Universal Matias/MX plate viability

[shamanas]

Hello everyone.

I'm quite a noob and I've never even soldered anything, let alone built a custom board but lately I've been thinking of designing my own board.

I've got a list of features and a layout in my mind (and some pen and paper stuff - quite a lot actually ) and one of those features is the ability to hot-swap (I'll describe what I have in mind in another thread sometime) both MX and Matias switches (and a mix of both at the same time).

Of course, for this to be possible, the first the obstacle is actually having MX and Matias support on the same board (although having both on a single board may not be practical, I would like to achieve this for the cool-factor/as a technical achievement).

I know that this is deemed impossible, because MX switches need an ~1.5mm plate, while Matias switches need a ~1.2mm one.

Now, my idea is basically having "padding" for MX switches, basically a 0.3mm hard ...thingy pad... that sits between each MX switch and the 1.2mm plate.

(Tl;dr)
Attached is a basic image I made in 15mins to demonstrate what I mean (the "padding" is the red area)

Do you think this kind of "padding" would be viable? Would the switch be too wobly (would it sitat all )?

Thanks for reading and your help!

Cheers, shamanas!

[Findecanor]

MX switches don't actually need to snap to the plate. A plate adds only some stability. If you use MX switches with "PCB mounting pins", they are even sturdier.

BTW. You can't swap MX and Alps in the same place, because they have differently-sized mounting holes and I am not sure that a hole that is large enough to fit both MX and Alps would be able to hold Alps as sturdily as a regular Alps mounting hole.

[jacobolus]

Matias themselves are making some:
http://geekhack.org/index.php?topic=60268.0
http://geekhack.org/index.php?topic=602 ... msg1447591

A ~1.3–1.5mm thick plate should work for both Alps/Matias and Cherry MX switches, getting them to both snap in. I definitely recommend trying to get your switches to clip/snap to the plate, as it substantially improves their stability. I don’t think your little pads will help, but feel free to try it and report back!

You need to do some testing to get the switch holes exactly the right size though, and I’m still not totally convinced that a plate supporting both types of switches will be as nice at stably holding Alps switches as a plate with standard rectangular Alps cutouts.

[shamanas]

Wow, thanks for the links jacobulous, I never stumbled upon this, or any custom where the same plate was used for MX and Matias switches (I have seen the universal PCB & plate mounting holes image though)!

I thought of the mounting hole issue for ALPS but I guess it's something I will have to try to find out how wobbly the switches get.

Findecanor, the issue is that I intend to make the switches hot-swappable, so they won't be soldered to the PCB, meaning the plate has to provide good support, not just some stability.

Thanks for your answers, I appreciate it!

[Muirium]

Plates aren't the whole story.

Alps (including clones like Matias) and Cherry MX have different geometries in the 3rd dimension, too. I can never remember the numbers, but as I recall the plate is mounted closer to the PCB for Alps as the switches take the plate at a different height. Someone with an actual clue, rather than a hazy recollection, could be useful here!

Also, there's caps. Alps are a real problem for us custom builders because of the scarcity of caps. You wind up reusing them from classic keyboards, which is fine, but you're stuck with whatever layout was on the original. Certainly, you can't get as out there and inventive as a nice new set of Granite let alone Round 5 would handle. Matias himself has said that we will be able to order caps from him sometime, but I've low expectations for their customisability or indeed quality. His switches are the best thing he does in keyboards. The second best thing is his stabs. If we can order up those, and alter them to our will, we could open up a fair few options from other Alpine classics.

[Daniel Beardsmore]

Alps (including clones like Matias) and Cherry MX have different geometries in the 3rd dimension, too. I can never remember the numbers, but as I recall the plate is mounted closer to the PCB for Alps as the switches take the plate at a different height.

I figure that you could accommodate for that with the hotswap pin sockets though …

[shamanas]

I intend to use Mrinterface's MX/Alps adapters for caps (and possibly an MX/MX one to achieve the same keycap height)

As for the 3rd dimensions, as Daniel pointed out, this can be arranged using the pin sockets.

Basically, my idea for hot swapping is not sockets that are basically flat (like the Smart68, I couldn't find any of those anywhere anyway ) but adding an additional layer between the plate and the PCB.

This layer will be insulated and have according holes for sockets.

That way, by having the layer be as thick as the longest pin of the two switch types (MX/Matias), you also eliminate the issue of the 3rd dimension.

It also makes the PCB design simpler.

I don't know if my idea is totally stupid though, sounded good yesterday at 3:00 am