deskthority

I recently bought a Model F Bigfoot keyboard and it was in its original state. Fundamentally it was in great shape, with two caveats - it had a disintegrated foam and a lot of dirt did accumulate.
After some work, this is the result after the restoration: The conversion to a xwhatsit controller requires a Beamspring controller without the edge connector and not the usual Model F one. The sensing PCB arranged in a 23 x 4 matrix - very similar to many beam spring boards. I used a SMD Universal Controller rev. 1.3: The Sensing PCB needs to be adjusted, as the controller is integrated into it. I removed all components from the Sensing PCB Controller (original controller) and cut the traces using a microscope before attaching the new xwhatsit: After that, I used individual wires and soldered them to the sensing PCB on one end and to the beam spring controller on the other. There are some wires that have to be left out, but in general a very simple process hooking up the rows and columns accordingly. In pandrew's QMK sources is a short readme that also gives some advices - the universal beam spring controller has the exact wiring (GND, ROW, COL) in its sources. Hope this is of interest and more of the Bigfoots find a new home. I think these are great keyboards and the wrist rest is something I do like a lot.

Removing all components that dont need any more is what I never thought, but seems not bad.

Has been quite awhile to see such project, good job.

John Doe wrote: 03 Jul 2021, 10:56 Removing all components that dont need any more is what I never thought, but seems not bad.

Has been quite awhile to see such project, good job.

Corrected my initial post - I had to remove the active and passive components from the original controller built into the PCB before attaching the xwhatsit.
It wouldn't actually be required, because I also cut all traces to them, but as I had to remove the old solder tin anyway, I used my solder pump and removed everything.

Pandrew helped me finding a last issue as well, which was caused by a line in the QMK code that had to be adjusted. I am always blown away that he built all the code just from pictures of the sensing PCB alone. I was sitting there for an hour or so and following traces with my PCB in front of me including a microscope for the soldering process and correct rows and columns. After I flashed the firmware - nearly all was working out of the box.

Bigfoot: A keyboard I can only recommend. The one I restored has now 3mm neoprene foam in it and I had a super hard time to close the sandwich again (if someone wants to repeat, use 1.5mm or 2mm). Had to use 5 clamps with each having a force of 100N... Couldn't take photos of that experience . With the Space Bar assembly trick to hold down the flipper with fishing line, doesn't make it easier. I recommend 4 arms and hands ...

Here's another picture of the cut traces: And here the wiring on the sensing PCB:

If anyone wants to replicate, find attached the QMK adjustments I made in keyboard.c: Additionally, here is the foam template for the Bigfoot: The cleaning of the keycaps and barrels have been done using an ultrasonic cleaner and then dried over 3 to 4 days so they were bone dry.
The cleaning of the barrel plate was done by first brushing off the debris and then spraying vinegar on it which was rubbed in with a toothbrush.
The top case was soaked in a a mixture of warm water and laundry detergent including the feet. With some scrubbing and rinsing with pure water it was clean again.