Old matrix, new controller

[Hubbert]

Kind of a basic question, but if I wanted to replace the controller in various keyboards (old Model M, new Unicomp Model M, Scorpius, WASD), how easy is it to find headers to mate with the existing matrix? The mylar with white conductive traces is not amenable to conventional soldering.

[wcass]

old model m's use a "flat flexible" connector such as this:
http://www.digikey.com/product-detail/e ... -ND/688643

i have not disassembled my Unicomp, but have heard that they moved to a different system - probably similar to what is used in other membrane keyboards - press bars - which are cheaper and simpler.

you can make you own press bar to work with any matrix. design your controller with pad "fingers" similar to the traces at the end of the membrane. put mount holes on either side of each set of pads just wider than the membrane end. make a bar from steel (the stiffer the material the better) with holes to match those on the controller. make a sandwich - controller, membrane, foam, bar - and bolt together.

[bpiphany]

There is also conductive glue these days. I haven't used it myself, but I think it should work well for this kind of applications.

[Hubbert]

D'Oh: should have remembered this from a college class (though connectors were not a focus). I need to find the right header for FFC (flat, flexible cable), probably 0.1" pitch, like this.
http://www.adafruit.com/products/419

FCI Clincher is one brand name of something similar. But definitely no fabricating necessary.
http://www.digikey.com/product-detail/e ... ND/1002490

EDIT: A paragraph on page 6, "Interconnects"
http://www.holland1916.com/files/pdfs/H ... nGuide.pdf

[bpiphany]

Or there is glue... I am sure there is a connector to be bought somewhere. I am also pretty sure I remember people having trouble finding them on previous occasions, unless you want a couple of thousands...

[hasu]

And 3M embossed copper tape will also work. It allow you to solder even on membrane.