Two plates.
One removable lighting layer.

The upper plate holds the switches. The lower tray contains six light compartments and four rigid screw posts. Your existing M3 × 8 mm screws thread into brass heat-set inserts in the tops of the posts. No flexible clips or glue hold the tray.

See how the layers fit

Drag to rotate; scroll to zoom. Move the slider to separate the layers. Click a part to identify it.

Blue: upper plate · dark gray: lower baffle tray · black: existing screws · gold: heat-set inserts.

Actual exported CAD geometry. Electronics and wires are omitted here for clarity. The slider illustrates separation; inserts are installed permanently in the lower tray. Support the tray when undoing its screws from above.

What changes?

• New upper plate: unchanged from baffle-tray-v2. Reuse its upper sample or full upper plate if you already printed it. Older plates without the four tray holes are different.
• One lower tray: all six cups are joined by a floor. Four solid posts now have blind heat-set pilots instead of through-holes for nuts.
• Existing case: retained. Do not drill your old top plate freehand; print the matching candidate plate after testing.
• Four visible screw heads: at the outer edges of the key area. They sit above the top surface rather than in countersinks.

Use your existing hardware

Use spare pieces from your existing packs. The sample screws can be reused; its two embedded inserts stay in the sample. The full keyboard uses ten inserts (four case, two foot, four tray), plus two for this test. No new hardware type, M3 × 20 screws or loose tray nuts are required. Keep the original case fasteners in place.

Use a 2.5 mm hex key and a suitable heat-set installation tip on your soldering iron. Exact insertion temperature depends on the filament and tool. Adafruit recommends an insert tip to keep the insert straight. Confirm the screws measure 8 mm under the head, and your inserts match the listed dimensions before heating.

Print settings

• Lower tray: black PETG. An opaque material helps block light. Bottom flat on bed, compartments up, supports off.
• Upper sample: white or clear PETG. Supplied visible-face-down orientation; switch retaining recesses face up, supports off.
• Both samples: 100% scale, 0.4 mm nozzle, 0.15 mm layers, four walls, 100% infill. Inspect thin walls and complete screw-hole paths in the slicer.
• Full upper plate is oriented differently: underside on the bed, raised joystick seats up. Review the shallow underside switch recesses; local support may be needed depending on your printer. Avoid filling holes with support.

Try the small sample

1. Disconnect USB and leave electronics out. Print one lower sample; reuse the v2 upper sample or print the included upper STL. Clear strings. The upper holes should freely pass an M3 screw.
2. Install two inserts in the lower sample. Set the tray flat, cups up. The larger holes in the tops of the two posts are 3.9 mm starting pilots. Place an insert over each pilot and use a suitable heated insertion tip to press it straight down, slowly, until its top is flush with the post. Let the heat soften the plastic; do not force a cold insert in. Stop if the post distorts or the insert tilts.
3. Let both inserts cool fully. Do not insert a screw while the brass is hot. Check that the insert is flush, straight and does not spin. Its grip in your actual PETG is the main new fit test.
4. Join the empty layers. Cup openings face the underside of the upper sample. Insert two existing M3 × 8 mm screws from above and finger-start them into the inserts. Tighten gently until seated; no wrench or loose nut is needed underneath. Stop if a screw binds or an insert rotates.
5. Check real switches and keycaps. Both switches should latch from above and move freely. The tray should not rock. Undo the screws while supporting the tray and lower it to expose the solder pins.
6. Dry-fit the LEDs. Pockets locate the LED boards but do not clamp them. Use thin removable electrically insulating adhesive underneath, no more than 0.2 mm total allowance. Keep light-emitting faces clear. The modeled gap between LED top and switch-pin envelope is 0.8 mm; actual solder and insulation must also clear.
7. Leave wire slack. LED leads pass through floor slots and switch/diode leads through upper wall notches. Allow the tray to lower about 20 mm without pulling a solder joint. After checking the electrical connections, test one light for leakage before wiring all six.

Send a side photo with the layers joined and tell me whether the inserts sit flush, the screws tighten gently, and the tray stays steady. Do not print the full lower tray until the sample passes. Heat-set pullout strength, repeated use and light isolation remain unverified.

Full-size files — wait for the sample

These two parts form the finished pair. The upper plate is unchanged from v2; only the lower tray needs replacement if you already printed that version. The full tray is stepped around the six lit keys so it leaves room for the encoder, joystick and other wiring.

Upper plate STL — WAIT · Upper STEP
Lower tray STL — WAIT · Lower STEP

Complete CAD/source kit · Assembly STEP — view only · CAD checks · Technical notes

Collision checks cover the modeled case, installed inserts, screw engagement, switch/pin and electronics envelopes. They do not prove real-world fit, printer tolerances, wiring access, optical performance or lifetime. The main site's older full-keyboard animation still shows individual adhesive cups.