Delta Split 75

Fork/mirror of the DeltaSplit75 V2 open-source keyboard: case DXF/DWG files, PCB gerbers, and 3D model. Reorganized for local iteration and fab prep.

What this is

DeltaSplit 75 is a dual-mode 75% keyboard:

1. One-piece mode — left + right plates butt-join into a single unibody case; all keys present.
2. Spread-split mode — same PCB/plates but mounted in two separate shells with a physical gap between halves. At the seam there's a detachable switch that gets populated for one-piece mode and removed (or a blocker inserted) for spread mode.

The PCB is one ~322 × 120 mm board regardless of mode. Plates ship as left + right DXFs because the combined ~680 mm width exceeds most laser beds, and because the spread mode needs them as separate parts anyway.

Layout

case/
  bezel/        top bezel — Standard / Winkeyless / blocked-corner
  left/
    plate/      MX, ALPS, ALPS+MX, MX Costars
    middle/     5× stacked in one DXF
    bottom/
  right/
    plate/      MX, ALPS, ALPS+MX   (no Costars variant)
    middle/
    bottom/
pcb/
  gerbers/      KiCad 4.0.6 output, 11 files (Cu/Mask/Paste/SilkS/Edge.Cuts/drills)
docs/
  DeltaSplit-Final.step    3D assembly
  deltasplit.pdf           original build doc
  PCB_Dimension.dwg
  ORIGINAL_README.md
archive/
  *.zip, *.bak             source archives, AutoCAD backups

Stackup (top → bottom)

Designed for 3D printing or acrylic stack. Total height ≈ 25.5 mm.

Qty	Component	Notes
1	Top Bezel	3D print (one piece)
2	Switch Plates	Left + Right, 1.5mm Alu or 3D print
2	Mid Shells	Left + Right halves
2	Bottom Bases	Left + Right halves

Interconnect

• Original: TRRS (unsafe hot-plugging).
• Modern (RP2040 Build): USB-C to USB-C link.

3D print quantities (STLs in output/3d/)

Generated by scripts/case_to_stl.py — one STL per file, print the count listed.

STL	Prints	Notes
bezel_standard.stl / bezel_winkeyless.stl / bezel_blocked.stl	1	pick one variant
plate_left_<variant>.stl	1	pick one variant
plate_right_<variant>.stl	1	pick matching variant
middle_left.stl	5	STL contains one copy; source DXF had 5 stacked on sheet
middle_right.stl	5	same
bottom_left.stl	1
bottom_right.stl	1

Total: 1 bezel + 2 plates + 10 middles + 2 bottoms = 15 parts per keyboard.

Next

See PLATES.md for plate variant matrix, BUILD.md for fab-order guide, STATUS.md for current issues / TODOs.