30mm Modular Marble Run | 100+ Snap-Together Parts

Designer

OverEngineer

Designer relation

Ingen

Kategori

Toys & Games

Licens

Standard Digital File License

$ ↺

Se platformens konkrete vilkår.

Designer commercial

None

Først set

2026-09-17 04:00

Sidst set

2026-09-17 04:00

Tags

marble run marble track modular building system snap fit murmelbahn steel ball construction toy stem expandable marble machine kids gift no glue

Beskrivelse

A snap-together marble run built around a big 30 mm ball. Large parts, one connector, no glue. Every part plugs into the next with a press-fit tenon and socket, level changes are pinned → once a track is built, it stays built. Start with a small loop on the table and grow it as far as you like: my biggest track so far uses 122 parts and covers 78 × 105 cm. Why a 30 mm ball? I designed this for my two small kids. The marbles in the usual marble runs are small enough for a toddler to swallow, and I was never comfortable having them around the house. So I built a track around a 30 mm steel ball instead, and made every part big to match. In our living room the one-year-old drops the ball in and watches it go, and the three-year-old builds her own tracks. The big parts turned out to be the best thing about the design: nothing is fiddly, and the heavy ball makes a satisfying noise. Boost Me (for free) If this saves you from tiny marbles too, a free boost is the best thank-you & it pays for the filament to test the next part. Thanks! Boost What you need One steel ball, Ø 30 mm. A plain bearing ball (grade G100 is fine) costs a few euros at any bearing supplier or online. A 30 mm glass marble rolls too, but it is much lighter, and the brakes and banked curves are tuned for steel, but it will work nevertheless! Filament. Nothing else – no screws, no magnets, no glue. The system One footprint, three heights. Every part sits on a 120 × 50 mm grid with track levels 40, 50 and 60. The name says what a part does: Straight120_60-50 is a 120 mm straight dropping from level 60 to 50. Unlimited Rims/Layers: a Layer starts at level 60 and ends on level 40, change Layers with Funnels, Slides, Spirals, … Two track styles. A closed groove – quiet and forgiving – and an open rail where you have to watch your speeds and that lets you watch the ball and uses less filament. Same connector, mix them freely. Build up with adapters. Adapters stack to gain height; a ribbed pin locks each stack. In the set: straights, curves in two radii, spacers, hills, banked curves, brake sections, a spiral, a slide, a vortex funnel, a zigzag tower, a crossing, tunnel adapters, start ramp and end cup – 100+ parts plus a fit-test coupon and the pins. New parts are added over time (see below). Printing – easy by design Chunky solid parts, no fine features. Bambu Lab A1, 0.4 mm nozzle, PLA Basic, 3 walls, 2–5 % gyroid – that is all they need. Supports: minimal. The profile has small painted supports under the socket ceilings and nowhere else. They come off in one piece. Everything in the photos was printed this way. No supports also works. The socket still fits, the ceiling just looks rougher inside. See the three comparison photos in the gallery: no support / PLA support / support filament. For a perfect socket: with an AMS, use Bambu Support for PLA/PETG as the support interface. Nice to have, not required. Layer height 0.24mm, first layer 0.25mm so the sockets stay clean , bridges slow, fan 100 %. If you print without supports: socket should face east or west. Print only what you need. Plate 1 is deliberately empty: copy the parts you want onto it and print just that plate. Plate 2 holds pins to duplicate; every other plate holds each part exactly once, grouped by family. The whole set is roughly 5kg of filament – nobody needs all of it. A few straights, four curves, two adapters and the two cups already make a track that runs. (Actually I used 7 rolls of Landu Filament for the big marble run) Assembly Push the tenon into the socket until the faces meet – it needs a firm push, that is the press fit. For a level change, stack adapters and drop a pin through. Print the FitTest coupon first and check the fit before you commit to twenty plates; if it is too tight, lower the flow ratio by 0.01 rather than sanding. Missing a part? Tell me. This is a system, and it keeps growing. If you need a part that does not exist yet, or have an idea for a new element, write it in the comm