Cat Ear Headphone Inserts for Capra Headband v3 - 2 Thicknesses, 3 Fits

The two cat-ear pockets of the Capra Headband V3 TPU headphone band (cat ears version) are empty by default. These cat ear inserts fill them with a second colour: print them in another filament, glue or tape them in, and each ear gets a coloured inner face.

The shape was taken from the original band STL rather than drawn by eye. I sliced the pocket every 0.025 mm and let the insert follow its sloped walls, and every layer fits through the ones above it. So the insert drops in from the top and prints without supports.

Which insert to print

There are twelve STL files: two thicknesses, three fits, a left and a right of each. Thickness decides how it looks, and gap decides how you mount it.

Thickness - how it looks

• 2.0 mm - recessed. It sits 2 mm below the ear rim, so a white TPU wall frames the colour.

• 3.8 mm - near flush. It fills the 4.0 mm pocket and stops 0.2 mm below the rim, clear of the rounded edge, so it never pokes out.

Gap - how you mount it (the space between insert and pocket wall, on every side)

• 0.00 mm - for foam tape (double-sided, 0.5-1 mm). The pocket walls slope outward by about 29 degrees, so once the tape lifts the insert off the floor it gets 0.27-0.55 mm of room per side. Use it with the 2.0 mm thickness only, because a 3.8 mm insert on foam tape would stick out above the rim.

• 0.10 mm - for glue. It sits on the pocket floor with a snug gap.

• 0.15 mm - for glue, easier fit. Use it if 0.10 will not go in. On our TPU print 0.15 was loose, so it needs glue.

Left and right ears are mirror shapes, so print one of each. "Left" and "right" follow the STL, so if a piece will not go into one ear, try the other.

Suggested print settings

The files are already oriented face down: the visible face lies on the bed, and a textured PEI sheet gives it a clean matte finish. No supports, no brim.

I use a Bambu Lab P1S with a 0.4 mm nozzle: 0.16 mm layers, 3 walls, 100 % infill (a flat glue face with no bridges) and elephant foot compensation of 0.15 mm. A pair of 2.0 mm inserts takes a few minutes.

Mounting the inserts with glue or foam tape

Foam tape (gap 0.00, 2.0 mm): cut a piece of double-sided foam tape a little smaller than the insert, stick it on the back and press the insert into the pocket.

Glue (gap 0.10 or 0.15): use a gel super glue, ideally a flexible one (for example Loctite Power Flex Gel). Thin CA wicks into TPU and turns brittle. One drop on the pocket floor is enough.

What is tested

I have printed and fitted only the 2.0 mm inserts with the 0.15 mm gap, and that is the one that came out loose. The other variants use the same geometry with the numbers changed. A pure press fit without tape or glue is not tested.

About the images

The first gallery photos show the real printed inserts on a real band. The other pictures here and the animation are Blender renders of the included STL files and the band STL, including real cuts through the ear.

Credit and license

Remix of Capra Headband V3 by its original author, licensed CC BY-NC-SA 4.0. The inserts were modelled from its cat-ears TPU band STL. They are shared under the same license, CC BY-NC-SA 4.0: non-commercial use only, and remixes must use the same license.

This is an unofficial add-on, not affiliated with or endorsed by the original author.

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