Keycap Replacement, B-Key Keyboard Atari 400

[wt808]

I have a B-Key keyboard that was missing a Shift key. I bought a couple of DSA-profile, deep-dish 1u MX keycaps to see if I could make them fit.

https://pimpmykeyboard.com/new-dsa-individual-keys/

I could not find an exact color match, so I tried a beige tone with black text (color GQN). These are sublimated keys, not doubleshot like the originals. The matte finish is a close match.

The new keycaps fit the switches, but sit slightly taller than the surrounding keys. The keycap stems differ by 0.125".

Here's the stem after milling:

Here are both keycaps installed and the keyboard reinstalled:

[_The Doctor__]

looks as though you could mill the surround a little and get it down a little further if you so desired, so long and the height you currently have doesn't interfere or have issues with travel, it could simply be considered a finished work.

 

Nice job on all accounts. Thanks for sharing, this is the very helpful stuff we all need.

[wt808]

The plastic is soft and melty. If I dwell on the stem too long, it starts to twist. I ended up plunging about 10 thou at a time, lift and let cool for a few seconds and repeat. First key was a nail biter, and the second went much more quickly. For the skirt I would just run it over sandpaper on a flat surface and rotate the key while doing so. I think if I clamped it vertically and tried to mill half at a time, the end mill would bite and eject the keycap from the vise.

 

Here's the resulting side view. The Shift keys do not sit over the shell so there's no interference when the key is depressed. The original function keys bottom out on the shell. If replacing those keys, I'd probably just leave the stem alone and let the keycap sit 1/8 higher.