IBM Model M Keyboard Bolt Modification (Rivet Replacement / Restoration)
I bolt-and-nut-modify a badly deriveted 1986 IBM Model M 1390120 keyboard to make it work again. This video is not riveting! That's a pun.
Note: see my "redux" video after watching this one for a recap of the mistakes I made while doing this one: • Model M Keyboard Bolt Modification (Redux)
I gained a new respect for the engineering that went into this design after doing this. Above and beyond the famed buckling spring mechanism:
it is dead-easy to disassemble and clean.
most of the actual engineering genius is in the barrel plate design. the way it's designed makes the rest of the keyboard stupid simple. there are surprisingly few parts to make the keyboard work, and, other than the barrel plate itself, the parts are all human-repairable.
you can't reassemble it incorrectly if you don't separate the baseplate from the barrel plate; it's literally impossible; the few parts that make it up only go together one way.
even when you do separate the baseplate from the barrel plate, it's still difficult to reassemble it incorrectly; it still only goes together one way. the worst you can do is knock the hammers out of alignment while you remarry the baseplate to the barrel plate, put one in the wrong hole, forget a hammer, or bend a spring.
the spring mechanism and membrane design is incredibly reliable and robust; even when apes take it apart and put it back together again, the hammer contact continues to work.
You might call it overengineering. I call it beautiful.
It's a 1/16" drill bit.
7/32" nut driver: https://www.amazon.com/Wiha-26556-Pre...
I didn't mention it in the video, but it's also useful to have a 4mm nut driver to put the nuts on the bolts instead of an adjustable wrench: https://www.amazon.com/gp/product/B00...
Bolts: https://www.amazon.com/gp/product/B00...
Nuts: https://www.amazon.com/gp/product/B07...
Unicomp sells new Model Ms and parts: http://pckeyboard.com
Props to AkBKukU for his Wheelwriter bolt mod video, from which various ideas were stolen: • 0x0025 - Bolt Modding an IBM Wheel Writer 3
Lots of info was gleaned from the Geekhack keyboard enthusiasts' forum: https://geekhack.org/index.php
Note that I later did try to plastic weld the barrel plate assembly together again. It went poorly. The weld goop works as advertised but the joint was just too weakened to make it feasible to handle the barrel plate roughly afterwards; I tried to fit it onto another base plate with keys and all later but it ended up breaking again while screwing the nuts down. I used the barrel plate from a donor unit I use for parts. But even if I hadn't had the donor unit, I would have been able to get another: Unicomp sells replacement barrel plates (even for Space Saving keyboards!)
I plan to start selling off my keyboard collection, see https://www.ebay.com/usr/chrism714d to see if I've got anything currently for sale