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geekhack Community => Keyboards => Topic started by: aegrotatio on Sat, 23 October 2010, 22:23:55

Title: How to rewire keys?
Post by: aegrotatio on Sat, 23 October 2010, 22:23:55

I've encountered situations where I cannot remap Ctrl to Caps Lock as I wish.  While using my HHKB Lite gets around this annoyance, I'd rather use something else because the layout is maddening.

How would I effectively rewire my Ctrl and Caps Lock keys on a regular keyboard?  What kinds of tools and proper gauge wire would I use?

Thanks...

Title: How to rewire keys?
Post by: Rajagra on Sat, 23 October 2010, 22:46:54

If the keyboard has a single layer circuit board, it would be fairly easy.

• Cut all the tracks leading to the switches you are swapping.
• Where there was more than one trace leading to a single switch solder point, you need to recreate those paths. Solder in wires to do this using any convenient solder points.
• Finally, solder a wire to each pin of both switches. Solder the other ends of the wires so you are conncting one switch into the circuit where the other switch used to be.

Really needs a picture, but it's late and I'm tired.

Title: How to rewire keys?
Post by: aegrotatio on Sun, 24 October 2010, 07:09:34

What gauge wire should I use?  What kind of wattage and solder?

Thanks!!

Title: How to rewire keys?
Post by: didjamatic on Sun, 24 October 2010, 08:55:47

I've had good success with 24 gauge solid copper wire. but you could go smaller.  My source is the individual wires from solid core Cat5e UTP network cable.  There are 8 wires in the cable.  I like this size because it's small enough to stick into the same hole in back of a pcb that a switch pin/terminal is soldered into.  It's also stiff enough to keep it's shape if you want to route it through the keyboard.  If you use stranded cable it will be rubbery and flexy and won't keep shape. Which in some cases might be what you would want as well.

I used to use a Radio Shack 40W cheapy soldering iron and it worked fine.  I have since stepped up to a soldering station but it's definitely not necessary.  I use 60/40 standard rosin core solder.  It's not lead free so I'm extremely careful with it.

Title: How to rewire keys?
Post by: rantenki on Sun, 24 October 2010, 11:24:47

Quote from: aegrotatio;237895

What gauge wire should I use?  What kind of wattage and solder?

Thanks!!

Get very small gauge wire-wrap wire with kynar or teflon insulation. The amount of current on a keyboard is nearly zero, so wire gauge can be very (30 gauge) small. The insulation resists the high temperature of soldering quite well. If possible, get old style fluxed lead solder, as the silver stuff has a higher melting temperature, and is more difficult to solder, especially for beginners.

In the unlikely event that you are trying to re-wire a membrane board, these methods are useless; you cannot solder to the membrane, however, you are not out of luck. Conductive thread (http://www.sparkfun.com/commerce/product_info.php?products_id=8544) and conductive epoxy (http://www.mgchemicals.com/products/8331.html) can also be used.