Describe the part you need. PartBuddy asks what matters, builds real, editable CAD while you watch, and checks it against your printer before you slice.
Free · For Windows · Your Claude or ChatGPT plan, or a local model
Needs the free CAD engine SolidCraft 0.40.0-rc.3.
Works with
How it works
One workspace, four steps. Everything you see is the app as it is today.
01Ask
Say what the part is for, in words, with a sketch or a photo. PartBuddy offers concepts based on proven designs, asks about loads, cables and the real sizes of your things, and shows a plan. Nothing is built until you press Go.
02Build
SolidCraft builds editable solid geometry step by step in the 3D view. Click a face, pin a note to it and ask for the change in words, or change a size right in the parameter table. Every step, yours or the assistant’s, can be taken back.
03Check
After every change, PartBuddy checks the part against your printer and material and points at each finding. The assistant sees the result too, and the standards behind the numbers are built in.
| Material | Clamp | Push | Slide | Turn | Overhang |
|---|---|---|---|---|---|
| PLA | 0.05 | 0.15 | 0.25 | 0.30 | 45° |
| PETG · ASA | 0.10 | 0.20 | 0.30 | 0.35 | 40° |
| TPU | 0 | 0.10 | 0.30 | 0.40 | 35° |
The defaults. Your printer and material profile changes them.
Seats 1 mm deeper than the insert, bosses with at least 2 mm of wall.
04Print
Every part on its print face, nested on the bed of your printer. Open it in Bambu Studio or OrcaSlicer with one click, or export 3MF, STEP and STL. Supports and orientation stay with your slicer.
Workspace
The parts of a CAD workspace you expect, built for makers.
Exploded views along the directions the parts go together, and sections along any axis or flat face.
The assembly plays step by step in the right order, sub-assemblies first, set by the assistant or proposed from the geometry.
Draw it on squared paper and type 40, Ø 8 or R 3. The assistant builds from them.
It asks for the one size that sets the scale. It never guesses from pixels.
Click a face, edge or point and pin a note to it: “this edge R2 instead of R1”. The assistant reads it, the note follows its face through rebuilds, says so if it loses its place, and travels with the design file.
Saved before every request. Keep any of them as a milestone, compare it with now or open it as a project of its own.
Pick a material from the catalog, print three small test pieces and enter what fits. Clearances, holes and overhang then match your printer.
Per chat. With a Claude plan you see how much of it you have used.
Import STEP and IGES as editable bodies, STL, 3MF and OBJ as meshes.
Compare
There are four usual ways to get a functional printed part today. Each solves one part of the problem.
| Classic CAD | Text-to-3D generator | Chatbot writing CAD code | Chatbot connected to SolidCraft | PartBuddy | |
|---|---|---|---|---|---|
| Exact, editable geometry (STEP) | Yes | NoMesh | YesAs code | YesSame engine | YesWith full history |
| Describe the part in words | No | Yes | Yes | Yes | YesOr a sketch or photo |
| Asks about loads, fits and real sizes | NoYou decide alone | No | PartlyIf you ask it to | PartlyIf you ask it to | YesBefore it builds |
| ISO fasteners, inserts and fits built in | PartlyLibraries, by hand | No | PartlyIf it knows them | PartlyIf it knows them | YesSized per material |
| Checked against your printer | PartlyAdd-ons | No | No | No | YesAfter every change |
| See and change every step in 3D | Yes | No | PartlyAfter each run | PartlyFaces named in words | YesClick a face, ask in words |
| Notes pinned to the model | PartlyComments, for people | No | No | No | YesThe assistant reads them |
Typical for each kind of tool; single products differ.
Privacy
Projects are plain folders on your computer, sign-ins stay in the Windows credential store, and the app sends no telemetry. Its only call of its own is the update check, and you can turn that off. No account, no cloud of its own.
Use your Claude or ChatGPT subscription, or keep everything on your machine with a local model.
This website sets no cookies and loads nothing from other servers.
0.1.0
Download PartBuddy for Windows. Free, open source, no account.
PartBuddy is free and a hobby project. If it saves you a print, you can buy it a coffee. Entirely voluntary.
Support on Ko-fiNothing. PartBuddy is free and open source under the GPL-3.0 licence.
The assistant runs on a subscription you already have or on a local model. PartBuddy adds no fees of its own.
Claude Pro or Max (through Claude Code), or ChatGPT Plus or Pro. With a local model you need none of them.
Yes, with Ollama, LM Studio, llama.cpp, vLLM or Strata. PartBuddy finds local servers on this computer and offers only models that can call tools and have at least 16K context.
Real CAD. SolidCraft builds editable solid geometry with a full history, so you can change any size later and export STEP for other CAD programs as well as 3MF and STL for printing.
No, on purpose. That is slicer work, and your slicer knows your printer profile. PartBuddy designs the part, checks what can only be decided while designing, and opens it in Bambu Studio or OrcaSlicer.
Yes. PartBuddy is a Windows desktop app.
The CAD engine behind PartBuddy. It builds the geometry; PartBuddy runs it in the background and shows every step in its own 3D view. You install SolidCraft yourself, and the setup on first start helps you find it.
SolidCraft 0.40.0-rc.3, a pre-release. Download SolidCraft-0.40.0-rc.3-windows-x64.exe from its release page; the release marked “Latest” on SolidCraft’s GitHub page is still the older 0.30.1.
The older SolidCraft 0.30.1 starts too, but PartBuddy is only tested with 0.40.0-rc.3, and 0.30.1 can’t open designs saved by 0.40.
You can: SolidCraft has its own MCP server, and PartBuddy drives the same engine. What PartBuddy adds is everything around it.
It asks about loads, fits and real sizes and shows a plan before it builds. It checks every change against your printer and material. ISO fasteners, inserts and fits measured on your printer are built in. You click a face and pin a note to it, so the assistant knows exactly which face you mean, even after a rebuild.
The assistant works only through PartBuddy’s checks and only in your project folder. Every step can be taken back, versions can be compared, and the part goes straight to your slicer. And there is nothing to configure: sign in with your plan and start.
PartBuddy is a hobby project and its installer is not code-signed, so Windows SmartScreen may show a warning. Choose More info, then Run anyway. The source code is public.
