Articles on: Integrations & automation

The FreeCAD integration: send parametric models straight to SimplyPrint

The FreeCAD integration: send parametric models straight to SimplyPrint


The SimplyPrint addon for FreeCAD lets you tessellate parametric solids on the fly and upload them to your SimplyPrint account in one click. Pick STL, 3MF or OBJ, choose mesh quality, press Send, and the file lands in SimplyPrint ready to slice and print.


What you can do

  • Export STL, 3MF or OBJ directly from FreeCAD to SimplyPrint
  • Adjustable mesh quality - Low / Medium / High presets, or a custom surface deviation (mm) and angular deviation (°) for curved parts
  • Physical bounding box (mm) and volume (cm³) preview - catch unit or scale mistakes before you upload
  • Context-aware panel that adapts to the active workbench (Part, Part Design, Mesh, Assembly)
  • Send the whole document, just your selection, or one file per object
  • Sign in once - the SimplyPrint session is independent from your Blender, Fusion 360, Onshape and Cura plugins, so signing out here won't touch them
  • Works on Windows, macOS and Linux (native and flatpak)


Install the addon

The SimplyPrint addon is free and works on FreeCAD 0.21 or newer, including 1.0. You'll need a SimplyPrint account to sign in afterwards.


  1. In FreeCAD, go to Tools → Addon Manager.
  2. Search for SimplyPrint in the list, click Install, and approve any prompts FreeCAD shows.
  3. Restart FreeCAD. The SimplyPrint dock panel and workbench appear.


Option 2 - Manual zip install (Windows, macOS, Linux)

  1. Download SimplyPrint.zip.
  2. Find your FreeCAD user Mod/ folder. The simplest way is to open FreeCAD's Tools → Edit parameters… and look up Mod path under BaseApp/Preferences/Macro, or run App.getUserAppDataDir() in FreeCAD's Python console and append /Mod to the result.
  3. Extract the zip into that folder so you end up with a Mod/SimplyPrint/ directory.
  4. Restart FreeCAD.


Where to find it

Once installed, the addon shows up in a few places so you can reach it from wherever you're working:


SimplyPrint dock panel

A dockable SimplyPrint panel appears on the right of the FreeCAD window. It's available in every workbench and adapts to what you're doing - solids in Part / Part Design, meshes in Mesh, the whole assembly in Assembly.


SimplyPrint dock panel inside FreeCAD with objects listed and mesh quality controls


SimplyPrint workbench

A SimplyPrint workbench is added to the workbench dropdown. Switch to it for a dedicated toolbar and menu - useful if you've closed the dock panel and want to reopen it with one click.


Toolbar and menu

Inside the SimplyPrint workbench, you'll find Log In / Log Out, Open Panel, and Send to SimplyPrint buttons on the toolbar and in the menu bar.


How to send a FreeCAD model to SimplyPrint

  1. Open the document you want to print in FreeCAD.
  2. Open the SimplyPrint dock panel. If it's not already visible, switch to the SimplyPrint workbench and click Open Panel, or pick it from View → Panels → SimplyPrint.
  3. The first time you use the addon, click Log In. A browser tab opens with SimplyPrint's sign-in page - approve the request and return to FreeCAD. You stay signed in for future exports.
  4. Pick your format and options (see below), tick the objects you want to send, then click Send to SimplyPrint.
  5. SimplyPrint opens in your browser with the file pre-loaded, ready to slice, queue, or print on one or more printers.


Options explained


Format

Option

When to use

STL (binary)

Universal mesh format - every slicer reads it. Pick this if you're not sure.

3MF

Newer format that preserves millimeter units and bundles multiple objects in one file. Great for multi-body prints.

OBJ

Lightweight alternative when a downstream tool specifically asks for OBJ. STL or 3MF are usually a better choice for slicing.


Mesh quality

Controls how finely FreeCAD tessellates parametric solids into triangles. Higher quality means smoother curves and larger files. Only shown when the active workbench actually has solids to tessellate (Part, Part Design, Assembly) - in the Mesh workbench, meshes are sent as-is.


Preset

What you get

Low

Coarse triangulation. Fast export, great for quick fit checks and test prints.

Medium

Balanced. The recommended default for most prints.

High

Fine triangulation, smoother curves, larger file. Best for show-piece prints with curved surfaces.

Custom

Exposes the surface deviation (mm) and angular deviation (°) sliders for full control.


Scope

Option

What it sends

Whole document

Every printable object in the document.

Selection only

Just the objects you've selected in the tree or 3D view.

One file per object

Each object exports as its own file - each lands in SimplyPrint as a separate card.


How each workbench is handled

The SimplyPrint panel adapts its UI to the active workbench, so you only see options that make sense for what you're doing:


  • Part / Part Design - the panel lists the solids it found and shows the mesh quality controls. Pick which ones to send.
  • Mesh - meshes are sent as-is, so the tessellation controls are hidden. The panel just lists the meshes in the document.
  • Assembly - the whole assembly is sent as one file by default. Pick One file per object if you want each part as its own export.
  • Sketcher / Draft / TechDraw / and other 2D-first workbenches - the panel shows a hint to switch to a printable context. There's nothing to send from a sketch alone.


Signing out or switching accounts

Click Log Out in the SimplyPrint dock panel (or use the Log Out button in the SimplyPrint workbench toolbar) to end the current session. Sign in again with a different account next time. Signing out here doesn't affect any other SimplyPrint plugins you may have installed (Blender, Cura, Fusion 360, Onshape) - each one handles its own session independently.


Requirements

  • FreeCAD 0.21 or newer (including 1.0)
  • Internet access to https://simplyprint.io
  • Windows, macOS or Linux (native or flatpak)


Troubleshooting


Sign-in window opens but never returns.

The addon needs to talk to your browser on a local port to receive the SimplyPrint sign-in. Firewalls, another running FreeCAD session, or an unrelated process holding the port can block it. Close any extra FreeCAD windows, try a different default browser, and restart FreeCAD.


The SimplyPrint dock panel is missing.

Open View → Panels and tick SimplyPrint to bring it back, or switch to the SimplyPrint workbench from the workbench dropdown and click Open Panel.


Curved parts look faceted in SimplyPrint.

Bump mesh quality up to High, or switch to Custom and lower the surface deviation (try 0.05 mm for a smoother curve). The trade-off is a bigger file and a slower export - usually worth it for show-piece prints.


The Assembly export is empty.

Make sure the Assembly workbench is active and the assembly has solved parts. The addon reads tessellated geometry from the assembly, so an unsolved or empty assembly produces nothing to send.


"No printable objects found."

You're probably in a 2D-first workbench (Sketcher, Draft, TechDraw). Switch to Part, Part Design, Mesh or Assembly - the panel hint at the top of the dock walks you through what to do.


3MF or OBJ option is missing.

Older FreeCAD builds may not ship the corresponding exporter. Update FreeCAD to 0.21 or newer (1.0 ships them all), or stick with STL.

Updated on: 28/06/2026

Was this article helpful?

Share your feedback

Cancel

Thank you!