Realforce 21UB HiPro

In my search to find the last bit of HiPro paraphernalia I was missing for my HHKB, I saw a single image of a 23UB modded to use the standard HiPro 2u numpad keys. So I decided to go ahead and try it for myself.

A note about Topre housings. They’re not square. I could get the 2u housing to hold in the horizontal cutout via friction, but not the vertical cutout, as the cutouts are wider than they are tall. Had I known this, I would have left a bit of material on the vertical section to keep the housing more secure. It doesn’t move around under normal use, so not super concerned. May figure out a solution next time I take it apart.

Plate removed from 23UB.

A little dremel action to create two new 2u wide spots for housings I scavenged off an old board.

This photo illustrates the contact points for 17b and 12b. They’re 0 and + respectively. Convenient.

The screw between 12a and 11 no longer fits due to the 2u housing being in the way. Topre’s fascination with using a screw every centimeter means I’m not particular worried about it.

And the whole thing put together.

As is, the - key is actually =, and the dip switches on the back don’t change that behavior. So I’m using a hasu USB to USB converter to rectify that. Everything else works straight away.


Woah, looks amazing! I didn’t realize that the numpad PCB had options for 0 and + ; very good to know! Thank you for sharing!