I'm a long-time Model M fan and only recently found out about the existence of legendary beam spring switches. Well, one thing led to another; and after hundreds of hours and way too much money for even a "parts"-quality board, I have a thoroughly restored and converted 1983 beam spring keyboard as my "new" daily driver.
The keyboard itself is a behemoth, certainly earning its "white whale" moniker. I really like how it looks too. With a wrist rest, the massive height and typing angle don't bother me; and the Displaywriter layout is close enough to a modern one that it can easily be remapped. It doesn't have a solenoid like some contemporary beam spring boards have, but it does have a built-in speaker coil which augments the already-nice sound in a way that complements rather than overpowers it.
But of course, on a keyboard like this, the real star of the show is the switches: Genuine IBM beam springs. There's a lot of hype around these, and it's probably impossible to separate personal biases out after spending so much time on the project; but I'll do my best to describe them.
This is my first experience with beam spring switches; and the main point of putting this much effort into the restoration was to feel what all the hype was about without wondering if it was compromised from nearly a half-century of degradation or contamination. After typing on it for a few days, what I can say is - it was worth it.
The clicky tactility is just perfect, and the travel is so smooth it almost feels like the keys are floating. The slider's behavior is governed by three individual springs at the top and bottom which help to stabilize and center the slider, with no off-center ramp, click leaf, bar, etc. The mechanism seems to minimize lateral forces on the slider, and the unusually long bearing surfaces (from the switch's absurd height) further reduce rubbing. I suspect this has a lot to do with the incredible smoothness.
The tactility, click, and actuation all come from the same mechanism and are all perfectly synchronized. They're also entirely axial, sending feedback straight through the stem. I think this is what leads to it feeling so sharp and clean without feeling overly aggressive.
The biggest problem with these switches is that, after using them for a while, it's going to be so hard to go back to anything else. And I'm not sure I can afford a whole second restoration project to have one at work too!
The restoration project itself has been quite an effort. I had some idea of what I was getting into; but it wasn't until after I unboxed it that I found the extent of the damage that would need to be repaired. This extremely heavy keyboard was clearly dropped from a height, possibly down stairs or something; I don't know. But the steel frames were badly bent, the case was cracked, and a number of switches were directly impacted, shattering some of the internal components. And of course all the age-related degradation from being over 4 decades old.
Ultimately, I was able to repair essentially all faults, returning 83 of the original 84 switches to working condition. I also spent quite a lot of time measuring and cataloging each switch's behavior to prioritize the top-performing switches on the most-used keys. And of course, converted it to USB with n-key-rollover for modern compatibility and key remapping.
For anyone interested, I posted a detailed write-up of the restoration project, including lots more pictures, on GitHub. I also designed a number of 3d-printable tools to help with the project, now available on Printables. And would be happy to answer any questions here!
Full restoration write-up with lots of pictures: https://github.com/CrispyConductor/display_writer_restoration/blob/master/report/index.md
