PCB Sockets for mechanical keyswitches

User avatar
Julle

29 Dec 2014, 22:32

I thought I'd regurgitate this still-born idea I've chewed on for the past couple of days.

While desoldering and soldering 88 switches for the n-th time in the last year, I started thinking about sockets for mechanical switches. Sockets that you solder instead of the switch itself. You would just plug the switch inside the socket through a mounting plate. The socket should have a plastic base that covers the entire switch footprint plus all the required holes and divots to accommodate a Cherry MX switch for increased stability. Also, there could be a MX PCB -> Alps switch adapted socket.and vice versa.

The idea is you could just buy the sockets and solder them on any of your existing keyboards. This has probably been thought of before but a quick search on DT returned nothing. I mean, if pretty much any other electronic component is can be plugged to a socket, why not a keyswitch?

To compensate for the added height, you’d add a second plate on top the existing plate or install a thicker plate altogether. Alternatively, there could be a small bezel piece to install on the switch itself for stability but that’s another fiddly little piece to manufacture and I don’t want that.

Pros:
  • Easily replaceable switches
  • Possibilities for mixing switches: Alps switches on a MX board with an adapter socket and vice versa
  • No soldering - no additional wear and tear on PCB traces
Cons:
  • Added height: this could be reduced by clipping original switch leads a little.
  • Switch stability: probably compensated with an additional plate (acrylic, aluminium, steel, PVC?)
  • Switching keycaps becomes more difficult as switches may come off in the process (this may also be an advantage e. g. when replacing Alps caps)
Challenges
  • Fiddly things to manufacture
  • Prototyping - are there pre-made parts (e. g. socket leads)?
  • Long-term testing
  • Socket longevity: how many plugs and unplugs would they last?
I need your input on this matter. Has anyone ever tried this?

User avatar
Muirium
µ

29 Dec 2014, 22:40

Don't forget stabs. If the switches ride higher, the stabs need to shift up, too.

I like the idea overall, though. Especially for pre-existing keyboards, and as a way to introduce Matias switches in MX boards. But I've got a nagging sensation it's not really doable. Don't know though.

shamanas

30 Dec 2014, 13:19

thesupergeek42 over on /r/mk wanted to try this out and had ordered a couple of sizes for tests, dunno if he was successful though :/

User avatar
HzFaq

30 Dec 2014, 14:11

There is a thread on GH about a board that has hot swappable leds and switches called the Smart 68. I think the GB has just finished in China and there is also talk of getting it on Massdrop.

https://geekhack.org/index.php?topic=61714.0

User avatar
Julle

30 Dec 2014, 21:08

Thanks for the input. As cool as the hot swap board on GH is, I'm lookin to do something that benefits existing boards.
But like Muirium pointed out, stabilizers are going to pose a problem.

User avatar
Julle

30 Dec 2014, 21:40

Those ferrules used in the GH project would be ideal. I need to find out where they sourced them.

JBert

30 Dec 2014, 23:24

I've seen somebody post that they simply buy a bunch of DIP sockets with round holes:
dip-socket.jpg
dip-socket.jpg (97.35 KiB) Viewed 4474 times
The trick is then to weaken the plastic until the metal bits come out.

User avatar
PJE

04 Jan 2015, 02:08

You may also be able to use individual pin socket inserts embedded in the PCB. These sockets can sit flush with the PCB depending on they style chosen.
Attachments
uploadfromtaptalk1420333636488.jpg
uploadfromtaptalk1420333636488.jpg (16.9 KiB) Viewed 4404 times

shamanas

08 Jan 2015, 10:05

Those should actually do (I had them bookmarked from a while ago, one of the sizes should be really similar to the pin of a Cherry MX switch) :)

User avatar
chzel

08 Jan 2015, 10:34

Those are vias, essentially rivets to connect the two sides of the pcb. They will not work because the have no springiness to maintain contact.

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