Over Door Hook & Cabinet Towel Bar | Parametric

Customizable: the OpenSCAD source (.scad) is in the files. Open it in the free OpenSCAD app and use its Customizer panel (Window - Customizer) - that is what "Customize" refers to below.

A hook that sits on the top edge of a door or a kitchen cabinet door. No screws, no glue, no tools: measure the door, type the number into Customize, print, slide it on.

Hook. A U clip over the door top with one, two or three J hooks on the front. The part that crosses the door top is only 2.5 mm thick, so it fits the small gap between the door and the frame (or between a cabinet door and the countertop). A short tab goes down behind the door so the clip cannot tip off.

Towel bar. Two clips with a cradle each, plus a bar up to 240 mm long. The bar drops into the cradles and clicks in lightly over a chamfer on its top edge; an end cap on each end stops it sliding out sideways. You place the two clips anywhere between the caps.

What to measure (calipers):

• door_t - the thickness of the door at its top edge. Interior doors are usually 35-45 mm, cabinet doors 16-22 mm.
• The gap between the top of the door and the frame (or countertop) when the door is closed. Keep top_t (default 2.5 mm) at least 0.5 mm under it.

Files in the download: door 40 mm with 1 or 2 hooks, cabinet door 18 mm with 1 hook, cabinet towel set (2 brackets + 220 mm bar on one plate). Anything else: Customize.

Customize (the .scad is included):

• Preset: custom, door 35 / 40 / 45, cabinet 16 / 18 / 19 / 22 (sets the door thickness and a matching clip), or type your own numbers
• Door: thickness 10-60 mm, inside play (default 0.6 mm), bridge thickness 1.6-4 mm
• Clip: width, how far the back tab goes down, tab and plate thickness
• Hooks: 1-3, opening 10-60 mm, lip height, hook thickness, how far below the door top, spacing
• Towel bar: length 80-240 mm, cross-section, play in the cradle, how far below the door top, room for the towel
• It refuses settings that would give a broken part: hooks that overlap, a lip too low to hold anything, a bridge under 1.6 mm, a bar over 240 mm, a snap that does not fit the bar.

Numbers (checked on the STL files with a model door):

• Inside width = door + 0.6 mm. Dropped onto a model door the bridge sits on the door top; nothing is more than 2.5 mm above the door top, so it clears a frame 3 mm above the door.
• Hook opening 25 mm (door) / 18 mm (cabinet), lip 22 / 16 mm high. On the 2-hook version there is 22 mm between the lower lip and the upper hook to slide a loop in.
• Towel bar: 0.25 mm play per side in the cradle; the cradle lip flexes 0.30 mm to let the bar in (about 1 % strain); the bar sits 17 mm in front of the cabinet door so the towel has room.

Load: estimate only, NOT tested, not a rating. Simple statics with the measured sections and assumed material values (10 MPa for a load that hangs for months, about 40 MPa as a rough short-term break), one hook loaded at a time. Door hook: about 5.7 kg on one hook for months, short-term break around 23 kg (both hooks loaded together and the bridge between them were not calculated). Cabinet hook: about 4 kg / 16 kg. Towel set: about 3.7 kg in the middle of the bar, 1.4 mm sag under 2 kg. Treat these as orders of magnitude, not ratings. The hook is printed on its side, so the bending runs along the printed lines, not across the layers.

Print time / filament (Bambu Studio, P2S, 0.20 mm, PLA): door 1 hook 15 min / 11.2 g, door 2 hooks 26 min / 19.0 g, cabinet hook 8.5 min / 5.3 g, towel set (2 brackets + bar) 41 min / 27.9 g.

Prints without supports. The hooks and brackets lie on their side: the side view is on the bed and goes straight up, so every wall is vertical. The bar lies flat with only its top edges chamfered. Measured on the mesh: 0 mm² of surface steeper than 45 degrees on every file, and the slicer generated no supports.

PRINT SETTINGS: PETG recommended for anything that hangs for a long time or near heat (bathroom, radiator, kitchen); PLA works for light loads. 0.20 mm layers, 3-4 walls, 20 % infill or more, no supports, brim not needed.

Honest notes

• Not test-printed yet. Fits and load figures come from measuring the STL files and from statics, not from a real door.
• The back tab goes on the other side of the door. If that side has a door stop or a rebate (most rebated interior doors do), the door may close harder or not fully. Try it, or hang the hook on the side where the door has no stop.
• Cabinet doors: the back tab needs a little room between the door and the cabinet front. Check that the door still closes.
• The towel bar lifts out upward with a firm pull (the click is light); the caps only stop it sliding sideways.
• The pictures are 3D renders made from the same files; the doors and the towels in them are simple render props, not part of the download.