Fujitsu Peerless clickiness

[chyros]

So I got a board today with Peerlesses in them at the recycling centre. I've been curious about them for a while, and now I got to test them out first hand! ^^

Thing is, these switches are supposedly clicky, but according to the DT wiki, no-one really knows how they achieve this clickiness. Well I have a theory. See below the four "stages" of a Peerless switch:



So essentially it's a plastic plunger over a spring housed in a "sock" on top of a rubber dome.

The wiki suggests that the clicky sound is made by a shockwave, but frankly I doubt that. At first, I thought it was pressure venting through the plastic "sock" - a bit like re-corking a bottle. But then I listened closer, and I noticed the sound vaguely resembled buckling springs - albeit much softer. That got me thinking, and I think I get it now. What happens is that the rubber dome underneath provides the tacility, and collapses at a certain pressure, at which point the sock with the spring in it accelerates downwards. Then, the travel is checked by the bottom of the switch, and the sock - and cylinder - are stopped quickly, which essentially gives the spring a little hit, causing it to ring like a buckling spring. The sound is rather muffled because of all the plastic of course, and I think the cork effect also slightly compounds it.

What do you guys think? I don't know how many of you have these switches, but I'm interested to see what other people think is going on.

[Daniel Beardsmore]

I took apart a Peerless switch, and observed the following:

• Good solid, sharp click when assembled (I made sure to choose a good specimen)
• With nothing but the spring and the dome, pressing on the spring (with an old Staedtler mechanical pencil) generates a distinct but comparatively quiet click sound
• Adding the plastic tube amplifies the click sound
• With the dome, spring, and slider, you get one of two outcomes: a perfectly linear switch (no click and no tactility) or a soft clicky switch: removing the plastic tube reduces the switch weight

To reassemble the switch without the plastic tube (per observation 4), put a tiny amount of Vaseline inside one end of the spring and secure that end of the spring to the nub inside the slider using the grease; I've never used the Vaseline trick before, and it's amazingly effective.

This is a strange switch, and it's amazing to discover that the spring can completely nullify the tactility inherent in rubber domes. The interaction between the dome and spring is quite unexpected.

Removing the tube changes the feel from "Model M" (long linear pretravel, heavy feel) to "MX Brown" (medium pretravel, soft tactility). The resulting feel isn't guaranteed to fit the two extremes: one attempt got me marginal tactility on an otherwise silent linear switch. You do also get far less of a click though this depends, as one reassembly attempt yielded a soft, smooth feel with a good click. Removing the tube randomises the feel and sound.

Of course, I've now lost one tube and one spring inside the keyboard somewhere, and I found the slider where the nub broke off (left on the ` key since I seldom use it).

The keyboard isn't connected, so I didn't test the effect that this has on actuation.

In terms of chyros's question: the click only requires the dome and the spring. The click does not require typing force, nor does it require bottoming out: you can get a click from slowly pushing the key past the tactile point, and if you remove the tube, the tactile point occurs higher up. It still seems to be something to do with a shockwave in the spring as it's suddenly allowed to expand.

Reference keyboard: FKB4700 105-key ISO unbranded.

[chyros]

Interesting, I hadn't thought of leaving out the tube yet. Cool idea. I've tried it myself - I can hear a tiny click when using a propelling pencil, but I absolutely can't hear a damn thing with the slider on. Maybe the keytravel isn't enough to make it collapse enough, or it's too muffled. This is on an Epsom Q203A. They are completely linear without the tubes.

These are definitely among the more strange switches I've tried so far. They feel very obviously like rubber domes, but at the same time, I can see where you're coming from with "buckling spring feel", and they even somewhat sound like them. I can see why some people would really like these - and why many others would hate them xD . I might take this board to work if my colleagues complain about my (much louder) Dell AT101W (ironically, replacing a tactile board with a clicky one). I accidentally warped the spacebar with hot water while cleaning the caps though .

The fact it's clicky even when you don't bottom out was definitely a giveaway for me too, that's why I suspected it's the spring accelerating and getting stopped quickly that made the sound - a bit like MX blues, except the "hammer" is the spring itself rather than a plastic jacket. Does that sound reasonable?

[Daniel Beardsmore]

It would be interesting to record it and play it back in slow motion (one of those super slow motion cameras, but one that records sound) and see exactly what does happen.

[chyros]

Indeed. A cut-out of the switch would be quite useful, too .

I might disassemble this Epsom someday and make a cut-out of it, actually. The spacebar is mullered and there's something with the stabilised keys - they are atrocious xD . Shame, cause the rest of the keyboard is actually fairly interesting...

Will have to make another video review before I kill it, though xD .

[MKB]

So I got a board today with Peerlesses in them at the recycling centre. I've been curious about them for a while, and now I got to test them out first hand! ^^

Thing is, these switches are supposedly clicky, but according to the DT wiki, no-one really knows how they achieve this clickiness. Well I have a theory. See below the four "stages" of a Peerless switch:

Show Image

So essentially it's a plastic plunger over a spring housed in a "sock" on top of a rubber dome.

The wiki suggests that the clicky sound is made by a shockwave, but frankly I doubt that. At first, I thought it was pressure venting through the plastic "sock" - a bit like re-corking a bottle. But then I listened closer, and I noticed the sound vaguely resembled buckling springs - albeit much softer. That got me thinking, and I think I get it now. What happens is that the rubber dome underneath provides the tacility, and collapses at a certain pressure, at which point the sock with the spring in it accelerates downwards. Then, the travel is checked by the bottom of the switch, and the sock - and cylinder - are stopped quickly, which essentially gives the spring a little hit, causing it to ring like a buckling spring. The sound is rather muffled because of all the plastic of course, and I think the cork effect also slightly compounds it.

What do you guys think? I don't know how many of you have these switches, but I'm interested to see what other people think is going on.

I have had several of these.  I no longer have one but they are very nice.  I wish they were still made.  The last one I bought out of Canada.