Parametric Oval Slotted Tube — any bore, wall, length & slot position

An oval channel with a slot running the full length. Set the bore width and height independently, pick your wall thickness and length, and choose which side the slot sits on — top, bottom, left, right, or any angle you like.

The oval shape is the point. A round tube wastes height when what you're routing is wide and flat: a cable ribbon, a bundle lying side by side, a strip, a flat rod. An oval bore hugs it, so the part stays low profile and takes up less room against a surface.

Default configuration: 25 × 15 mm bore, 3 mm wall, 200 mm long, 12 mm slot on top.

What you can adjust

The outside dimensions follow automatically: inner size plus twice the wall. At the defaults that's 31 × 21 mm.

About the wall

The wall is a true constant-thickness offset, not two stacked ellipses. Subtracting one ellipse from a slightly larger one looks right in a preview but leaves the wall thin at the ends of the long axis — exactly where an oval channel gets flexed. Here 3 mm means 3 mm everywhere.

The slot edges are cut parallel, not radial. On an oval that reads cleaner, and it clips over things more predictably, because the gap is the same width no matter how deep you measure it.

What it's for

• Flat cable runs — ribbon cable, a bundle lying side by side, or several cords in a row
• Low-profile routing along a desk edge, frame rail or wall, where a round tube would stand too proud
• Snap-on covers for oval rails, handles and extrusions
• Guides and tracks for flat stock, straps and belts
• Sleeves and edge protection for a hose, sensor lead or exposed edge

Printing notes

Orientation. The model comes out standing on end, axis vertical. That gives the cleanest bore with no supports. Add a brim past roughly 120 mm tall.

Lying down works too, and gives stronger layers along the length. Rotate it so the slot faces straight up: the flat side of the oval then sits on the bed and you get a wide, stable contact patch — one of the real advantages of the oval over the round version.

Settings that matter.

• 3 or more perimeters — on a part this thin, the walls are the strength
• 0.2 mm layers are fine; 0.12 mm if something has to slide through smoothly
• 15–20 % infill; below a 2 mm wall it's all perimeter anyway
• PETG or PLA indoors, PETG or ASA outdoors

Fit. Printers over-extrude into holes. If the bore has to slide over something, add 0.2–0.4 mm to both bore dimensions and test a 20 mm long version first — it prints in minutes and saves a failed 200 mm part.

Slot width. The wider the slot, the more the channel springs open. Past about two thirds of the width of that side it stops holding anything in. If you want a snap fit, start narrower than the thing you're clipping over and let the walls flex.

Also available

Prefer a plain round tube? I have a round version as a separate model with an angle-based slot. This one covers round too — set the inner width and height to the same number.

Built in OpenSCAD. One solid body, watertight, no supports, no assembly.

If you print one, post a make. Found a use I didn't list? Drop it in the comments and I'll add it.