infill.
  • Extrusion jitters the toolhead's extrusion to be more/less (nozzle position stays un-jittered).
  • Combined combines both Displacement and Extrusion, with the intention that Displacement's gaps are filled with the extra filament extruded from Extrusion.

• Fuzzy skin noise type controls which algorithm is used to generate the noise that the toolhead's jittering is based off of.

• Apply fuzzy skin to first layer controls whether the first layer's walls should have fuzzy skin applied.

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Fuzzy Skin Painting

Rather than having walls be fuzzy skinned in their entirety, the object can have fuzzy skin painted on to particular areas such that only those painted areas print as fuzzy skin. In the Prepare screen's 3D viewport, select an object and click fuzzy skin painting in the Prepare screen's toolbar (button 19, keyboard shortcut H). Bambu Studio will open a pop-up and present an isolated view of the object where areas can be painted.

Tool options and controls are nearly exactly the same as those for normal object painting. Select a Tool type and the tools configuration options will show up directly underneath. Regardless of the tool type, ...

• use the left mouse button on the object to paint where fuzzy paint should exist.
• use the right mouse button on the object to paint where fuzzy paint should not exist (removes paint if it exists).

To move the viewport rather than paint (e.g., move camera, rotate camera, and zoom camera), use the same viewport controls as normal with the exception that any mouse button presses required are not on the object to be painted.

For painted fuzzy skin to be applied to the print, ensure Other → Special Mode → Fuzzy Skin is set to None(allow paint).

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Skirt

A skirt is one or more loops printed around the objects on the build plate, where there's a gap between the loops and the objects (not touching). The purpose of a skirt is to prime the nozzle. It's typically not required on the H2S because the nozzle already gets primed when a print starts by printing a small line, called a prime line.

Nevertheless, skirt loops can be enabled through the property Other → Bed Adhesion → Skirt loops and Skirt height. The example below has 4 loops set at a layer height of 2.

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Object Brims

A brim is several outer walls added around the bottom layer of a printed object, such that the object has a bottom similar to the brim of a top hat. Its purpose is to enhance bed adhesion of objects ...

• with a small base (e.g., a tall cylinder with a small radius).
• that are prone to warping at the bottom edges, lifting off the build plate as they warp (e.g., ABS is prone to this because it shrinks as it cools).

Brim parameters are under Other → Bed Adhesion.

The parameter ...

• Brim type defines how and what type of brim is applied. A value of ...

  • Auto lets Bambu Studio decide whether to add a brim and how wide it should be, taking into account the geometry and the properties of a filament being printed with.
  • No-brim forces no brims.
  • Outer brim only forces a brim on the outside perimeter.
  • Inner brim only forces a brim on the inside of the perimeter, assuming the object has a hole inside (being hollow inside doesn't count).
  • Outer and inner brim combines both the Outer brim only and Inner brim only options above.
  • Painted places points / stretches of brims, referred to as brim ears, at user-defined locations around the bottom of the object (locations that are likely to warp off the bed). See subsection on brim ears for how to place.

  🔍SEE ALSO🔍

  • Bambu Studio/Brims/Brim Ears

• Brim width defines the distance between the outer-most bring and the printed object (how wide the brim is).

• Brim-object gap defines the distance between the inner-most brim line and the printed object. A smaller gap typically improves the connection to the object while a larger gap makes pulling off easier.

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Brim Ears

A brim ear is a point / stretch of brim at user-defined locations around the bottom of an object. Similar to object painting, the placement of brim ears can be painted on to the object. In the Prepare screen's 3D viewport, select the object and paint brim ears by using the brim ear tool in Prepare screen's toolbar (button 18, keyboard shortcut E), which will present a pop-up with painting parameters / controls.

For brim ears to be printed, ensure Other → Bed Adhesion → Brim type is set to Painted. Otherwise, a warning will display at the bottom of the pop-up as shown in the example above.

To place brim ears manually, left-click around the base of the object. When a brim ear is placeable, a partially transparent brim ear will show under the mouse, notifying that a brim ear can be placed in that spot. The brim ear's size is controlled by the Head diameter parameter, which is the diameter of the brim ear in mm.

To place brim ears automatically, use the Aut-generate points button. Where brim ears get placed depends on ..

• Max angle, which controls how sharp the angle must be for a brim ear to be placed there (e.g., 90 degree will place brim ears at perpendicular points on the bottom).
• Detection radius, which controls how to many brim ears are placed along contours (smaller value results in more brim ears).

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Object Walls

The number of walls printed for an object (Z axis) is set through the parameter Strength → Walls → Wall loops. The more walls, the stronger the print is (presumably). It's recommended that for ...

• functional objects, 3 to 4 walls will enhance structural strength and durability.
• decorative objects, 2 walls are sufficient to save material and improve print efficiency.

The number of solid layers for the top of the object is set through the parameter Strength → Top/bottom shells → Top shell layers. The thickness of the top shell should approximately match the thickness of the walls. For example, if the thickness of 5 walls comes out to 5mm, then the number of top shell layers should approximately come out to 5mm as well.

Similarly to the top shell layers, the number of solid layers for the bottom of the object is set through the parameter Strength → Top/bottom shells → Bottom shell layers. It's recommended that the bottom shell have a minimum of 4 layers to ensure a sturdy and flat foundation.

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Object Infill

While the exterior of a printed object are walls / surfaces, the interior area of is printed as an infill pattern. An infill patterns is a pattern where the user controls how densely the pattern is printed, where higher densities are typically associated with greater strength / greater load bearing capacity.

Infill parameters are found under Strength → Sparse infill:

• Sparse infill density controls the density of the infill. Infill densities of ...

  • >= 30% are considered well suited for functional prints (load bearing).
  • ~15% are considered a good balance between print efficiency and strength.

• Sparse infill pattern is the infill pattern to use.

  Pattern	Target	Details
  Concentric	Aesthetic	Transparent visuals; weak horizontal strength
  Rectilinear	Speed	Fast, low material; low strength
  Grid	Speed	Fast; material buildup at intersections → nozzle scraping/collisions
  Line	Strength	Better basic structure
  Cube	Strength	Uniform X/Y/Z strength; lightweight/insulating
  Triangles	Strength	Strong shear resistance; bridging gaps → needs more top layers, flow issues at intersections
  Tri-hexagon	Strength	Excellent shear + tensile strength; reduces warping
  Gyroid	Strength / Speed	All-direction support; long slicing time, large G-code, vibration at high speed
  Honeycomb	Strength	High rigidity + impact resistance; more material, slower print + slicing
  Adaptive Cubic	Speed / Functional	Saves material; prevents top collapse
  Aligned Rectilinear	Speed	Efficient; anisotropic strength, top surface may fall
  3D Honeycomb	Strength	Better interlayer bonding; faster than honeycomb
  Hilbert Curve	Aesthetic / Strength	Smooth surface, uniform stress; slow print + slicing
  Archimedean Chords	Speed / Quality	Continuous path; avoids buildup
  Octagonal Spiral	Aesthetic	Decorative; weak strength, poor cohesion → deformation
  Supporting Cubic	Strength	Stable multi-directional strength
  Lightning	Speed	Minimal material; non-structural
  Cross Hatch	Speed	Faster; non-load-bearing
  Zig Zag	Speed	Continuous extrusion; low strength
  Cross Zag	Structural Control	Tunable intersections (rectilinear variant)
  Locked Zag	Hybrid	Balanced appearance + strength

  ⚠️NOTE️️️⚠️

  List above generated by ChatGPT as a quick lookup guide.

In addition to the standard infill, it's possible to specify infill patterns for the top and bottom surfaces using the parameters Strength → Top/bottom shells → Top surface pattern and Bottom surface pattern. The patterns available are more limits than the full roster of infill patterns.

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Failure Modes

The subsections below detail how to inspect and diagnose aspects of the print.

XY Hole and Contour Fit

Printed objects that require accurate fitting with other components (e.g., screws or other printed parts) sometimes don't fit they way they should because of variances introduced during printing. For holes and contours running running down the Z-axis, Bambu Studio provides calibration steps to compensate for these variances:

• Contour - The outer perimeter of the object as printed up the Z-axis (collective outer perimeters of the layers that make up the printed object). The example above is the object of a salad bowl. The shape of the unhollowed out bowl is the contour.

• Hole - The perimeter of a void/cavity within an object as printed up the Z-axis. The example above is the object of a salad bowl. The shape of the hollow/indent in bowl is considered a hole.

  An object may have multiple holes. Types of common holes include threaded holes for screws / bolts, drainage holes, and holes for connectors (e.g., dowels).

The process involves printing a test object and either using calipers or a standard screw to determine how far off the hole/contour is from its intended baseline. That value can then be inserted into an object's properties under Quality → Precision → X-Y hole compensation and X-Y contour compensation.

Hole / contour compensation may be needed because ...

• the seam throws off hole precisions.
• the filament material may shrink as it cools.
• the filament material may have absorbed moisture, causing inconsistent extrusion.
• first layer may have been squished (elephant foot), distorting holes in that layer.
• the hole may be too small to accurately print - holes with diameter close to the nozzle's size / holes below 1mm.
• the hole may be fine, but may need to be chamfered (tapered lead-in) to accommodate the fastener.
• flow dynamics may need to be tuned.

For full instructions along with what exactly to print / measure, see the source document.

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XY Hole and Contour Gap

On a layer, gaps below a certain threshold are merged during slicing. This threshold is controlled via the property under Quality → Precision → Slice gap closing radius. Any gap smaller than 2x this property's value is automatically closed during slicing (e.g., if set to 0.05mm, gaps smaller than 0.1mm are closed).

In the examples above, the first screenshot has Slice gap closing radius set to 0.13mm while the second screenshot has it set to 0.02mm.

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XY Hole and Contour Thinness

By default, slicing removes or distorts areas of a contour / hole where the shape is a thin stretch, pin extrusion, or sharply acute corner. That is, if there are two points on the shape's outline with a distance less than the line width, it wouldn't be able to reliably print and so the slicer attempts to work around the "thinness" by distorting or removing it. Real world examples where this might be encountered include models containing of fan blades, thin tubes, line art, and small text.

One workaround is to narrow the line width of the entire object being printed. However, a more appropriate and efficient workaround is to set the property Quality → Wall generator to → Arachne. Of the two options for Quality → Wall generator, ...

• Classic uses a fixed line width.
• Arachne dynamically changes line width as needed.

Arachne helps mitigate the thinness problem described above at the expense of more seams. That is, where as there's typically a single seam on an object, with Arachne there may be multiple seams. Arachne starts and stops rather than pushing out a continuous stream of filament, and so each start-stop results in a seam.

Once Arachne is enabled, the extra properties displayed in the screenshot above become present:

• Minimum wall width: Minimum line width, as a percentage of nozzle diameter.
• Minimum feature size: Minimum thinness to filter out during slicing, as a percentage of nozzle diameter.

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Z Aliasing

Objects with a contours / holes that curve on the Z-axis (e.g., sphere and donut) experience a type of artifacting called stair-stepping, where as the curve's slope aggressively becomes more and more horizontal, overtly visible steps appear between neighboring layers.

To mitigate stair-stepping, either ...

1. reduce the layer height for the entire object.
2. reduce the layer heights where stair-stepping becomes prevalent, using the variable layer height tool.
3. set Quality → Advanced → Only one wall on top surfaces to Not Applied to reduce visible layer lines near the top surface. When set to Not Applied, the number of walls on the top surface is the same as the number of wall loops set under Strength → Walls → Wall loops. Effectively, it's overwriting the parameter Wall loops for the top surface to be a single wall.

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Elephant Foot

An elephant foot is a phenomenon where the first layer of a print slightly splays out. This happens because the first layer sits on a heated build plate and doesn't appropriately cool, and so either through the non-cooling itself or through the non-cooling along with subsequent layers weighing down on it, causes the first layer to squish and splay.

Elephant foot compensation is an property, located under Process → Quality → Elephant foot compensation, that shrinks the first layer. Shrinking the first layer is intended to compensate for the splaying that happens.

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Flow Dynamics

Flow dynamics calibration compensates for lags in extrusion. These lags are a result of nozzle pressurization: When filament is extruded, it takes time for pressure in the nozzle to build up to a level where plastic flows consistently. When the toolhead ..

• accelerates, the lag can cause under-extrusions resulting in gaps and / or thin lines.
• decelerates, the lag can cause over-extrusions resulting in blobs and / or stringing.

Flow dynamics attempts to compensate for the problems above by preemptively adjusting filament flow. This compensation improves print quality, especially when printing complex shapes at higher printing speeds (e.g., cleaner corners and sharper details).

Flow dynamics calibration should be performed whenever ...

• a new filament from different brand in introduced.
• the nozzle is worn out (increased friction)
• the nozzle is replaced (manufacturing tolerances)
• a filament's maximum volumetric speed / print temperatures are changed in filament settings.

While some other Bambu Lab printers have automatic flow dynamics calibration (e.g., H2D), the H2S require manual calibration. The steps for manual flow dynamics calibration are as follows:

1. Ensure the filament is dry / fresh and the nozzle has no blockages.

   Filaments should always be dry when printing. Damp filaments will render the calibration results unsuitable for use with fresh filament.

2. Ensure build plate is of correct type and clean.

3. Navigate to the Calibration page, select Flow Dynamics in the sidebar, and then click the Manual Calibration button at the bottom of the main page. It should switch the page to a Flow Dynamics Calibration page with input fields.

4. On the Flow Dynamics Calibration page, select the appropriate options and parameters, then click Calibrate. Printing of a test pattern should start once Calibrate is clicked.

   • Choose the installed nozzle diameter, build plate, and filament for calibration.

     • Smooth PEI build plate is recommended (Textured PEI build plate is usable as well).
     • Nozzle must not be worn out.
     • Nozzle must not have blockages.
     • Filament must not be of a soft / flexible material. Flexible filament materials, such as TPU, have a high chance of calibration failure.

     ⚠️NOTE️️️⚠️

     What happens if I want to calibrate for a soft material?

     What happens if I'm using a filament material that's not suited for Smooth PEI build plate or Textured PEI build plate? Why can't I use an engineering plate so that I can target any material?

   • Set Method to Pattern.

   • Set From k Value / To k Value to 0 to 0.05

   • Set Value step to 0.002.

5. Once the test pattern has finished printing, visually inspect and find the number corresponding to the cleanest printed corner.

   There should be numbers running down the right-hand side and 90 degree corners which those numbers correspond to on the left-hand side. Find the number with the cleanest / sharpest corner, where the corner has the least bulging or fraying.

6. On the Flow Dynamics Calibration page, click Next. It should switch to page asking for Factor K. Input the found number from the previous step and click Finish.

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Flow Ratio

Flow ratio is a scaling factor that adjusts the actual amount of filament extruded vs the theoretical amount calculated by the slicer. The flow ratio helps mitigate problems with over-extrusion and under-extrusion.

While some other Bambu Lab printers have automatic flow ratio calibration (e.g., X1), the H2S require manual calibration. The steps for manual flow dynamics calibration are as follows:

1. Ensure the filament is dry / fresh and the nozzle has no blockages.

   Filaments should always be dry when printing. Damp filaments will render the calibration results unsuitable for use with fresh filament.

2. Ensure build plate is of correct type and clean.

3. Navigate to the Calibration page, select Flow Rate in the sidebar, and then click the Manual Calibration button at the bottom of the main page. It should switch the page to a Flow Rate page with input fields.

4. On the Flow Rate Calibration page, select the appropriate options and parameters, then click Calibrate. Printing of a test pattern should start once Calibrate is clicked.

   • Choose the installed nozzle diameter and build plate, and filament for calibration.

     • Smooth PEI build plate is recommended (easier to observe flatness because it's not textured).
     • Nozzle must not be worn out.
     • Nozzle must not have blockages.
     • Filament must not be of a soft / flexible material. Flexible filament materials, such as TPU, have a high chance of calibration failure.

     ⚠️NOTE️️️⚠️

     What happens if I'm using a filament material that's not suited for Smooth PEI build plate or Textured PEI build plate? Why can't I use an engineering plate so that I can target any material?

   • Set Calibration Type to Complete Calibration.

5. Once the test pattern has finished printing, visually inspect and find the number corresponding to the smoothest surface.

   There should be numbers on each tab printed. View under side lighting and find the number with the cleanest surface, where there is no bulging or indents.

   

   ⚠️NOTE️️️⚠️

   The pictures above are from the Bambu Lab wiki, and they show that 5 is actually better than 0. That's why they're recommending a side lighting? So the indents / bulges are more visible.

6. On the Flow Rate Calibration page, click Next. It should switch to page asking for the number with the smoothest top. Input the found number from the previous step and click Calibrate. Printing of a second test pattern should start once Calibrate is clicked.

7. Once the test pattern has finished printing, visually inspect and find the number corresponding to the smoothest surface.

   There should be numbers on each tab printed. View under side lighting and find the number with the cleanest surface, where there is no bulging or indents.

   

8. On the Flow Rate Calibration page, click Next. It should switch to page asking for the number with the smoothest top. Input the found number from the previous step and click Finish.

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Slicer Diagnostics

The slicer output shown in the Preview Screen helps identify problems prior to printing.

Of the Color schemes available, the following ones help highlight problems:

• Line Type - Designates the path color based on print feature (e.g., infill, support, top surface, bridge, or overhang).
• Filament - Designates the path color based on which filament is being printed. The slice result will also show how much of which filament is consumed.
• Print Speed - Designates the path color based on how fast it prints.
• Fan Speed - Designates the path color based on how fast the part cooling fan is spinning.
• Flow Rate - Designates the path color based on how much filament is being extruded.

These color schemes can help diagnose issues before printing:

• Switch Color scheme to Line Type - Any overhanging areas missing supports?
• Switch Color scheme to Fan Speed - Any unsupported bridges / overhangs have inadequate cooling? Such regions must be printed slowly and heavily cooled so that it quickly hardens and prevents sagging.
• Switch Color scheme to Print Speed - Any speed increases in bridges / overhangs print excessively fast? Such regions must be printed slowly and heavily cooled so that it quickly hardens and prevents sagging. Generally, there shouldn't be any jarring shifts between speeds (unless overhangs or bridges). It all should blend and transition nicely.

For more information, see the source.

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FreeCAD

FreeCAD is a parametric 3D computer-aided design / modeling tool. It contains different segments of functionality, referred to as workbenches. Each workbench targets a different aspect of the overall design workflow (e.g., sketching, turning sketches into 3D objects, and assembling 3D objects together).

The following subsections give a basic overview and usage reference for the subset of workbenches related to 3D printing.

User Interface Layout

Regardless of which workbench you're in, FreeCAD's UI will likely have the sections highlighted in the screenshot above. Almost everything in the toolbar can also be accessed via the main menu and triggered via a keyboard shortcut.

Viewport

• (6) Viewport: The space in which work in performed. The viewport typically renders and allows control of geometry (e.g., 3D primitives, 2D sketches, and technical drawings). For some workbenches, the viewport displays something different than geometry (e.g., spreadsheet).

• (11) Navigation cube: When working in 3D, there will be a navigation cube (located in the viewport's top right in the example) that reduces the burden rotating and reorienting viewing angles, as well as changing perspectives. Clicking the various faces of the cube as well as the surrounding icons reorient the camera and change perspective.

• (12) Axis orientation: When working in 3D, the basis axes will be displayed from the current camera's orientation (located in the viewport's button right in the example).

• (10) 3D viewport boundaries / spatial unit selection: When the viewport is viewing geometry, this dropdown can be used to change the units of measurement used (e.g., metric to imperial). It also displays the bounds of the viewport in those units of measurement.

• (9) 3D viewport mouse controls: When working in 3D, the mouse controls can be changed to different presets using this dropdown (e.g., Blender style mouse controls vs mouse controls optimized for a trackpad).

  Hovering over the dropdown displays how mouse controls for the currently selected configuration (e.g., what right-click does).

• (3) 3D viewport helpers: When working in 3D, these toolbar buttons provide quick tools to adjust and reorient the view. From left-to-right, ...

  • zoom viewport in to all geometry.
  • zoom viewport in to selected geometry.
  • drop-down to reorient viewing angle and change perspective (e.g., orthographic vs perspective), providing similar to the navigation cube in the viewport.
  • reorient camera to point facing the selection (e.g., point towards face using face's normal vector).
  • drop-down to change how viewport shades models.
  • drop-down to filter mouse selections to only target specific types of 3D entity (e.g., point vs edge vs face)
  • drop-down providing access to various selection helpers (e.g., change how panels synchronize when something's selected)
  • launch measurement tool (e.g., measure area of selected faces or measure distance between two points).

Document hierarchy / operations

• (4) Model pane: List of open documents, as well as the hierarchy of each open document. In the example, the document Test3 has a part design body with a sketch in it.

• (5) Properties pane: For the selected items, this pane lists the properties for those items. If the item is selected within a 3D viewport, the Data tab below shows the physical properties (e.g., what it is) while the View tab below shows the visual properties (e.g., how its rendered).

  Note that properties are not limited to what's selected in the viewport. When an item in the model pane is selected, it has its properties show up.

• (7) Workspace tabs: Tabs to switch between workspaces.

Basic operations

• (1) Basic commands: These toolbar buttons give quick access to common operations. From left-to-right, ...

  • new document.
  • open document.
  • save document.
  • undo drop-down, which lists and allows going back to previous state.
  • redo drop-down, which lists and allows going forward to subsequent state after an undo.
  • recompute, which recomputes calculations for the current selection or the active document if nothing is selected within it.

• (2) Workbench switcher: Drop-down that switches between workbenches.

• (8) Diagnostic messages: Pop-out that displays log messages. The number displayed is the number of unread diagnostics messages.

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Spreadsheet Workbench

FreeCAD has a built-in spreadsheet and expression engine, accessible through the spreadsheet workbench. A spreadsheet is typically used to store parameters and run formulas, which then go on to be used as the parameters of geometry and other properties of an object. It can also go the other way, pulling data out of a model into a spreadsheet.

User Interface

Basic operations

• (1) Basic commands: These toolbar buttons give quick access to common operations. From left-to-right, ...

  • new spreadsheet.
  • import CSV as new spreadsheet.
  • export spreadsheet to CSV.

Viewport

• (10) Spreadsheet: A matrix of cells, identified by column letter and row number (e.g., C3).

  Type while a cell is selected to set that cell's contents. Right click on a row/column to add or remove rows/columns.

• (9) Cell alias textfield: This field shows and sets the alias for the selected cell, similar to pressing the cell alias button in the toolbar. When referencing a cell, the alias can be used as a friendly name.

• (8) Cell content: This field shows and sets the content of the cell, which may be a formula or a literal.

• (7) Zoom slider: This slider and accompanying drop-down are used to zoom in / out of the spreadsheet.

Cell operations and properties

• (2) Cell merge/split: These toolbar buttons merge and split cells. From left-to-right, ...

  • merge selected cells into a single cell.
  • split a merged cell back out to its original individual cells.

• (3) Text alignment: These toolbar buttons align text in a cell. From left-to-right, ...

  • align left.
  • align horizontal center.
  • align right.
  • align top.
  • align vertical center.
  • align bottom.

• (4) Text style: These toolbar buttons stylize the text in a cell. From left-to-right, ...

  • bold.
  • italic.
  • underline.

• (6) Cell colors: These toolbar buttons set the colors within a cell. From left-to-right, ...

  • text color.
  • background color.

• (5) Cell alias button: This toolbar option launches a dialog to set an alias for the selected cell. When referencing a cell, the alias can be used as a friendly name.

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Cell Types

A cell's contents may be ...

• a numeric literal: Identified when the cell contains nothing but a fractional
• a text literal: Identified by an apostrophe as the first character.
• an expression (formula): Identified by an equal sign as the first character.

As shown in the example above, formulas are unit-aware (e.g., a formula can add two angles together or two distances together). The cell displays the results in the user's desired unit system (e.g., imperial vs metric).

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Expressions

In addition to being set to literals, spreadsheet cells and other properties may also be set to expressions. An expression executes some piece of logic using basic operators, functions, constants, conditionals, and references to other properties (e.g., other cells or data within a model). Operators and functions are unit-aware, requiring a valid combinations of units if supplied. For example, 2mm + 4mm is valid while 2mm + 4 is not. This also applies to references to properties that have units (e.g., Pad001.Length + 1 isn't valid because it adds a pure number to a property containing a length - it requires Pad001.Length + 1mm).

Units

Numbers in an expression may optional have a unit. The following tables contain the unit designations recognized by FreeCAD when inserting a unit (e.g., 5 mm). The following tables were pulled directly from source.

Angle

Length

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Property Access

An expression can reference properties of other objects by referencing the path hierarchy. For example, if there's a diameter named (diameter constraint) lower_initial_diam within a sketch ...

• with the label my_sketch, it's accessible within the spreadsheet as =<<!!my_sketch!!>>.!!Constraints!!.lower_initial_diam.
• with the ID Sketch, it's accessible within the spreadsheet as =!!Sketch!!.!!Constraints!!.lower_initial_diam.

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Index Access

To reference an item in a list or tuple, use the [] operator. For example, !!Sketch!!.!!Constraints!![0] will pull the first constraint within the sketch object.

To reference an enumeration option's text, use the [] operator in addition to referencing the enumeration option itself. For example, Pad.Type.Enum[Pad.Type] will pull out the text for Pad.Type, while Pad.Type itself will only return it's index within the enumeration.

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Conditionals

Conditional expressions use C++ style ternary operator syntax: condition ? resultTrue : resultFalse. The condition is defined as an expression that evaluates to either 0 (false) or non-zero (true).

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Operators

Table pulled directly from source.

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Constants

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Functions

FreeCAD expressions support several built-in functions. The following sections each contain a subset of useful functions pulled directly from the source documentation.

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Trigonometry

Table pulled directly from source.

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Rounding

Table pulled directly from source.

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Boolean Logic

Table pulled directly from source.

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Statistics Operations

Table pulled directly from source.

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Object Creation

Table pulled directly from source.

matrix(
  a11; a12; a13; a14;
  a21; a22; a23; a24;
  a31; a32; a33; a34;
  a41; a42; a43; a44
)

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String Operations

Strings can also be created via string interpolation using the old Python % syntax for string formatting. For example, <<Cube length is %s and width is %s>> % tuple(Box.Length; Box.Width).

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Vector Operations

Matrix Operations

Rotation and Placement can each be represented by a Matrix. The following functions all take in a Matrix, Rotation, or Placement as their first parameter denoted in the table below by m. The type of the returned object is the same as the object supplied in the first argument except when using mtranslate on a Rotation, in which case a Placement will be returned.

Sketcher Workbench

Sketcher workbench allows creating 2D sketches. These 2D sketches typically go on to by used by other workbenches (e.g., they define the outline of some 3D feature in the creation of models via the part design workbench).

Sketcher workbench has the following core primitives:

• Element: 2D geometric primitive (e.g., point, line, arc, and spline)
• Constraint: Definition of an element's measurement, either directly (e.g., 5mm radius for an arc) or as a relationship (e.g., line 1's slope must be perpendicular to line 2's slope).

In the screenshot below, the red geometry are visualizations of constraints (e.g., angle and radius), while the white lines are the geometric primitives those red lines apply to (e.g., arc).

There are different element types (e.g., construction geometry, projection geometry) and different constraint types (e.g., reference constraints, driving constraints). These are documented in the subsections below.

User Interface

The Sketcher workbench has two modes: Editing a sketch or viewing a sketch. The toolbar buttons change depending on the mode. The UI layout shown in the screenshot above is when editing a sketch, which is the mode that users will spend most of their time in.

General Commands

• (1) General commands: These toolbar buttons give quick access to common operations. When not editing a sketch, the general commands are as follows:

  

  From left-to-right, ...

  • new sketch: Creates a new sketch object in the model pane.
  • edit sketch: Enters the currently select sketch object in the model pane.
  • attach sketch: Attach sketch to an piece of 3D geometry (e.g., face on a model).
  • reorient sketch: Attach sketch to an origin plane (e.g., XY plane).
  • validate sketch: Opens a pane to validate different aspects of the sketch (e.g., invalid constraints).
  • merge sketches: Merge the sketches selected in the model pane.
  • mirror sketch: Mirror the sketch selected in the model pane.

  When editing a sketch, the general commands are as follows:

  

  From left-to-right, ...

  • leave sketch: Stop editing sketch.
  • align view to sketch: Reorients camera such that it faces towards the sketch.
  • toggle section view: Temporarily cut through and hide geometry that occludes a sketch (e.g., when the camera is aligned to the sketch, it may be occluded by currently visible 3D objects).

• (13) Leave sketch.

Elements and Constraints

• (3) Construction geometry toggle.

• (2) Create elements: These toolbar buttons give quick access to create elements. From left-to-right, ...

  • create point.
  • create polyline.
  • create line.
  • create arcs of varying types and parameterizations (e.g., circular arc defined via 3 points, and circular arc defined via radius and angle, and elliptical arc).
  • create circle / ellipse using varying parameterizations (e.g., defined via 3 points, and defined via radius and angle)
  • create rectangles of varying types and parameterizations (e.g., rectangle defined via center and dimensions, e.g., rectangle define via top-left and bottom-right, and rounded rectangle).
  • create polygon with varying number of sides.
  • create slot of varying types.
  • create b-spline of varying types and parameterizations.

• (5) Constraints toggle: These toolbar buttons disable constraints or keep them enabled but render them unenforced (referred to as reference constraints).

• (4) Create constraints: These toolbar buttons give quick access to create constraints. From left-to-right, ...

  • create dimensional constraints of varying types (e.g., distance, radius, and angle)
  • create coincident constraint.
  • create parallel to basis axis constraint (e.g., force line to be horizontal or vertical).
  • create parallel constraint (e.g., lines 1 and 2 must be parallel).
  • create perpendicular constraint (e.g., lines 1 and 2 must be perpendicular).
  • create tangent constraint (e.g., line and endpoint of arc must be tangent).
  • create distance equality constraint (e.g., line 1 and 2 must be the same distance).
  • create symmetry constraint (e.g., points 1 and 2 must be symmetrical across line 1).
  • create block constraint.

• (7) Selection helpers: These toolbar buttons give quick access to select elements / constraints associated with the current selection. From left-to-right, ...

  • select constraints associated with selection.
  • select elements associated with selection.

• (8) Arc circular helper toggle: Toggles the visibility of the underlying circle / ellipse for circular arcs.

• (10) Internal geometry toggle: Toggles the visibility of the internal geometry for certain element types (e.g., ellipse arc).

• (11) Switch virtual space.

B-Splines

• (6) B-spline tools: These toolbar buttons give quick access to b-spline helpers and tools. From left-to-right, ...

  • geometry to b-spline.
  • increase b-spline degree.
  • decrease b-spline degree.
  • increase knot multiplicity.
  • decrease knot multiplicity.
  • insert knot.
  • join b-spline curves.

• (9) B-spline informational toggles: These toolbar buttons give quick access to toggle on/off information displayed for b-splines. From left-to-right, ...

  • b-spline degree visibility toggle.
  • b-spline control polygon visibility toggle.
  • b-spline curvature comb visibility toggle.
  • b-spline knot multiplicity visibility toggle.
  • b-splint control point weight visibility toggle.

Tools

• (12) Tools: These toolbar buttons give quick access to various sketching tools. From left-to-right, ...

  • fillet / chamfer.
  • trim, split, or extend edges.
  • project from external geometry (e.g., pull in an edge from an external model into the sketch) or project intersected external geometry (e.g., pull in an edge from a model face that intersects the sketch plane).

Panels

• (13) Constraints pane: This pane lists, allows selection, and allows configuration of constraints, mirroring whatever is selected in the viewport.

• (14) Elements pane: This pane lists, allows selection, and allows configuration of elements, mirroring whatever is selected in the viewport.

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Sketching

Sketching involves creating elements, constraining them, and deleting them. The sketch below is a non-trivial set of elements chained together using constraints.

The subsections below document these basic concepts.

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Creation

To create an element, select the element from the toolbar (or the main menu, or use the element's shortcut key) and click on the viewport multiple times. For most elements, on the first click the viewport should show that the item is being created, and the movement of the mouse button and subsequent clicks further constructs the element. For example, to add a line, select the line in the toolbar, click in the viewport, and slightly move the mouse. The line's preview will display.

A subsequent click will be complete adding the line.

In the preview, there are two textboxes, one that specifies a distance and one that specifies an angle. These are referred to as On-View-Parameters, and they're available for certain elements, When in preview, pressing Tab will cycle into these textboxes, where a value may be entered followed by pressing Enter. Using them adds constraints to line. For example, if used for the line above, a constraint is added for the line's length and another constraint is added for the line's angle from the horizontal axis.

Alternatively, an element can have constraints added to it by selecting the relevant portions of an element and clicking an applicable constraint. For example, the line can have the exact same constraints applied by ...

• selecting the line, then selecting distance dimension constraint in the toolbar.
• selecting the line and the horizontal access, then selecting the angle dimension constraint in the toolbar.

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Continue Mode

Continue mode allows element / constraint creation to continue after an element / constraint is created, allowing multiple such elements / constraints to be created many times over. The creation tool remains active until the user hits Esc or selects some other tool from the toolbar. For example, after selecting the line element from the toolbar and creating a line on the sketch, more lines can be created on the sketch without having to click the line element again in the toolbar.

Continue mode can be turned off in preferences (on by default).

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On-View-Parameters

For certain element creation tools, On-View-Parameters allows explicitly adding constraints during the creation process by presenting input fields alongside the element's preview. For example, dropping a line will show a textbox for length constraint and a textbox for angle constraint. Pressing tab cycles through these textboxes, while pressing enter adds the constraints.

Continue mode can be turned off and configured in preferences (on by default).

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Auto Constraints

When creating an element, if the placement of some part of that element ends on an existing element, an auto constraint may be applied. An auto constraint is a constraint that's automatically added by virtue of how the elements end up together. For example, if the end of a line ends up on the start of a line, auto constraint will add a constraint known as coincident constraint which bounds those two points together.

When an auto constraint is to be applied, the icon of the constraint is shown on the lower right of the icon of the element being created.

Auto constraints is enabled/disabled per sketch, not globally. To change, update in the constraints pane or the sketch's view Autoconstraints property.

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Selection

Elements and constraints can be selected in any of the following ways:

• Single selection: Left-clicking an element or constraint toggles whether its selected.

  Previously selected elements are not discarded on single select. While it isn't necessary to hold Ctrl while selecting multiple elements, it is beneficial in that a mis-click into empty space won't deselect everything.

• Box selection: Left-clicking an empty area and dragging draws a selection rectangle, selecting elements within the rectangle (not constraints, only selections). Depending on the direction of the drag, the selection behavior changes. If the box dragging is from ...

  • left to right, elements that lie completely inside the rectangle are selected.
  • right to left, elements that touch or cross the rectangle are selected.

  Previously selected elements are not discarded on box select.

• Connection selection: Double-clicking an edge selects all edges directly and indirectly connected to it via endpoints. Endpoints only need to have the same coordinates (no need endpoints to be connected via constraints - e.g.,coincident constraints).

  Previously selected elements are not discarded on connection select.

• Element / Constraints pane: Constraints and the individual components of each element (e.g., a line elements's endpoint and actual line) are selectable via the constraints pane and elements pane, respectively. The elements pane lists the elements component next to the element, which can be individually clicked (e.g., select 2-Line's first endpoint).

  

  Previously selected elements are discarded on connection select.

• Select all: To select everything within a sketch, use Ctrl+A or navigate to Edit → Select All.

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Deletion

To delete an element or constraint, select it and hit the Delete key. If an element is deleted, its related constraints are automatically deleted as well, even if they were left unselected when the Delete key was hit.

_{[[self src]](data:text/plain,This%20was%20derived%20using%20self%20experimentation%20-%20there%20is%20no%20source%20other%20than%20myself.)}

Constraint Expressions

Constraints can be named by either ...

• right-clicking on them in the Constraints pane and selecting Rename (shortcut key F2).
• double-clicking the constraint in the viewport and assigning a name, but this only works if the constraint accepts a value.

Constraints can also reference and calculate their values via expressions. The formula button (inside the value textbox, to its right) opens an Expression Editor window that allows entering an expression instead of a constant, similar to inserting a formula in a cell for a spreadsheet.

The expression can access data in the sketch (e.g., other constraints) as well as outside the sketch (e.g., alias in a spreadsheet or field in a VarSet). In the example, the constraint is copying the value of another constraint and multiplying it by 2.

_{[[self src]](data:text/plain,This%20was%20derived%20using%20self%20experimentation%20-%20there%20is%20no%20source%20other%20than%20myself.)}

Projection Geometry

An element is deemed projection geometry if that element was pulled in from a 3D object visible from the sketch. Projection geometry is linked to the 3D object it came from.

To project, select the External Projection toolbar button (keyboard shortcut G, X) and select until the all desired elements have been projected (Esc or select another tool to exit). In some cases, it may be difficult to select the desired external geometry (e.g., it may be on the opposite side of the object, hidden from view). Recall that the camera can be rotated while sketching. If rotated, the camera's rotation can be brought back inline with the sketch by clicking the Align View to Sketch toolbar button (keyboard shortcut Q, P): .

To project intersections with the sketching plane, select the External Intersection toolbar button (keyboard shortcut G, I) and select until all desired elements have been projected (Esc or select another tool to exist). In most cases, it's difficult to select the desired intersections because they're likely blocked from view. Recall that the Toggle Section View toolbar button (keyboard shortcut Q, S) will temporarily cut from view anything that extends past the sketch plane towards the camera: .

The color and line style changes based on the type of projected element and the state of the overall sketch. The screenshot below shows the default colors used by FreeCAD for the various types and states.

_{[src] [src] [src] [[self src]](data:text/plain,This%20was%20derived%20using%20self%20experimentation%20-%20there%20is%20no%20source%20other%20than%20myself.)}

Construction Geometry

An element is deemed as construction geometry if it isn't exposed to consumers of the sketch (it's internal to the sketch, hidden once the sketch is closed). Construction geometry is used within the sketch to assist in constraining other geometry.

Construction geometry comes in different forms:

• Construction geometry: A normal element in the sketch is construction geometry.

  

• Projected geometry that's also construction geometry: A projected element in the sketch is construction geometry.

  

• Internal alignment geometry: Construction geometry added by and tied to a complex element, used to control that element (e.g., ellipse control arms).

  

To toggle one or more elements to / from construction geometry, select the elements and click the toggle construction geometry button (keyboard shortcut G,N):

To toggle element creation from / to construction geometry, ensure nothing is selected and click te toggle construction geometry button. Toolbar buttons to create elements will change color to indicate that elements being created are construction geometry.

The color and line style changes based on the type of construction element and the state of the overall sketch. The screenshot below shows the default colors used by FreeCAD for the various types and states.

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Degrees of Freedom

If an element ...

• isn't constrained to the point where it's locked into a specific parameterization (e.g., location, rotation, angle, and whatever other parameters it may have), it's said to have n degrees of freedom, where n >= 1.
• is constrained to the point where it's locked into a specific parameterization, it's said to be fully constrained (0 degrees of freedom).

A degree of freedom is a parameterization that hasn't been set. For example, ...

• a point has 2 degrees of freedom:

  1. X position.
  2. Y position.

  The example below fully constrains a point by setting its position in relation to the origin of the sketch.

  

• a line has 4 degrees of freedom:

  1. Start point's X position.
  2. Start point's Y position.
  3. End point's X position.
  4. End point's Y position.

  The example below fully constrains a line by setting the position of its first point to the origin, and then giving it and angle and a length. The position of the second point is derived from the combination of angle and length.

  

• an arc has 5 degrees of freedom:

  1. Center point's X position.
  2. Center point's Y position.
  3. Radius/diameter of arc's underlying circle.
  4. Angle between the two points comprising the arc.
  5. What segment of the underlying circle the arc sits on.

  The example below fully constrains an arc by setting its center point to the origin of the sketch, setting the radius to 14mm, setting the angle of the arc to 45 degrees, and positioning the arc on the underlying circle by stating that the lower point sits 7mm above the X axis.

  

The overall constraint state for all elements in the sketch is shown in the Sketch Edit pane.

• Under-constrained / Fully constrained: When there's 1 or more degrees of freedom, the Sketch Edit pane will report that the sketch is under-constrained. When there's exactly 0 degrees of freedom, the Sketch Edit pane will report that the sketch is fully constrained. In the example below, the two lines each have a point with a coincident constraint to the origin while the other endpoint is unconstrained (4 degrees of freedom). Clicking the degrees of freedom text in the Sketch Edit pane will will select the two unconstrained endpoints.

  

• Redundant constraints / Partially redundant: If a sketch has constraints that deduce to the same thing, the Sketch Edit pane will report that the sketch has redundant constraints. In the example below, the line's start point has a coincident constraint to the origin and ...

  • the end point has a horizontal distance constraint and vertical distance constraint, both set to 1mm.
  • the line itself has a an angle constraint set to 45 degrees from the X axis.

  This reports a redundant constraint because the end point of (1mm, 1mm) implies a 45 degree angle from the X axis. Clicking the redundant constraints text in the Sketch Edit pane selects the redundant constraints.

  

• Over-constrained: If a sketch has conflicting constraints (they both can't be satisfied because they're opposed to each other), the Sketch Edit pane will report that the sketch has over-constrained. In the example below, the triangle in this sketch is constrained to be an equilateral triangle, but it also has a coincident constraint that says two of the triangle's vertices should be at the same point, making it an impossible to satisfy all constraints. Clicking the over-constrained text in the Sketch Edit pane selects the conflicting constraints.

  

  Typically, once a conflicting constraint is added, the number of conflicting constraints reported becomes much more than 2. That's usually because the 1 added constraint goes is invalid against many existing constraints. The Sketch Edit pane doesn't group conflicting constraints together (e.g., 1,3,5 are valid together vs 2,4 are valid together, but all together they conflict) or give any reasoning as to why the constraints conflict (e.g., deduced angle is 30 degrees but angle constraint is attempting to set to 45 degrees).

It is important that a completed sketch always be fully constrained, otherwise the solver (software responsible for applying constraints) may shift and reorient the elements on that sketch based on the what is and isn't constrained. Even if a sketch is fully constrained, it may still be subject to sketch flipping, a phenomenon where the sketch changes because even when fully constrained there is more than 1 possible outcome for the constraints. In the example below, both arcs have the exact same constraints (both fully constrained), but there are two possible solutions.

_{[src] [src] [src] [src] [src] [src] [[self src]](data:text/plain,This%20was%20derived%20using%20self%20experimentation%20-%20there%20is%20no%20source%20other%20than%20myself.)}

Sketch Flipping

Even if a sketch is fully constrained, it may still be subject to sketch flipping, a phenomenon where the sketch reshapes because even when fully constrained there is more than 1 possible outcome for the constraints.

• Example 1

  In the example below, both arcs have the exact same constraints (both fully constrained), but there are two possible solutions.

  

  Sketch flipping happens because, in certain cases, directionality may not exist. There's no constraint that ties the arc as to which side of the X axis it's on.

  This can be fixed by adding a constraint to force directionality. For example, adding a horizontal constraint between the end of the arc and the origin adds directionality. A horizontal constraint / vertical constraint is signed, meaning that a value of 12mm goes in one direction while -12mm goes in the opposite direction.

  

• Example 2

  In the example below, both shapes have the exact same constraints (both fully constrained) except that the second version is 50mm away from the Y axis instead of 16mm. Note that the sketch changed shape even though all other constraints are equivalent.

  

  As with the previous example, there is a lack of directionality that causes sketch flipping. The top horizontal line has a distance constraint of 10mm, but there's nothing constraining the order of the points (which of its two points is closer to the Y axis). The solver is free to swap the points as it sees fit, so long as the distance is still 10mm.

  Again, this can be fixed by adding a constraint to force directionality. For example, instead of using a distance constraint of 10mm, using a horizontal constraint of 10mm will. A horizontal constraint with a value of 10mm will fix the sketch into one orientation, while -10mm will fix it into the other orientation.

  

• Example 3

  The example below is similar to the previous example, except more complex. There's double flipping occurring:

  1. The box and triangle are flipping across the symmetry line
  2. The box has flipped such that the vertical line closer to the symmetry line has become the one farther from the symmetry line.

  

  Again, this can be fixed by adding one or more constraints to force directionality:

  • Add a horizontal constraint to the box to ensure its points don't flip.
  • Add a horizontal constraint between the symmetry line's point and either a point on the box or a point on the triangle, to ensure they stay on the correct side of the symmetry line.

  

To prevent flipping, it's important to anchor the sketch using constraints that support directionality. In general ...

• horizontal constraints are signed, so they can specify directionality.
• vertical constraints are signed, so they can specify directionality.
• angle constraints are signed, so they can specify directionality, but that only works if the angle is anchored to something fixed (e.g., angle from x-axis and not the angle for an arc).
• block constraints force an exact position, similar to adding a horizontal constraint and vertical constraint against the origin.

_{[src] [src] [[self src]](data:text/plain,This%20was%20derived%20using%20self%20experimentation%20-%20there%20is%20no%20source%20other%20than%20myself.)}

3D Feature Validity

For a sketch to be valid for use as a 3D feature (e.g., as a profile that extrudes into a 3D addition or punches into a 3D face), it must conform to several expectations:

• No open contours: A contours must be closed, meaning gaps between endpoints of that contour aren't allowed (no matter how small).

  

• No intersection: A contour must not intersect with other contours or self-intersect.

  

  ⚠️NOTE️️️⚠️

  While it contours can't intersect, one contour is allowed to be wholly contained in the. See further down for more information.

• No shared edges between contours: Two contours must not share an edge.

  

• No T-connections: A contour must not have two edges sharing a common point / point touching an edge.

  

Contours are allowed to be nested (but not intersecting). Nesting alternates between creating voids in the 3D feature.

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Elements

An element is a 2D geometric primitive (e.g., point, line, arc, and spline). The element itself defines a primitive, while the parameterization of the primitive are defined by constraints applied to the element (constraints are discussed in later sections).

The subsections below detail the various elements available.

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Point

To create a point, use toolbar button 1 (keyboard shortcut G,Y) and click within the 3D viewport to place the point.

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Line

To create a line, use toolbar button 3 (keyboard shortcut G,L). Once the tool is active, select the mode in which the line should be created (cycle keyboard shortcut M). The mode defines the constraints presented by On-View-Parameters when the line is being created:

• Point, length, angle
• Point, width, height
• 2 points (no constraints presented)

Click within the 3D viewport to place the element and either fill out the On-View-Parameters or click again to place the second point.

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Rectangle

To create a rectangle, use toolbar button 6 to present a drop-down and either select ...

• Rectangle (keyboard shortcut G,R)
• Centered Rectangle (keyboard shortcut G,V)
• Rounded Rectangle (keyboard shortcut G,O)

The selection activates the tool with specific Rectangle Parameters preset. Those parameters can continue to be set once the tool is active:

• Mode: The mode in which the rectangle should be created (cycle keyboard shortcut M). Mode defines the constraints presented by On-View-Parameters when the rectangle is being created.
• Rounded corners: Whether the rectangle should have rounded corners (keyboard shortcut U). Rounded corners defines extra elements and constraints to be presented by On-View-Parameters when the rectangle is being created.
• Frame: Whether the rectangle should be a frame (keyboard shortcut J), as in have an inner and outer border. Frame defines extra elements and constraints to be presented by On-View-Parameters when the rectangle is being created.

Click within the 3D viewport to place the element and either fill out the On-View-Parameters or click until placement is complete.

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Polygon

To create a polygon, use toolbar button 7 to present a drop-down and either select ...

• Triangle (keyboard shortcut G,P,3).
• Square (keyboard shortcut G,P,4).
• Pentagon (keyboard shortcut G,P,5).
• Hexagon (keyboard shortcut G,P,6).
• Heptagon (keyboard shortcut G,P,7).
• Octagon (keyboard shortcut G,P,8).
• Polygon (keyboard shortcut G,P,R).

Except for Polygon, the selection activates the tool with specific Polygon Parameters preset. Those parameters can continue to be set once the tool is active:

• Mode: Select the number of sides for the polygon (keyboard shortcut U to increase, keyboard shortcut J to decrease).

Click within the 3D viewport to place the element and either fill out the On-View-Parameters or click until placement is complete.

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