Minimal Hard Case for Bose QuietComfort Ultra 2

Slim snap-shut hard case for Bose QC Ultra headphones

A minimal pill-shaped case that’s just big enough for the folded headphones, made to slip into a small travel bag. The lid slides over a lip and clicks shut. Nothing sticks out: no hinge, no latch. A small notch at each end gives a fingernail something to push against when opening it.

Designed around the Bose QuietComfort Ultra (2nd gen), folded.

Size

• Outside, closed: 135 × 187 × 50 mm

• Inside: 133 × 185 mm at mid-height, about 122 × 174 mm at the floor, 47.6 mm deep

• Tightest point (the lip): 130.7 × 182.7 mm

• Weight: about 103 g in PETG (base about 51 g, lid about 52 g)

Check the fit first
Print qcu_pill_test_ring_base.stl (about 10 g) and lower it over your folded headphones. If they pass through the ring, they’ll fit the case. Print the lid ring as well to test the click with your filament before printing the full case.

Print settings

• Material: PETG recommended. It flexes for the click and copes with a hot car or bag. PLA works, but the click is stiffer and can wear.

• Layer height: 0.2 mm

• Walls: 3 or more at 0.4 mm line width. The 1.2 mm walls should be solid perimeters with no infill.

• Supports: off. Everything prints without them.

• Seam: Back. On the base and lid it lands on a curved end, away from the click on the long sides.

• Brim: none. It would leave a lip on the curved bottom edge.

• Fuzzy skin: off. It spoils the fit of the lip.

• X-Y hole and contour compensation: 0

• Calibrate flow for your filament. Over-extrusion eats the 0.15 mm clearance.

• The parts are already oriented: base floor-down, lid top-down. Each piece needs a bed of about 140 × 190 mm, so print one per plate.

Changes from the original

• Normal printing, not vase mode. Solid 1.2 mm walls (3 perimeters) and a 1.2 mm floor, so it’s stiffer and prints with a standard profile.

• Smaller. Sized for the Bose QC Ultra folded: 133 × 185 mm inside at mid-height, 135 × 187 × 50 mm outside when closed. The original is 150 × 200 × 50 mm.

• The lid slides on. The lip has 0.15 mm clearance per side and a chamfer at the top edge, so the lid fits when printed with normal walls. The original’s zero-clearance lip only works as a single vase-mode line.

• It clicks shut. A bead inside the lid rim clicks into a groove on the lip along both long sides. Nothing sticks out.

• Nail notches. A small notch in the lid rim at each end gives you something to push against when opening it.

• No supports. A ledge with a 45° underside joins the lip to the wall, so every part prints without supports.

• Kept from the original: the pill shape, the curved bottom edge, the 30 mm halves and the 10 mm overlap.

Resize it for other headphones
The Python script that generates the case is included as qcu_case_v3.py. Change the numbers at the top and rerun it:

• IN_W and IN_L: inside width and length at mid-height

• BEAD_H and GROOVE_D: click strength. Change them in 0.1 mm steps.

• LIP_CLEAR: lid fit

• NOTCH_W and NOTCH_D: size of the nail notches

To run it with uv:
uv run --no-project --with manifold3d --with numpy python qcu_case_v3.py out

Or with pip:
pip install manifold3d numpy, then python qcu_case_v3.py out

Files

• qcu_pill_base.stl, qcu_pill_lid.stl: the case

• qcu_pill_test_ring_base.stl, qcu_pill_test_ring_lid.stl: fit and click test rings

• qcu_case_v3.py: the generator

Generated with assistance from Claude