Alps SKCLKB and double action switches

[Daniel Beardsmore]

Photos from Parak and Daemon Raccoon in the links/references:

[wiki]Alps SKCLKB[/wiki]

(If we're lucky, Daemon Raccoon may treat us to full disassembly shots of this bizarre switch and the even more staggeringly peculiar one found on the enter, backspace and space bar of that Canon typewriter.)

The term "double action" comes from Sandy, based on his secret ninja Alps 1994 catalogue that us mere mortals may not set our eyes upon (maybe Sandy alone has the eyes that can stare directly into the Alps Vortex itself).

I don't know enough about these switches (of which HaaTa has virtually a monopoly) so I'm using Alps's term to describe them for now.

Provisional page on this category of switches, with a summary of my understanding, from discussions with HaaTa:

[wiki]Double action switch[/wiki]

(I don't have any of these switches myself, but it did need to be written up.)

[webwit]

Sounds like a Datahand thumb down key.

Example: First action of left thumb down key is Shift. Second is Caps Lock.

[Daemon Raccoon]

I've got a soldering iron in the mail thanks to HaaTa, once that's here I'll desolder them and get some shots.

[Daniel Beardsmore]

Sounds like a Datahand thumb down key.

Example: First action of left thumb down key is Shift. Second is Caps Lock.

Interesting, didn't know this idea had survived as recently as the Datahand.

What's the difference in force between the two stages?

Needs pics :)

[webwit]

Not sure about the force, a standard Datahand key is rated as 18-22g. The first stage very little force, it's only a matter of travel. Then there's a very light tactile bump for the second stage, and there's a light click if you press through the bump.



I think there was a guy who posted who deconstructed a thumb unit... haven't found it yet. It's probably like all the other keys a combination magnet/optical switch, but now with two sensors in the key travel path instead of one.

[Daniel Beardsmore]

I was as surprised as Sandy with the stage two rating of the SKCLKB. I have a couple of superstiffy 280 g switches from Hua-Jie Tai-Hao (taken from a custom order) and I thought those were extreme, but 500 g? It would be interesting to experience pressing hard enough on that to activate stage two.

With the DataHand, though, it sounds like the opposite should be true — what stops you from getting shift lock instead of shift? Just careful practice? I guess since you're not striking keys, it might be easier to exert less pressure.

[Edit: Wrong mfr for 280 g switches]

[webwit]

Yes, those light switches wouldn't work on a normal keyboard. But your thumb is already resting there. Just apply a little pressure for shift, and you rest on the tactile bumb. Then apply more pressure for the second action. At the beginning I applied too much pressure sometimes to start with and activated the second action by accident. All in all one needs to learn to relax on a Datahand and just tap keys instead of all the action you put into a standard keyboard.

[dorkvader]

The selectric typewriters have double action switches to cover typematic functionality. If you dont have a selectric, I can take some pictures of mine.

Basically, as you press down, the key (typebar) hits a small plate. After that point, the secondary action (repeat) engages and more force is required.

I just tried it and I don't think it's 490 grams though.

[Daniel Beardsmore]

I don't have one, no. Interesting though that this idea may goes back to electromechanical switching, i.e. double-action switches appear to be copying another aspect of the Selectric.