Hotswapping PSA: The Infinity keyboard does not need solder for Alps switches.

[E3E]

As I was building some knowledge and information for my current project board, an Eagle PCB I want to use for some Alps switches, I stumbled upon both a reddit thread and a post on LinusTechTips regarding hotswapping. I've learned a lot, and know how I'll add it to the Eagle when the time comes, but out of curiosity, I tried something on my Infinity keyboard.

I noticed during desoldering that the switches' legs all needed to be wiggled to break a tiny trace of solder that the desolder vacuum could not get. Why was this? Because the Alps contact pins are so wide, they actually touch the pads on the PCB. There is a lot of friction, meaning good contact.

So a lightbulb went off. Can I use Alps switches without soldering? I plugged in the PCB (a paint job muckup on the bent plate case caused me to desolder everything, so I had just a bare PCB at this point) and lo and behold it worked. Not just a fluke either. I tested several Alps switches on different switch positions, and they all worked flawlessly.

Coupled with the fact that Alps switches mount solidly in the plate, this should mean that you can use any Alps switches without needing to solder! I measured the legs at 1.23mm wide, just FYI.

Of course, people are quick to detract from something without having bothered trying it, so here's some videos.

Hotswapping in action on bare PCB:

feature=youtu.be

My long-winded video demonstration on this:

[neverused]

It's certainly a proof of concept, but I am sure that reliability would be extremely poor. You're using a friction joint on components not designed to resist that motion. Longer leads and something like a socket might make it better, but overall I can't see this being feasible for regular use.

[E3E]

It's certainly a proof of concept, but I am sure that reliability would be extremely poor. You're using a friction joint on components not designed to resist that motion. Longer leads and something like a socket might make it better, but overall I can't see this being feasible for regular use.

This is definitely true, you're right! It doesn't have clips like the receptacles I've ordered do. To use receptacles for any alps board, it's much more complicated than the methods detailed in these posts: http://linustechtips.com/main/topic/430702-custom-keyboard-hot-swapable-switch-build/ and https://www.reddit.com/r/MechanicalKeyboards/comments/3p2qir/modification_hot_swappable_switches_maybe/

In conversation with the guy on LTT, we've figured the only way to get sockets that are the proper width to accept the wider-than-Cherry-MX Alps pins would be to bore out the pin holes on the PCB to accept the larger socket. This is likely possible because the pads are wide enough for the holes to be widened a bit, and if not that, then the traces would just have to be soldered on. He had to bore out some contacts himself, so it is viable, just tedious.

There's no easy way to do it for Alps, which means that I will be doing a ton of drilling on the Eagle PCB to get things to fit.

I'll update this post after a while of using the solderless Infinity to report any findings. It might be more viable than you think! Or less viable than I think. We shall see! With boards like the Smart 68 doing this, as well as the example on LTT, I do think it is viable to do with the proper sockets at the very least.

[fohat.digs]

I have soldered and de-soldered quite a few Alps keyboards, and when I forget to solder one or more legs, the switch is all but certain to function erratically, if at all, in my experience.

[E3E]

I have soldered and de-soldered quite a few Alps keyboards, and when I forget to solder one or more legs, the switch is all but certain to function erratically, if at all, in my experience.

Yes, of course! I'm not talking about every Alps board though, I'm talking about the Infinity in particular. I've also desoldered my fair share, and I do agree that this isn't something to do with just any PCB, but the Infinity is different in that regard due to very tight tolerances. So tight, it's possible to lift the PCB by the switch alone. I honestly don't think there will be any reliability issues with this. I understand the naysayers though.

I'll have a video demonstrating this shortly!

[E3E]

Bump because of added video. This works, and I honestly can't see how any practical usage of the board like this will cause any problems. I understand the naysayers, but I recommend that you try it yourself before being quick to brush it off! This could be something substantial for those who want to easily try multiple varieties of Alps without having to do a mind-numbing amount of desoldering (speaking as someone who has done a lot of desoldering and soldering work, tons of custom tuning on their keyboards, etc. I'm not a lazy halfass. )

[Magna224]

I would replace my closet full of keyboards and parts with BINS AND BINS OF COLORFUL RARE ALPS SWITCHES. It would be heaven.

[E3E]

I would replace my closet full of keyboards and parts with BINS AND BINS OF COLORFUL RARE ALPS SWITCHES. It would be heaven.

Follow the rainbow. Taste your nose. 

[hudson0804]

I have NO actual experience here but would it be feasible to have a double layer PCB, With one layer acting as the socket and a slightly off centred second layer used to lock the switches in place so there's no need to worry about them coming loose?

Just a thought.

H 

[0100010]

I have NO actual experience here but would it be feasible to have a double layer PCB, With one layer acting as the socket and a slightly off centred second layer used to lock the switches in place so there's no need to worry about them coming loose?

Just a thought.

H

There has been a prior project to do something just like that - like SIP sockets for the switches // let me find the thread.

EDIT : https://geekhack.org/index.php?topic=41004.0

As to the OP - I have to agree with the rest of others here.  Yes perhaps the Infinity board works well enough upon initial switch insertion to provide enough electrical contact through friction to function.  But, I would hazard that after some use and/or a few switch swaps that you would be in dire need of good soldering.

[E3E]

I have NO actual experience here but would it be feasible to have a double layer PCB, With one layer acting as the socket and a slightly off centred second layer used to lock the switches in place so there's no need to worry about them coming loose?

Just a thought.

H

There has been a prior project to do something just like that - like SIP sockets for the switches // let me find the thread.

EDIT : https://geekhack.org/index.php?topic=41004.0

As to the OP - I have to agree with the rest of others here.  Yes perhaps the Infinity board works well enough upon initial switch insertion to provide enough electrical contact through friction to function.  But, I would hazard that after some use and/or a few switch swaps that you would be in dire need of good soldering.

This is all speculation, on my behalf and on the others and yourself. There is simply no telling whether or not this will work in the longterm until testing though daily use and practical swapping is done. If you've seen my video, you'll see that I swapped the switches a few times, and I did this many more on the outtakes. It is possible the vias might develop wear from the insertion and removal of switch pins, but I cannot see that happening unless you are doing this multiple times EVERY DAY for a long period of time. Is that practical use? No, that's testing extremes.

I'll keep you all posted as I use my Infinity. I'm waiting to finish some painting on a keyboard I'm restoring before I clear coat my Infinity's case because I have a 2K clear coat that has a limited pot life once activated, so I need to clear coat everything at the same time.

For the Duck Eagle PCB I plan on modding to allow hot swapping, I can't do this method. It was just a stroke of luck that this happened to work for the Infinity. I'm going to be using http://www.digikey.ca/product-detail/en/8134-HC-12P3/A114106-ND/2280464 these to allow for a flush fit. It will require widening of the through holes and pads, but connections can be repaired if broken, and this is viable as someone else did drill through their PCB to add room for sockets on their Winkeyless.kr PCB, as mentioned in the LinusTechTips thread about hotswapping: http://linustechtips.com/main/topic/430702-custom-keyboard-hot-swapable-switch-build/

https://www.digikey.com/product-search/en?pv1567=23&FV=fff40016%2Cfff80311%2Cb9c0027%2Cb9c004b%2Cb9c005f%2Cb9c0074&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

These are the more popular variety for the hot swapping mod at the moment, but they do not allow for a flush fit. These could potentially be as easy as slipping in the through holes and soldering them in, since they are wide enough to accept Alps pins. It's true that once all of the switch positions have been socketed, the fit will be uniform, but I'd rather there be no change in the dimensions at all.

EDIT: Nope, skimming back through the thread on LTT, it looks like some of those don't even accept the 1mm MX switch pin well, so perhaps I went with the only decent option for Alps.

[E3E]

Accidental double post, my bad.

[E3E]

Couple of days using Orange Alps on my Infinity. No problems so far! I have found that it likely has to do with residual solder on these switches though, as the blues I had were not so reliable. :S

[E3E]

Update #2

Just got in some Green SKCL Alps in really nice condition from Ludovician. Swapped them in my Infinity without any solder and they're working fine. The Orange SKCM Alps I had in previously were working very reliably with no issues or failures for the week (it felt like two, I swear!) I was testing them. Only the Blue SKCM Alps had any issues. This was probably because I desoldered them from the Infinity itself, but any switches desoldered from an old board should fit and work in this keyboard without any issues or soldering.

This messages was typed on solderless green alps.