EVQWJN007 trackball guide: resurfacing, 5.5 mm ball, TPU shim
beams' guide revives dead trackballs by roughing the ball on 120-grit paper or fitting a 5.5 mm glass ball, with a printed shim to stop the module rattling.
What it takes
- Disassembly
- 3D print
Difficulty 2 of 3 — moderate.
Details
Jing Dong (beams) got five dead-on-arrival EVQWJN007 modules working and wrote it up on jing.io. The main fix is mechanical: roll the ball on 120-grit sandpaper until it is visibly matte so the rollers grip again. The stock ball measures about 5.38–5.40 mm; a 5.5 mm glass, brass or steel ball adds inertia and tracks more smoothly. The guide separates type A modules (full metal cover), which do best with the resurfaced original ball, from type B (partial cover), which take the glass ball.
A TPU shim STL in the qmk-uconsole repo takes up the play between module and faceplate. Shuflie arrived at the same idea independently — a printed shim around the socket lip stopped the rattle and made tracking reliable at any angle, though quick flicks still lag behind the sensor.
Links
Open at Forum threadRelated mods
Swap the stock ball for a white BlackBerry ball, the ball from a Pimoroni breakout or a fresh EVQWJN007 module — the usual first fix for a jumpy trackball.
Open-source QMK port of the keyboard firmware: Select + ball scrolls, Fn + G game mode, precision mode, tap-hold keys and a web tester, flashed over USB.
A modified build of ClockworkPi's own Arduino firmware: QMK-like trackball smoothing and Select + ball scrolling without QMK's USB power quirks.
A clean rewrite of the stock keyboard firmware on STM32 HAL: ten switchable layers, a better trackball curve with inertia, Fn lock and auto-dimming backlight.
SuperMarioSF's xinput middle-button emulation turned the ball into a scroll wheel; ClockworkPi then built Fn + ball scrolling into the stock firmware.
One xinput line remaps the ball's middle-button click to a left click on X11; firmware or libinput hwdb rules do the same job elsewhere.