typewriter/hardware/case

Enclosure — typewriter body (concept)

Part of Typoena — the distraction-free DIY writing machine. This page covers the enclosure only; the project root README covers the whole appliance (hardware, software stack, roadmap).

A 3D-printable case for Typoena. The e-paper strip sits on a reclined deck where a typewriter's sheet of paper would be; the keyboard you bring rests in front. There is no platen part (it complicates the print) — the rounded back-top edge is a subtle roll that nods to one for free.

Status: v0 concept, not yet printed. Outer form and the screen-retention / board-mounting strategy are worked out and render cleanly. Board hole positions and port offsets are placeholders marked << MEASURE >> in the .scad — confirm them against the real board before printing a final.

Files

File	What
typoena-case.scad	The parametric model. All dimensions live at the top.
concept.html	Dimensioned side/front/top drawing (open in a browser).
renders/	PNG previews (regenerated by the commands below).

Render / preview

Needs OpenSCAD. Open typoena-case.scad in the GUI and flip the show variable, or from the CLI:

cd hardware/case
# assembled, coloured, screen ghosted in
openscad -o renders/assembled.png --imgsize=1100,825 --colorscheme=Tomorrow \
  --camera=0,0,0,62,0,22,0 --viewall --autocenter \
  -D 'show="assembled"' typoena-case.scad

# export a printable part to STL (body | bracket | baseplate)
openscad -o body.stl -D 'show="body"' typoena-case.scad

show accepts assembled · body · bracket · baseplate · print_plate.

Dimensions

From the datasheets, baked into the model:

• Panel — GDEY0579T93: glass outline 150.92 × 56.94 × 1.0 mm, active area 139.00 × 47.74 mm, pitch 0.1755 mm. Strip aspect ~2.9:1.
• Board — ESP32-S3-DevKitC-1: ~70 × 28 mm, USB-C ×2 + reset/boot on one short edge (that edge faces the back wall).
• Body (default): 176 W × 104 D, 24 mm front → 58 mm back, deck reclined ~21°. Walls 2.4 mm, deck 2.6 mm, corner radius 8 mm.

The deck angle is the one knob worth tuning first — see below.

How the hardware goes in — glueless

The whole design avoids glue on the fragile 1 mm glass and keeps every part serviceable.

Screen (bezel lip + foam + screwed bracket)

 front face                     the sandwich, front → back:
 ┌───────────────┐              1. deck BEZEL LIP  (overlaps ~4–5 mm of the
 │  ┌─────────┐  │                 glass's inactive border only, never the
 │  │ active  │  │ ← lip           active area — lip_t = 1.4 mm of material)
 │  └─────────┘  │              2. GLASS drops into the recess from behind;
 └───────────────┘                 the recess walls locate it in X/Y
                                 3. FOAM gasket (non-adhesive closed-cell,
   [lip][glass][foam][bracket]      foam_t ≈ 1 mm) spreads the clamp load
        ↑ screwed to 4 bosses       so you never point-crack the glass
                                 4. printed BRACKET, screwed to 4 bosses,
                                    presses the stack forward

• The through-aperture is a hair larger than the active area and stays inside the glass-minus-lip envelope, so the lip covers only dead border.
• The recess opens straight into the cavity, and an FPC slot on the up-slope edge lets the ribbon fold back to the DESPI-C579 breakout.
• Foam does three jobs: cushions the glass, takes up print tolerance (±0.2–0.5 mm), and removes any need for adhesive. Cut it from a plain EVA/ PORON sheet — no sticky backing.
• Alternative if you want no screws: replace the bracket with printed cantilever clips. It works, but clips point-load the glass edge; the foam+bracket route is gentler and I'd default to it.

Boards (the baseplate is the chassis)

Mount everything to the baseplate on the bench, then drop it in and close from below — far easier than fishing screws inside a shell.

• ESP32 + DESPI-C579 sit on printed standoffs (M2.5 self-tap). Positions in esp_holes / brk_holes are placeholders — set them to your board's holes. No mounting holes on your board rev? Switch to slide-in edge rails.
• The baseplate screws up into 4 corner posts in the shell.
• A cable relief notch at the back lets the keyboard's USB-C cable exit and route around to the front.

Assembly order

1. Lay glass into the deck recess (from inside), add the foam gasket, screw the bracket down onto the 4 bosses.
2. Screw ESP32 + breakout to the baseplate standoffs.
3. Connect the FPC (screen → breakout) through the slot.
4. Screw the baseplate up into the corner posts.

Tune first

• Hb (back height) → deck angle. 18–22° is typewriter-shallow; raise Hb toward ~28–35° if the screen reads too edge-on when you're sitting close.
• << MEASURE >> items: esp_holes, brk_holes, port_x, port_z, screen_off (the real panel's active area is offset toward the FPC edge).

Print notes

• Material: PLA/PETG. Print the body in matte indigo (#130f40), the bracket/base in cream or brass — two-tone reads unmistakably "typewriter" for the price of a filament swap.
• Make the engrave read: on a body this dark the recessed TYPOENA is near-invisible until you give it contrast — a swipe of paint pen in the recess, or a 3–4 layer filament swap across the nameplate band mid-print.
• Shell, not solid: 2.4 mm walls + open bottom keep material low despite the chunky body form.
• Orientation: body deck-up (or on its back) needs little/no support; the bezel lip is a small overhang. Bracket and baseplate print flat.

Nameplate font

The TYPOENA engrave on the deck (recessed, faces the user) is set via the name_font parameter. Current pick: Monaspace Krypton (GitHub's mechanical mono). OpenSCAD only renders fonts installed on the system:

# current: Monaspace Krypton (installs the whole family)
brew install --cask font-monaspace

# alternative tried: Cutive Mono (typewriter slab-serif)
curl -sL -o ~/Library/Fonts/CutiveMono-Regular.ttf \
  https://github.com/google/fonts/raw/main/ofl/cutivemono/CutiveMono-Regular.ttf

fc-cache -f    # so the OpenSCAD CLI picks either up

To audition other faces: Google Fonts, filtered to monospace and previewing the name — https://fonts.google.com/?preview.text=TYPOENA%0ATypoena%0Atypoena&categoryFilters=Appearance:%2FMonospace%2FMonospace

Open questions / TODO

• Confirm the GDEY0579T93 active-area offset and which edge the FPC exits; adjust screen_off / the FPC slot.
• Real ESP32-S3-DevKitC-1 mounting-hole + port coordinates.
• Optional hinged lid over the deck (portable-typewriter-case echo, protects the glass in a bag) — docs/hardware.md calls for one; not yet modelled.
• Decide feet: printed (modelled) vs. stick-on rubber bumpers.