Printed and run on a GT2 belt: the 45-tooth pulley is cut down to three spokes on a 1 mm web, both pulleys print their flanges in place on breakaway supports, and two M3 set screws per hub bite into captured nuts.
Using the CheapCAD Tools connector, design a two-pulley timing belt drive: GT2 belt (2 mm pitch), 5.5 mm wide, about 62.32 mm between centres. Pulley 1: 30 teeth, 5 mm bore, 0.2 mm print compensation, a hub 20 mm across and 6 mm tall with two M3 set screws in captured nuts. Pulley 2: 45 teeth, 5 mm bore, a hub 13.35 mm across and 10 mm tall with two M3 set screws in captured nuts, and 3 spokes 6.55 mm wide on a 1 mm web round a 13.35 mm spoke hub, a 3 mm rim under the teeth and 2.5 mm fillets at the hub. Both pulleys: printed flanges 2 mm thick, the top flange printed in place on breakaway print supports. Check the design, apply any Auto-fix it suggests, then export both pulleys as STL and give me the download link.
Paste it into Claude, ChatGPT or any AI app with the CheapCAD Tools connector, and it designs this drive with you, checks it and hands you the files. How to connect your AI.
GT-2M-30T.stl — pulley 1, 30 teeth, without supportsGT-2M-45T-P2.stl — pulley 2, 45 teeth, without supportsGT-2M-30T-w-supports.stl — pulley 1 with breakaway supports under its top flange: print this oneGT-2M-45T-P2-w-supports.stl — pulley 2 with breakaway supports under its top flange: print this oneFree STLs are CC BY 4.0, exactly the design that was printed for the photos, with its print compensation (pulley 1 0.2 mm). Open the design to change anything, tune the fit for your printer, or download STEP, DXF, SVG and the belt.
| Pulley 1 | Pulley 2 | |
|---|---|---|
| Pitch diameter | 19.10 mm | 28.65 mm |
| Outside diameter | 18.59 mm | 28.14 mm |
| Outside diameter, as built | 18.21 mm | 28.16 mm |
| Root diameter | 17.06 mm | 26.61 mm |
| Groove depth | 0.76 mm | 0.76 mm |
| Pitch line differential | 0.25 mm | 0.25 mm |
| Belt width | 5.50 mm | 5.50 mm |
| Face width (belt + clearance) | 6.50 mm | 6.50 mm |
| Minimum face width | 6.50 mm | 6.50 mm |
| Flange outside diameter | 24.21 mm | 34.16 mm |
| Flange past the OD | 3.00 mm | 3.00 mm |
| Minimum flange height | 1.10 mm | 1.10 mm |
| Flange inward of the groove | — | 3.00 mm |
| Minimum flange overlap | — | 3.00 mm≈ |
| Belt | 100 teeth · 200.00 mm | |
| Centre distance | 62.32 mm | |
| Drive ratio | 30 : 45 · 1 : 1.5 | |
Read from the generator's Dimensions panel for this design, which opens with no warnings.
The 3D-printer classic done properly: a D-flat that keys onto the motor shaft, a set screw that bites into a captured nut instead of the plastic, and a 30-tooth partner held by two heat-set inserts.
Big printed pulleys don't need to be solid: five and six spokes on a thin centre web cut plastic and print time, while the toothed rim stays full width for the belt.
Tuned for positioning rather than power: tight tooth clearance, no backlash allowance and 0.1 mm of print compensation, so the printed teeth hold the belt without slop.
Printed and run on an S5M 690 belt: a 1 : 5 reduction to a 100-tooth wheel on eight spokes, whose top flange prints as a separate ring and glues on over 40 nubs, while the 20-tooth pulley prints its flanges in place.