[help] hand wiring with metal plates and acrylic plates without hot melt/glue

[ag123]

hi

i'm planning to build a custom keyboard and doing hand wiring, i'd not be using any PCB hence the plate is key to making it work. i've read various things about using 1.5mm thick metal plates e.g. aluminium or steel.
my question about aluminium or steel plates is has anyone used just the aluminium or steel plate with hand wiring without a pcb? do the switches stay on the 1.5mm snap-in grooves or do they fall off easily without any pcb?

then my current plans is to use acrylic plate, partly as i'd be able to use thicker plates. however, i've read here and seen various examples of using hot glue to bond the switches to the acrylic plates. e.g. https://henrycnguyen8.wixsite.com/keyboarddiy/handwire-guide?lightbox=dataItem-j39r7x6u

i think this is a good way to get a keyboard up and running but i'd think this would be nearly impossible to maintain e.g. should a switch be defective or that there is cracks in the acrylic plate

has anyone succeeded with using thick e.g. 3-5mm acrylic plates without using hot melt to bond the switches? e.g. would the switches pop out easily with a (thick 3-5mm) acrylic plate?

i'm actually of thinking of some mods like drilling 1mm holes at the bottom center pole of the switch and threading a nylon cord (fishing line), i'm still searching and thinking out solutions to use the switches with acrylic plates without hot melt

thanks in advance

[TalkingTree]

MX switches are actually designed to snap into 1.5mm thick plates, so you'll definetely have to glue them into a 5mm one.
To answer your question, yes, many have successfully hand wired keyboards with metal plates.

What layout are you after?

[ag123]

thanks for the feedback !
i'm basically taking the ansi 104
e.g. from
http://www.keyboard-layout-editor.com
adding more keys that i need and run them in
http://builder.swillkb.com/
to get the cad

the trouble with thick acrylic plates is that they would not fit the switch grooves but if one use hot melt/glue to bond it to the plate with the switches the keyboard become unmaintainable as it would likely be (very) difficult / impossible to remove the hot melt on the switch / acrylic when it becomes necessary to remove and replace a faulty switch or if there is some serious cracks on the acrylic plate

the thing i'm worried about is that as i'm hand wiring the keyboard (i.e. no PCB) would using an metal (aluminium) plate suffer the same consequences as when using acrylic i.e. the keys comes loose despite the snap-in grooves. This is because i'm not using that additional PCB which would give some additional bonding from the soldered joints

And as for acrylic plates, i'm still trying hard thinking of / finding a solution to do without hot glue, one of those things i'm thinking of is to drill a 1mm hole at the center pole protruding at the base and thread a nylon cord (fishing line) through it and securing it around the plate. but i'm not sure how much would that help

at one point i'm even thinking about drilling holes through the switches and slot a thin metal rod / wire (say 1mm) thorough the acrylic plate and through the swiches, that would go in a pretty strong way to reinforce the switch and replace the use of hot glue.
however, as drill bits has limited depth, i'm not sure how i'd drill through some 150mm of acrylic to insert the rods

i'm not sure if such rather extreme means is necessary if hot glue isn't used and that the keyboard is hand wired (i.e. no PCB)

[TalkingTree]

More keys such as?

[ag123]

i used to have a logitech keyboard which has a 'power' key. pressing that power key apparently send the keycodes for the system to shutdown
(i.e. single key shutdown, single key suspend etc)
this would be more towards those 'multi media' keys on keyboards
the motivation for building a custom keyboard in part is that i'd use a controller i know with it e.g. some 'arduino mcus', in that way i could re-map keys that i'd like and add 'extra functions' which is otherwise not available on standard 104 key keyboards (such as that single key power down and single key suspend)

[crystalhand]

So here is my thoughts on this as I have done a great deal with 3d printed cases.  I generally use them as the plate and hand wire. 


If you can get 1.5mm plate you are golden.  These hold the switches amazingly there will be no worry about them coming off unless you want them to.

I think you should consider the hot glue a bit more than you currently are.  I find that it seals and holds the switches on great when the plate is thicker than 1.5mm.  It is also not that bad to get the glue off if needed.  While it does take some time its doable. This is assuming you did not literally flood the keyswitch with glue and instead used a reasonable amount.  The hot glue can be picked off with a sharp knife or re melted to make it easier to remove.  I do not think it is all that more troublesome compared to de soldering the switch. 


I recently had to clean up the hot glue on one of my boards hours after putting it on.  The hot glue had dripped down into the click action on a few box switches. It took me about 40 minutes to clean the glue out of 10 or so switches.  Slightly annoying but no more than that.

[Arbor]

Here is another idea for non-glue plates: I have used in the past a 1.5mm acryclic plate with precise holes (i.e. 14mm high) where the switches will click into; however, 1.5mm is too flexible for acrylic, so I used another 3mm acrylic plate with larger holes (~16mm) to fit exactly under it (and glued to it). This makes it rigid, while having the switches clicked into to the top plate.

Hope that helps 

[ag123]

hi thanks for the response, i didn't notice the additional responses earlier.
@ crystalhand
thanks for the feedback on hotglue, i'd think i need to experiment and see for myself how that works, i'm having an impression that the hot glue would bond to the switches effectively making it not possible to remove. the melting hot glue part is an interesting feedback
@Arbor
thanks for sharing the cool idea about the 2 plates approach that sounds like a good idea to experiment with and is rather easy to make,

[ag123]

hi all, thanks for the responses, as i'm pretty much noob for the pcb techniques and that i'm thinking out ways to make a pcb for a custom keyboard, hence i'm thinking aloud
one of those things that i'm  thinking is that since we can laser cut an acrylic plate, we can also laser cut an acrylic keyboard pcb.
the trouble would be that then the wires need to be laid out manually rather than etched like conventional pcb
and given that acrylic is pretty soft, if we use 1.5mm acrylic it would likely be very wobbly.

but laser cutting the 'pcb' is a rather interesting idea, the main thing is that it can take care of all that holes which the switch and the 2 terminals sit at good precision, this can save a lot of effort / time.

other ways i'm thinking of is to get FR4 pcb boards, possibly without the copper and laying out the wires manually
but large boards aren't quite easy to find really. especially on ebay  / aliexpress

and oh yes, lets just say that i go with the 'laser cut acrylic pcb' and say it is 4mm thick (vs the conventional 1.5mm thick, how am i going to solder the pins which is at most 3mm (slightly more than 1/10") long? i go to a rather extreme thoughts about using brass eyelets, that can help extend the hole so that i'd be able to solder them even on thick acrylic sheets,
https://www.ebay.com/sch/i.html?_nkw=1.5mm+brass+eyelets&_sacat=0

oops, this reply is intended for a different thread