21 Key Mechanical Numpad

A 21 key hand-wired mechanical numpad.

 

Designed to be used with a YD-RP2040 Raspberry Pi Pico, but I've included the STEP files if anyone wants to tweak it to hold a different microcontroller.

 

I'm personally running KMK firmware on it (there's a great tool called pog that makes it super easy to program your keyboard), but it can also be configured to run with QMK if you want.

Assembly:

For easier printing, I've made the case_top and the switch_plate separate pieces that fit snugly together.

The switches and stabilizers should click into the plate easily. Heat set inserts go into the four holes in the back of the case_top.

 

Since the Pico has more than enough pins, I just wired each switch directly to the board and daisy chained them all to a ground pin. I used double sided foam tape to secure the Pico to the case_bottom.

The case is then fastened together from the bottom with four M3 x 16 countersunk screws.

 

Boost MeIf you like this design, I'd appreciate the support :)