PartBuddy designs FDM parts in conversation with an AI

PartBuddy 0.3.0 was released on November 10, 2026: a free Windows app without an account that lets you design parts for FDM printing in conversation with an AI. According to 3DRUCK, the program comes from the Austrian hobby developer Manuel Staggl, and the source code is under the GPL-3.0.

The assistant asks about loads, fits and real dimensions, shows a plan and creates the model only after your confirmation. The result is editable CAD geometry with a history, and every step can be undone. Whether the setup is worth it depends on the prerequisites, because the AI costs extra and part of the technology is still a pre-release version.

What does PartBuddy check after every change?

After every change, PartBuddy checks build volume, wall thickness, overhangs and adhesion to the print bed. The overhang angles depend on the material: 45 degrees for PLA, 40 degrees for PETG and ASA, 35 degrees for TPU. The app accepts bridges up to 10 mm and ribs up to 1.5 mm; wider ribs become slopes of 45 degrees. Horizontal holes from about 10 mm get a teardrop or flat roof.

According to the project page, PartBuddy specifies fits per material, measured with three test parts on your own printer. For snap-fit connections, the app calculates with about 1.4 percent strain and warns from 2 percent for PLA. For heat-set threaded inserts, the app knows standard dimensions: M2 with 3.2 mm diameter at 4 mm length, M3 with 4 mm diameter at 5.7 mm length. New in 0.3.0 are moving parts such as hinges and guides with a slider and a gap of at least 0.3 mm. Export is as 3MF, STL or STEP, and with one click the model goes to Bambu Studio or OrcaSlicer.

What do you need for PartBuddy to run?

PartBuddy runs only on Windows and requires the separate CAD program SolidCraft in version 0.40.0-rc.3, a pre-release version. With the older version 0.30.1, PartBuddy does start, but it does not open 0.40 projects. You bring the AI access yourself: a Claude subscription (Pro or Max), a ChatGPT subscription (Plus or Pro) or a local model, for example via Ollama or LM Studio. Local models need a context window of at least 16,000 tokens and must be capable of function calls.

PartBuddy shows its interface in English and German. According to the project page, the app collects no telemetry; the only connection of its own is the update check, which can be switched off. The installer is not digitally signed, so Windows SmartScreen may warn. Download it only from the project page and check before starting that the address is correct.

Where does PartBuddy stop?

PartBuddy does not plan supports and print orientation; your slicer takes care of that. Imported STL, 3MF and OBJ files are pure mesh models made of triangles, and their dimensions cannot be changed via the history, reports 3DRUCK. For later, the project page announces an MCP server, permissions per tool, a cost display and a purely local mode, without naming a date. The check values are default values of the app and do not replace a test on your printer.

What this means for you

First print the three test parts for the fits on your own printer before you have a bracket or a housing designed. Without this measurement, only the app's default values apply.

Before downloading, check that three things fit together: Windows, SolidCraft 0.40.0-rc.3 and an AI access. For a local model, a context window of 16,000 tokens and function calls count; a paid subscription to Claude or ChatGPT meets both. Start with a simple part, such as a bracket with a threaded insert, and only then have a hinge built. Before printing, check the slicer preview for supports and orientation, and make a note of when SolidCraft 0.40 is released in its final version, because only then will PartBuddy no longer depend on a pre-release version.

PartBuddy 0.3.0 was released on November 10, 2026, and 3DRUCK reported on the same day.

Sources

• PartBuddy: Parts that fit. First print.
• 3DRUCK: PartBuddy: Free Windows app designs print-ready FDM parts in conversation with an AI