Cup Holder Car — rolling toy coupe with a drink well in the roof

A chunky toy coupe whose roof is a real drink well. Push it along the desk and the four wheels actually roll. Park it and drop a can, glass or small cup into the roof.

What It Is

- A rounded toy-car body about 196 mm long with sloped hood, raked cabin, engraved windshield, side windows, headlights, grille and taillights.

- A 73 mm cylindrical well sunk 56 mm into the cabin roof. It holds a 70 mm can, small cup or glass. A 12 mm drain and finger through-hole runs from the well floor out the underside to drain spills and push the cup out.

- Four chunky free-spinning wheels with dished hubcaps and lug dimples on two captive axle rods.

HOW THE WHEELS ROLL Each wheel bore rides a smooth axle journal with 0.2 mm radial clearance, acting as the bearing for a low-friction free spin. An internal retaining rib in the wheel snaps into a groove turned near the axle tip. Relief slots split the snap zone into flexing fingers, so the hub springs over the tip during assembly with a firm click. The wheel is then captive yet spins freely, and can be pulled straight off again. The two wheels keep each axle captive in the body. All parts print separately, so no clearance can fuse.

Recommended Material

PRINT THE AXLES IN PETG. The axle rods are the load-bearing part. They carry the car and drink weight on slender journals and their tip lands flex every time a wheel snaps on or off. PETG toughness keeps the snap lands from shearing and the rods from creeping under load, where PLA can snap brittle. Body and wheels are fine in PLA, and PETG everywhere is even better for daily use.

PARTS (separate STLs)

- cup_holder_car_body.stl: car body with well, fenders and axle bores, print 1

- cup_holder_car_wheel.stl: one wheel, print 4

- cup_holder_car_axle.stl: one axle rod, print 2, PETG recommended

- cup_holder_car.scad: full parametric source

PRINT: all parts flat, NO supports.

- Body prints on its flat underside with the roof and well facing up. Hood and windshield slopes stay under 45 degrees and the axle bores are teardrop-bridged so they print round.

- Wheel prints inner web face down, full disc on the bed, hubcap up.

- Axle lies flat on the bed.

ASSEMBLY (no glue, no tools): feed an axle through a pair of body bores, push a wheel onto each protruding tip until it clicks. Repeat for the rear axle. Done. It rolls.

Multi-Colour (Ams)

body, wheel and axle are separate STLs. Assign a filament to each in the slicer, for example blue body, black wheels, white axles. Parts mate by the printed snap, so no coordinate locking is needed.

Customising

everything is parametric at the top of the .scad file, including well diameter, well depth, wheel size, body length, bearing clearance and snap-rib interference.