Chyros: the best way to take the P70 keyboard apart is to just break all the plastic. The case is shit anyway, so there’s not much loss.
![Wink ;)](./images/smilies/icon_e_wink.gif)
You can then see how it’s not pure plastic holding everything together: there are also a couple of metal strips which provide a bit of rigidity lengthwise (though as you noted, do absolutely nothing to resist twisting). Finally, if you want something to swear at, try desoldering some of the switches. Each switch has 4 leads bent down flat against the circuit board’s pads; even with some practice and fancy tools, they still each take about 4x longer to desolder than an SKCM switch.
Note that when the plate spring snaps downward, you suddenly get a bit of extra slack in the coil spring, so the overall downstroke force curve is a bit of a sawtooth kind of shape, which is different from what you get with most other types of switches. You also get a big snap on the upstroke when the plate spring pops back to its original shape. (I was hoping you’d try to push the coil spring on top of your demo jar top.)
As for the keycaps, did you note the nice thick homing bar caps, and nice thick larger caps? It’s only the 1u caps and Alt/Ctrl caps which are ridiculously thin.
Have you tried measuring your typing speed / accuracy on this keyboard, or others? I find that while it’s not my favorite sound or tactile experience (they’re nice, but e.g. Model Fs seem more satisfying somehow), Alps plate spring is pretty much the fastest and most accurate keyswitch I’ve tried typing on. I think it’s a combination of nice medium stiffness, crisp tactile drop with associated sound, reliable actuation after the click, and the bounce on the upstroke.
One last note, I’m not sure these switches are as robust at retaining their original feel as some other types of switches. The plate spring seems like it can get worn out on some examples I’ve seen, though that might be from improper storage with the keys held down for years at a time. I don’t know how well they hold up to e.g. 5+ years of regular heavy typing. Worn out leaf springs can sometimes be restored by careful manual bending, but it’s hard to do with perfect consistency and there’s a chance of screwing up and wrecking it.
I’d love to see someone try to do a modern-day remake of these switches. All the patents are expired, and the switch construction is relatively simple and should be cheap at mass scale, though there are a decent number of tiny plastic pieces inside.