Swirl Sink Cup – Self-Draining Toothbrush Holder that Empties into the Sink

Stop the gunk at the bottom of your toothbrush cup Every toothbrush cup ends up with a puddle of water and toothpaste at the bottom. This one doesn't hold water at all: the floor is a funnel that leads to a spout, and the spout hangs over your sink. Whatever drips off your brushes ends up in the sink. How it works - Removable grid: your brushes, toothpaste and razor stand on a perforated grid. The holes are countersunk, so drops slide in instead of sitting on flat plastic.

- 25° funnel: water falls on a steep cone. Steep on purpose: on a 3D print, a gentle slope is a staircase of tiny flat ledges where drops get stuck. At 25° each ledge is only 0.4 mm wide.

- Open U-channel: the funnel feeds a rounded channel that runs at 6° to the tip of the spout. It's open along its whole length inside the cup, so there's no hidden tunnel to grow mould.

- Drip edge: a chamfer under the spout tip makes water drop off cleanly instead of creeping back under the cup.

All openings are at least 6 mm wide, more than twice the capillary length of water (2.7 mm), so a drop can't plug a hole by surface tension. Sized for what you actually put in it - The rim sits 100 mm above the grid, about half the length of a manual toothbrush (19–20 cm). That's above the brush's centre of gravity, so it won't tip out, and the bristles stay well clear to air-dry.

- Ø 78 mm inside: 4 brushes plus a 75 ml toothpaste tube (cap down), or an electric toothbrush handle.

- Lift the grid out by its centre knob and rinse the funnel under the tap.

Printing - Cup: upright, no supports. The passage under the front wall is a short 10 mm bridge.

- Grid: flat, knob up, no supports.

- PETG recommended (tougher, doesn't soften with warm water). PLA is fine for a test.

- 3 walls, 15 % infill, at least 5 top layers so the floor is watertight.

- Turn on ironing (top surfaces): it smooths the funnel and the channel so water runs even better.

- Seam: aligned or back, so it doesn't scatter dots over the flutes.

Placement Put the cup on the edge of the sink with the spout over the basin. The spout sticks out about 25 mm in front of the cup. Dimensions - Cup: Ø 96 mm at the rim, 136 mm tall, 120 mm deep including the spout

- Grid: Ø 77 mm

- Usable height above the grid: 100 mm