Before I could start final assembly, there was one more electronics problem I was struggling with.

So I have some buttons pretty much exactly like this one.

They are 3-pin 12V illuminated rocker switches. I bought 3 of these and will be using them as a power switch, a ‘spindle override’ and a ‘limit switch disable’ (in case I run into problems with false triggering later on). The problem is the 2 latter work with 5V signals, not 12V. 5V versions are not sold anywhere, which I find strange, but it is what it is… I set my mind on these switches though, even if only for the sake of uniformity I had to make it work.

I sketched up this resistor divider schematic (you can see the internal layout of the switch). Theoretically it would provide 4.8V to the 5V relay but since I have very little experience with electronics, I was not confident enough to go this way.

I started thinking maybe 5V would be enough to light up the internal light. It wasn’t a LED as I initially thought, it was an actual mini-lightbulb. 5V only made it glow very faintly, too little to be usable.

So I came up with another solution. If somehow I could replace the internal bulb with a resistor-LED combo, it could work on 5V.

So I made a quick test setup. Without and with switch cover. Now this is looking promising.

Building it into the switch was not as fiddly as I anticipated. It actually got in pretty easily.

Again without cover and fully assembled:

 

So there you have it, it now lights up with 5V without any visible modification outside!

Note I made 2, an orange and a green one, photo’s are switching between them.

The third switch is the power switch, which relays 24V, but I simply attached a +12V lead to the ‘ground’ pin of the switch, which left a perfect 12V for the light.