custom projects using scissor switches?

[IanM]

I recently had a brief play with some of the slimline keyboards on display in a store:

• Microsoft Wedge
  Microsoft Arc
  Logitech slimline/bluetooth (a few different ones that I didn't get the proper names of)

I think they are all scissor switches but that's the first question, if I'm wrong about these Wedge/Arc type keyboards being scissor switches then what are they?

I was surprised that they were generally better than I expected, particularly the MS Wedge which felt reasonably solid with a stable key action - I think only the space bar was not as good as it was on the Logitech. The Logitech were OK, but I just felt the key action was subtly not as good as the MS, and the Wedge has nicer key spacing as well (I found the big gaps between keys on the other keyboards a bit unnatural.) However, the Wedge is Bluetooth only which is of no use to me as what I'm thinking about is a small keyboard for a gaming PC that will not need to be used for a lot of typing or work, just some browsing and email writing.

I've also been thinking about custom gaming keyboards/keypad controllers for a while as well, so before consider this any further, I'd like to know:

• i) are scissor switches and keycaps available to purchase or would it be necessary to buy doner keyboards and butcher them for parts?
  ii) are there any custom projects that others have previously attempted? If so where can I read about them?

Thanks!

[Findecanor]

Typical scissor switch keyboards are not individual switches like Cherry MX or Alps that you can combine how you like on your own circuit board or plate.
Scissor switch keyboards are typically made in larger parts that are used for all switches on the keyboard. A single metal sheet or plastic part has notches in it which holds the individual scissor mechanisms in place. The actual contact mechanism is based on a couple of plastic membranes with tiny rubber domes glued to them. There are also holes in the membranes for the notches.
These are made in machines, with custom tooling for each keyboard model/layout.

Making your own membranes is hard.
There have been a few people that have modified existing membranes using conductive ink or different types of metal tape, but these are quite fragile and/or not conductive enough for a complete keyboard. For instance, it is hard to get conductive ink to stick to flexible plastic.
The most promising idea I have heard about for making a custom membrane involves a very crude top membrane with a horizontal strip of metal tape for each row, with a rigid circuit board underneath. However, I read about that only today and the guy has not built it yet. I am very interested in seeming the outcome.

Typical gaming keypads (such as Playstation controllers etc.) are often regular rubber dome switches (conductive rubber on the bottom of the rubber dome) or microswitches with a regular plastic plunger on top. That would certainly be possible to build yourself.

Scissor switches are not the only option for a slimline keyboard, though. You could use Cherry ML, which is a mechanical switch, but not everyone likes them as they are a bit scratchy and not as smooth as scissor switches.
There are also slimline keyboards with regular plungers over rubber domes, but they are sometimes cheaply made and not as low profile as scissor switches.

[IanM]

Thanks for the reply Findecanor, lots of useful info. I'll have a good read through the thread on the link.

Ages ago I posted some thoughts on gaming keyboards - the gist of it being that I think short travel makes more sense (to me) for gaming and game controllers are probably a better thing to mimic than 4mm travel mechanical switches. PS controllers are a bit mushy? I think the N64 controller has more solid buttons but iirc when I was thinking about it before I felt that they would be too light and lacking feeling for a basic keyboard that would do a tolerable job for light tying. For a pure gaming controller it probably wouldn't matter, and maybe something else would be better suited than scissors anyway.