rfc relocating CTRL key below spacebar

[emit]

I recently purchased a kinesis advantage keyboard and I really like how the control/alt modifiers are activated by the thumb (heavy emacs usage).

I don't want to shell out $300 to get another kinesis for work, so I'm thinking about modifying a spare keyboard and moving/adding ctrl keys below the spacebar key.

I googled around and after finding no info I landed on this forum.

How difficult would this be? I have tools (drill, dremel, soldering equipment), but am not an ee.... can I just cut out the rubber section for the ctrl key (assuming no weird overlaps) and solder some wires between the cut parts and expect it to work?

[Lanx]

i'd say 2/5 in difficulty.
get some kind of switch (i'll just default to a cherry brown switch) then easily trace the wires going to ctrl and duplicate on the switch.
it probably won't be pretty.

[lowpoly]

\can I just cut out the rubber section for the ctrl key

What "rubber section"? Which keyboard?

[Findecanor]

If it is a rubber dome keyboard, then it works most likely by having metallic pads on flimsy plastic membranes. Re-routing traces on a membrane is very difficult and is not very durable. I have tried that, and destroyed a pricey keyboard in the process ...
You can't solder on a membrane, but .. depending on the controller, perhaps you could solder the two wires to the controller's circuit board (if it even has one) without the soldering points getting in the way of the membrane contacts.

As Lanx suggested, I too suggest that you get a mechanical switch, such as the popular Cherry MX. The Cherry MX switch is the same type (family) as in your Kinesis keyboard, You will need a Cherry-compatible key cap.
A Cherry MX switch can be mounted in a square hole of the right dimension on a plate of metal or plastic. It may be tempting to cut just a hole in the keyboard's case, but that will not give you the correct height.
Alternatively, you could get a Cherry MX switch that is soldered to a piece of printed circuit board cut from an old Cherry keyboard.  There are several members here who have modified their Cherry keyboards by cutting the numeric keypad, and one of them may be able to provide you with their leftovers.

[emit]

thank you for the input. I will investigate buying some cherry mx switches/caps and running wires to the circuit board. The keyboard is a logitech g15, and although it wasn't "cheap" (relatively speaking), i don't think it's mechanical. I haven't opened it up yet so I just imagined it's the type that Findecanor is describing (rubber dome --- it still feels very good to me).

I didn't realize solder doesn't stick to the metallic traces on the membrane. now there's no point in cutting out the existing ctrl keys, I'll attempt to add completely new keys.

[emit]

ok it does look like it's a cheap rubber dome design
http://techgage.com/reviews/logitech/g15_revised/logitech_g15_revised_24.jpg

[Lanx]

is it a g15 v2? (red)
cuz if it is, i've actually mapped and traced out every key, and i could actually show you mock up pics of what you could do.
http://geekhack.org/showwiki.php?title=Island:12439

[emit]

It could be. I have three g15s, the oldest one being the blue version... which appears to be the largest and roomiest for modding. However I'm open to dismantling the red version instead.

I've checked out your link and could not find the info on the traces (found lots of cool ideas though). Think I may just wait for your next update before proceeding.

[hoggy]

Have a look at the xstick.  You'll have to check that it can work correctly as a modifier... but the form factor should do the job.

[Lanx]

It could be. I have three g15s, the oldest one being the blue version... which appears to be the largest and roomiest for modding. However I'm open to dismantling the red version instead.

I've checked out your link and could not find the info on the traces (found lots of cool ideas though). Think I may just wait for your next update before proceeding.

well was going to wait to see if it was red or not, then i'd show you which traces you need to solder for ctrl

[Lanx]

so you'd have to unscrew your g15 then watch out for the multitude of ribbon cables.
The g15 v2 (red) to me seems pretty sturdy with the ribbon cables. also you might NOT want to unhook the membrane from the keyboard controller, cuz it's kinda unwieldy putting it back together.
either way once you do that, get to the underside of controller (see the orientation of the usb headers for reference) and solder wires to those 2 points, they will make ctrl.
You can even test it out by having you g15 plugged in and having a wire hit both those points and you'd produce ctrl (i do this but that cuz i'm modding).

solder however you can, i linked pics and said how i did it in my mod. if you want to go that far there's a nice little spot where you can install a switch right under the g15 spacebar.(the shiny plate)

[Lanx]

better pic w/o the wires soldered

[Findecanor]

Have a look at the xstick.  You'll have to check that it can work correctly as a modifier... but the form factor should do the job.

I would recommend to take a look at the xstick, if it didn't cost  $99.95 !

If both keyboards are USB keyboards, then modifier and letter can be on different keyboards... in general. I don't know the details of the USB protocol enough (and how it is actually implemented on Windows/Linux/MacOS) to tell if it will work in all circumstances, with multiple key presses, etc.

[emit]

and solder wires to those 2 points, they will make ctrl.
You can even test it out by having you g15 plugged in and having a wire hit both those points and you'd produce ctrl (i do this but that cuz i'm modding).

solder however you can, i linked pics and said how i did it in my mod. if you want to go that far there's a nice little spot where you can install a switch right under the g15 spacebar.(the shiny plate)

thank you, this is all/exactly what I needed.

[Lanx]

I would recommend to take a look at the xstick, if it didn't cost  $99.95 !

If both keyboards are USB keyboards, then modifier and letter can be on different keyboards... in general. I don't know the details of the USB protocol enough (and how it is actually implemented on Windows/Linux/MacOS) to tell if it will work in all circumstances, with multiple key presses, etc.

i don't know what this means, but for what it's worth the only things that would be activated on that one keytrace (connected to the 20 pin) is only ctrl. (r and l ctrl)
 or rather the only cluster for that is ctrl
the same could be said for shift/alt and win keys all have their very own cluster
while something like g/r/v/p/k is all one cluster.

[Findecanor]

What I mean is that with USB keyboards, you can plug in two USB keyboards in different USB ports on your computer, press Shift on one keyboard and 'a' on the other keyboard and get a capitalized 'A'. This works with all modifiers, including Ctrl. I was pretty astonished when I found out that it worked and that Windows did not require both modifier and letter to come from the same device for them to be recognized.

[Lanx]

thank you, this is all/exactly what I needed.

sure thing.