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Loop-the-loop marble runs
A steep drop, a vertical loop, then a U-turn back alongside to the finish. The track is an enclosed tube all the way, because at the top of the loop the marble is upside down.
Start from a preset
Each preset opens in the generator, ready to tweak, test and download.
How it works
- The loop shifts sideways by one track width as it goes round, so it comes out beside where it went in.
- A thin web spirals in from the tube to the loop’s centre and holds the loop’s top half up while it prints. Blocks under the loop’s bottom carry the rest.
- The drop is sized for the loop: if there isn’t enough height for the marble to get round, the loop is made smaller.
Settings you can change
| Loop radius | A bigger loop needs a taller run. |
|---|---|
| Start and finish | A funnel or open start, and a cup or vortex bowl at the end. |
Every style also lets you pick your printer, marble size (6 mm BBs to 25 mm shooters), groove shape, slope, wall height, base plate, label and colours.
Printing tips
Use a taller run and a steel ball for a big loop. The tube’s ceiling at the very top of the loop is a small round arch, which prints fine on most printers. Slice with supports off, 0.2 mm layers and 3–4 walls. The full print guide covers slicer settings and troubleshooting.
Other styles
- Spiral marble run towers: A spiral tower winds a track down around a central core.
- Zigzag marble runs: A zigzag run (or drop wall) sends the marble along a ramp, drops it onto the next ramp going the other way, and repeats all the way down.
- Freeform marble runs: A freeform run wanders across the printer bed in loops and bends, held up by fins with pointed arches (like a Roman aqueduct) or by thin pillars (like a roller coaster).
- Zigzag tower marble runs: A zigzag tower wraps a drop wall round a square core.
- Twin tower marble runs: Two spiral towers side by side, joined by a bridge on aqueduct arches.
- Racing marble runs: A wave racer is a zigzag wall with several identical lanes side by side.
- Vortex cascade marble runs: A vortex cascade is a chain of funnel bowls.