Choose the tooth count, belt width and bore — the outside diameter comes out exactly as on aluminium GT2 pulleys (20 teeth: 12.22 mm), with flanges, a hub and two set screws in captive nut traps. Gates doesn't publish the GT2 groove, so each groove is built from the belt's published tooth shape, with a fit setting for your printer.
The real generator runs in your browser: set the parameters, then download STEP or STL. Nothing to install, no sign-up.
The first open downloads the CAD engine (about 20 MB).
Each parameter below rebuilds real geometry on every change — this is parametric CAD, not a scaled mesh.
| Parameter | Default | Range | What it does |
|---|---|---|---|
| Belt profilePROFILE | GT2 2 mm | GT2 2 mm / GT2 3 mm | 2 mm pitch is the 3D-printer belt. |
| Number of teethTEETH | 20 | 16 – 60 | Outside diameter = teeth × 2 / π − 0.508 (20 teeth: 12.22 mm); one turn moves teeth × 2 mm of belt. Up to 60, MISUMI's largest stock 2GT pulley. |
| Belt widthBELT_WIDTH | 6 mm | 4 – 15 | The toothed part is 1 mm wider, as on MISUMI pulleys. |
| Groove fitFIT | 0.2 mm | −0.1 – 0.3 | Widens every groove for printing; move in 0.1 steps. |
| FlangesFLANGES | both | both / bottom / none | Outside diameter + 5 mm, 1.5 mm thick: they keep the belt on. |
| BoreBORE_D | 5 mm | 2 – 8 | Shaft size; 0.15 mm of print clearance is added. 5 for NEMA 17 motors. |
| HubHUB | hub | hub / none | None makes an idler: just the toothed body and flanges. |
| Set screwsSET_SCREWS | 2 | 0 – 2 | In the hub, 90° apart, with captive nut traps; M3 up to a 5 mm bore, M4 above. |
Every parameter can go in the page's link, so one link opens exactly the part you want. Example (40 teeth, 8 mm bore):https://www.forgent3d.com/en/generators/gt2-pulley-generator?TEETH=40&BORE_D=8
STEP AP214 in millimetres, exact B-rep — it opens directly in SolidWorks, Fusion, FreeCAD, Onshape or Inventor, and goes straight into a CNC quote form. STL for the slicer is one click too.
| This generator | Typical online STL generator | Vendor CAD library | |
|---|---|---|---|
| Any size within the range | Yes | Yes | Catalog sizes only |
| STEP with exact surfaces | Yes | Usually an STL mesh only | Yes |
| Changes the sliders don't cover | “AI edit” on the page | No | No |
| Account needed to download | No | Usually no | Often |
Every parameter is a link parameter; the link below opens the example part. ChatGPT, Claude or any assistant can write one like it from the parameter list (names, units, ranges) at: parameter list (JSON)
Example: https://www.forgent3d.com/en/generators/gt2-pulley-generator?TEETH=40&BORE_D=8
Press “AI edit” in the generator and say what to change — a keyway, holes, a different shape. The AI edits the part's model.py and it rebuilds in your browser, with undo. A few edits a day are free without signing in; to keep the result or go further, copy it into your models and continue with the AI agent.
Edit with AI →For bigger changes, several rounds, or a part you want to keep: copy it into your models (free account). The Forgent3D AI agent reads the model.py, edits it, rebuilds it and checks the result itself.
Copy and continue with the AI agent →This generator goes down to 16 teeth. Below about 20 the belt has few teeth in mesh, and the pulley's tooth tips are only a few tenths of a millimetre wide at any tooth count — about one 0.4 mm line — so many makers print 20 or more.
Flat on the bed, flange down, no supports; 0.1–0.16 mm layers for the teeth, external perimeters first, at least 4 walls. PETG, ABS, ASA or nylon; PLA for light loads only.
One turn moves teeth × 2 mm of belt: 40 mm for 20 teeth. A 200-step motor at 16 microsteps makes 3200 steps per turn, so 3200 / 40 = 80 steps/mm.
https://www.forgent3d.com/en/generators/gt2-pulley-generator?TEETH=20&BORE_D=5&BELT_WIDTH=6 — 12.22 mm outside diameter like the aluminium ones, flanges, and two M3 set screws in captive nut traps. Download STL to print it flange down, no supports.
FIT widens every groove: start at 0.2 (droftarts' default) and move 0.1 at a time — https://www.forgent3d.com/en/generators/gt2-pulley-generator?FIT=0.3 — then print the teeth with 0.1–0.16 mm layers, external perimeters first and 4 or more walls.
Yes. Models you generate and the STL / STEP files you export are yours: print them, sell the prints, or use them in a product. No attribution to Forgent3D is required.
Already have your own .scad file? Convert OpenSCAD to STEP → · Preview it in the browser →
