Custom Topre Keyboard?

[cooldiscretion]

I've seen so many people that built custom keyboards and modified keyboards, but one thing I haven't run across is someone who has build a custom Topre board.  It appears that one cannot just purchase a Topre switch (correct me if I'm wrong here), but it is only available on the boards that ship with it.  I'm curious how much work it would be and if anyone ever thought about building their own 60% programmable keyboard and ripping the Topre switches off say a Leopold fc660c since those seem to be the least expensive Topre option out there.  That would be one novelty board.

[Pacifist]

this has already been asked so many times. the answer is no

[Smasher816]

No one has designed a PCB that would detect capacitive topre swtiches.

If you want a programmable 60% topre board then perhaps you should take a look at getting a HHKB and switching out the controller. I have a guide for using a teensy with the HHKB.

[cooldiscretion]

this has already been asked so many times. the answer is no

Right, I guess I should have done a search before actually making a post.  It looks like there was one guy who was going to take a stab at it last year, but the thread seems to have died:
http://geekhack.org/index.php?topic=47601.0

No one has designed a PCB that would detect a capacitive topre swtiches.

If you want a programmable 60% topre board then perhaps you should take a look at getting a HHKB and switching out the controller. I have a guide for using a teensy with the HHOB.

That actually seems like a pretty cool idea. The only reason I initially brought up the topic was because I really like the look of all these 60% keyboards that are out, but the only Topre options seem to lack in case customizability (ie HHKB and FC660C).  That is a good idea of just modding the HHKB Pro 2 with a nother uC and putting custom firmware on it to get the programmable aspect.  Maybe someday the HHKB will be more customizable with cases or another Topre board will be released that fits a generic 60% case...

[Smasher816]

Yeah the lack of case options does kind of suck. There is the Digilog metal case for realforce boards but it is TKL not 60%. I think there have been some people who have came up with a metal case design for the HHKB but fell short on the IC's, mostly due to the extreme price. Ex: http://geekhack.org/index.php?topic=30759.0

Or there is the HHKB HG, but you really, really, don't want to try looking for that.

[hasu]

You will be able to 60% keyboard unit compatible with Poker case mount.

Fifst, get switch componets like keycaps, plungers, housings, cup rubbers from Topre(, OEM or clone) keyboards. Or some parts can be 3D printed your own like this: http://deskthority.net/workshop-f7/topre-sliders-mx-caps-t7437.html
Also reportedly Cooler Master NovatTouch uses Topre switches with Cherry keycap compatible plunger which will be preferable for keycap lovers. http://www.kitguru.net/forum/cooler-master-support-forum/20696-topre-switch-cherry-mx-compatible-novatouch-tkl.html

Next, you need just 60% PCB and plate. Some skilled people already their own PCB's and plates . Not so big problem here.

Finally, you need capacitive sense controller. Fortunatelly, we saw two controller projects for IBM Model F/BeamSpring emerged recently. Topre switch will be not so far from them, you can learn a lot from them.
http://deskthority.net/workshop-f7/beamspring-usb-controller-t6044.html
https://gitorious.org/kiibohd-controller/capsense-beta/source/111475c86d7cb889ae6a0456917b2cad17eb1125:

Much much work is needed, but it seems to be possible.

[Smasher816]

That's the spirit Hasu. Less people need to say it is an impossible dream and more people need to start working on it.

I'm sure that with all the great talent Geekhack has that this could become a reality with some work

[Oobly]

It's possible, but not easy.

Cherry MX and Alps are very easy to make a custom board with. You just need a plate or PCB for the switches to mount in and then hook them up in a matrix with diodes to a Teensy.

Capacitive switches (and particularly Topre style) are a whole lot harder. The PCB needs to be designed very carefully since stray capacitance will affect the performance. Then you need a controller that works with the particular capacitances yielded by your PCB design and the particular springs used. Then you need to get the rubber domes to match your layout (I think you can separate the domes from a donor board if you're careful). Then you have the basic functional pieces in place, but you still need a way to mount the sliders. This requires a special plate with slider supports, since the sliders are not supported by the actual switch mechanism, but only by the plate.

With a CNC machined or 3D printed plate and case and well-designed PCB it is doable, but you still need a donor board to get the domes and springs from, so it is expensive. Also you may need to tweak the controller to get it to sense the switches properly. For most people it's just too much work and too much cost to justify. On the other hand, it may be worth it if you're a Topre fan, there isn't a board out there that really suits you and you have good CAD and electronics skills.