3D-print a track

Print notes

• Bed fit: pieces are automatically segmented so every one fits the selected printer (256 mm on the X1 Carbon). Splits happen at natural block seams — every segment stays a closed solid. Anything that still can't fit is flagged red; drop the piece size a notch.
• Modular: pieces are numbered in track order (01, 02, …) and segments stack bottom-up (a under b under c). Print, stack, glue, race.
• Scale: at 40 mm/cell the channel fits a standard 16 mm marble. Check "assembled size" before committing — these courses are tall towers.
• Slicing: pieces are overlapping closed shells — modern slicers (Bambu Studio, PrusaSlicer, Cura) union them automatically. If yours complains, enable merge-overlapping-volumes or run its repair tool.
• Supports: anything that would print in mid-air (banner bars, arch tops, floating decorations) gets a slim 3 mm breakaway pillar baked in — gray in the preview. Print with slicer supports OFF, then snap the pillars off after printing. Untick "bake breakaway supports" if you'd rather use your slicer's own.
• Plastic: chunky tower blocks are hollowed into square tubes — an open shaft straight through, so there's no infill and no bridging inside, and stacked blocks line up into one continuous channel. Floors and walls stay solid (a marble track with holes in the floor is a different game). Untick "hollow big blocks" for solid pieces.
• Orientation: files are Z-up with each piece resting at Z=0.
• The same seed always builds the same track — print the course your favorite race ran on. 🏁