Case Cutouts Guide

Cutting the enclosure well takes one careful afternoon. Measure twice, cut once, and deburr everything.

The five openings

Opening	Size	Position
OLED window	Matches the display active area	Top face, centered
4 button holes	6-7 mm each (for 6x6 mm switches)	Below the display, evenly spaced
SMA hole	6.35 mm (1/4”) or the SMA flange	Side or top, away from the display
3.5 mm jack hole	6 mm	One side
USB access (optional)	Slot for the USB-C plug	Bottom or side

OLED window

• The 2.42” SSD1309 has a glass active area of about 55x27 mm. Cut the window slightly larger (58x30 mm) so the glass does not touch the plastic.
• Cut from the inside where possible, or use a template on the outside.
• Use a hobby knife for plastic (score and snap) or a rotary tool with a cutoff wheel. Sand the edges square.

Buttons

• 6x6 mm switches need 6.5-7 mm holes; a 7 mm drill bit is perfect.
• Space them at least 10 mm apart so fingers can hit them without pressing two at once.
• The switch caps should poke 1-2 mm above the case surface.

SMA

• The E22’s SMA connector is a panel-mount or a through-hole socket. If it is on the module, the case needs a hole aligned with it and the module must be positioned so the connector reaches the hole.
• Alternatively, use an SMA pigtail: mount the jack in the case, run a short cable to the module.

The golden rules

• Deburr every hole; plastic shavings inside a case find their way into the buttons.
• No sharp edges where wires run; add a rubber grommet for the SMA and jack if they pass through metal.
• Test-fit before final assembly: close the case, check the buttons travel, the display centers, and the antenna threads fully.

Waterproofing

Any cut hole is a water path. For IP-rated builds, cover the buttons with a membrane and seal the SMA with a rubber washer - see the waterproofing page.