Anyone knows a method to make your own flexible matrix circu

[LukStarkiller]

I know that as a first post, this isn't very appropiate, but after reading a lot this forums. I had this question, and it's a good place to post it.

I'm trying to build an hybrid from two keyboards (an ibm M and a G15), but I need to make a new matrix. Designing the matrix it isn't dificult, But then I don't know how to "print" the matrix.



I found several companies that make flexible circuitry and some of them exactly like this, but all of them in large quantities.

Looking for DIY, I found in Instructables a guide to make flexible circuitry on copper. But it seems to bend and deform too easily, unlike a printed matrix.



Anyone know a company that does this in little quantities, or another method to make one?

[Findecanor]

I think that you would be better off with one of those "battleship-sized" 122-key Model M (or Model F) keyboards and a customized adapter to USB. You could make the adapter from a Teensy and Soarer's firmware, and modify the firmware somewhat.

I think that perhaps a membrane switch could be emulated by using a sheet of conductive mylar over perforated film (from the original assembly) over a rigid PCB. The mylar would just close circuits between traces on the PCB. I don't think that anybody has tried this, so I am not sure that it would work. It is just one of those ideas that have popped up.

[hasu]

DIY membrane matrix is interesting.
How about conductive paints for lines and pencil carbon for contact?

[wcass]

yes, i thought about this too. i am big into moding IBMs. i have not tried this out, so if you do, let me know how it works.

for substrate, model m uses clear polyester film. you can get this at art/drafting supply shops. bottom sheet is 5mill, top is 3mill (center is 5 mill, but you probably can reuse what you have).

for traces, the model m uses conductive silkscreen. a diy alternative might be silver ink pen such as Caig CircuitWriter http://store.caig.com/s.nl/sc.2/category.174/.f

good luck!

[LukStarkiller]

...for substrate, model m uses clear polyester film. you can get this at art/drafting supply shops. bottom sheet is 5mill, top is 3mill (center is 5 mill, but you probably can reuse what you have)....

Thanks for the info

[Kurk]

Another possibility would be to make your matrix with conductive thread using a sewing machine or even better an embroidery machine. I don't know if this is feasible for keyboard matrices though...

[hasu]

I got a CircuitWorks Nickel Conductive Pen last week to repair small failure on membrane traces of Model M.
Masking fixed traces with tape just apply conductive paint from the Pen, it worked fine.
Also it is enough durable for contact edge but not sure for key pad.


Its trace thickness might be some problem for making all over matrix traces. Need good squeegee?
Another big problem is its cost. Cheap conductive paint for guitar anti-noise purpose might suit for matrix trace.