Support

No. Every underside is limited to the “Max overhang” angle (45° by default), and tracks that cross get pointed-arch tunnels that print cleanly. Slice the file as it is with supports turned off.

• 0.2 mm layers, 3–4 walls, 10–15% infill.
• 0.12 mm layers or ironing on the track make the marble roll faster and quieter.
• PLA or PETG both work. Use a contrasting colour for the track so you can follow the marble.

No, that’s on purpose. The track, supports, base and label are separate shells that slicers merge automatically. The 3MF keeps them as separate parts so you can give each its own colour on AMS/MMU printers.

Choose your printer under Size & printer and the generator fits the run to its bed. A warning appears if a setting pushes it over. For towers, lowering the slope or using a smaller marble makes the core narrower.

Choose Gate slot + queue as the start. The gate card is a separate part that prints flat. Slide it into the slot, line up your marbles behind it, then lift it to race.

Pick the exact marble in the Marble section. Steel bearing balls (6–12.7 mm) are cheap, perfectly round and run smoothly. Glass marbles (14–16 mm) look great but vary in size, so measure yours with calipers and use Custom if they’re off. Print the test piece from the Download menu to check the fit.

Red rings in the preview show where the simulator predicts problems. Click Auto-tune slope under Track, raise the walls, turn on auto-banking or switch to the tube groove. Rough first layers and stringing also slow marbles down, so ironing helps.

3MF for multi-colour printing (Bambu Studio, PrusaSlicer, OrcaSlicer). STL for any slicer. ZIP for one STL per colour plus print notes. Settings (.json) to reopen your design later.

Yes, with a Commercial licence. It lets you sell unlimited physical prints of runs you design. Free and Pro cover personal, gift and classroom use. Nobody may resell the digital files. See the terms.

Send us a message below with the run’s link and we’ll take it down.