Nagging DIY Questions


#1

Hey everyone, I’m an amateur DIY enthusiast. I’ve started to gain a little confidence in my abilities but I always make it a point to stay humble and seek advice. I’m a software developer professionally so the firmware side of things has been easier to acclimate to, but the more hardware engineering aspects of the hobby are still something I’m gaining my footing with. I wanted to stop in and ask a couple questions that have been nagging at me so I can better orient my next projects.

  1. Is there a distinct advantage or long term stability gain in a PCB over a hand wired matrix + controller? I see a lot of people refer to hand wiring as a good way to prototype. Since that gets repeated so often, it makes me feel as though a hand wired matrix isn’t a finished product but just an iteration of a concept.

  2. What is the ideal wire gauge when doing a hand wired matrix? I spend entirely too much time stressing over the small details. Most recently, its been wire gauge. I’d been planning to do a hand wired build with a Postage Board that LifeIsOnTheWire is running a group buy for and using 30AWG magnet wire for the matrix. Its easy to assume a small wire gauge will be entirely fine based on the size of PCB traces, but assumptions based on so little information rarely end well.

  3. What screw sizes do you prefer? This is more just curiosity than anything. I see some people using M3’s for corner screws on sandwich cases, I see others using M2.5’s, most people seem to be all in on M2’s for all things. I figure it comes down to availability more than anything else.

  4. What plate material and thickness do you prefer? I recently did a pretty thick plated acrylic build that was a good learning experience, probably going for an aluminum 1.5mm plate next for a more travel friendly board. I’m always curious to see what material people go by for plates since they change the sound and feel a fair amount.

Thanks for any answers in advance!


#2
  1. PCBs makes your keyboard sturdier and is fastest to assemble, hand wiring allows you to experiment with exotic layouts faster and can be cheaper.
  2. 30AWG magnet wire is fine. What dictates the wire gauge is the current that will flow through it. Digital signals on keyboards are very low current, you can use magnet wire without problems.
  3. If doing a sandwich-style, hand wired keyboard, use whatever screws/nuts you already have. M2 screws are used on 60% keyboard cases to attach the PCB on it, so they are kind of common among enthusiasts. I myself use M4 screws on sandwitch cases just because I already have plenty of them.
  4. Plate material is a personal choice. Aluminum and stainless steel are the most common, but brass as plate material have been rising in popularity in the last year or so. Now, plate thickness is usually dictated by the switch choice: Cherry MX switches and clones requires a 1.5mm ± 0.1mm plate thickness to allow a snap fit. If I’m not mistaken for Alps and Matias switches you will want a 1.2mm ± 0.1mm thick plate. There are some people who likes 5mm thick acrylic plates, but those requires gluing the switches, as they don’t snap fit.

#3

For screws, I was mostly curious because I have a handful of different types laying around and was curious if anyone had strong feelings around one or the other. The approach on my next build likely is going to be fitting standoffs into my center layer and threading my top/bottom layer screws into the standoffs. For the ones I have, a 3mm hole fits them exactly enough that there won’t be any play.