Cheap mechanical keys?

[marieidat]

Hi there,
Bit of a silly question from a noob, I'm afraid. Please humour me!
I'm in my final year of a Digital Art and Technology degree, and want to hack a keyboard to use the switches as inputs - a keyboard will mean ready-made easy input switches, rather than trying to make a custom PCB.

So, my question is, if I'm not interested in keypress quality or any sort of "usability" or "enjoyability" aspects, but just want a cheap, basic mechanical keyboard, what sort of thing am I after?

The cherry blue and cherry brown buttons look like exactly what I'm after, is that what's in here? http://www.keyboardspecialists.co.uk/Shop/KBS/Product/2919/J82-16000/CherryJ82-16000EntryLevelKeyboard.aspx

What about this?  http://cgi.ebay.co.uk/Dell-IBM-HP-Compaq-PS-2-UK-KEYBOARD-Cream-/180622794159?pt=UK_Computing_ComputerComponents_KeyboardsMice&hash=item2a0df51daf

[Parabellum]

Neither one of those keyboards are mechanical.

Go nuts:
http://geekhack.org/showwiki.php?title=START+HERE+--+The+Geekhack+Mechanical+Keyboard+Guide+-+Includes+Glossary+and+Links

[ch_123]

Look on eBay or local old computer part recyclers for Model Ms or Dell AT101Ws.

[Superfluous Parentheses]

As far as I know, neither of those are mechanical.

Cherry branded MX boards generally have model numbers starting with G80 (though there are a few models that don't), but expect to pay somewhere around $80 to $200 dollars for a new one, depending on how specialized the specific model is.

As for using the buttons for projects, if you can live with keeping the switches in their original layout, and you have some electronics knowledge, you can probably convert any keyboard if you swap out the controller or convert usb/ps2 output.

If you want switches that you can easily rip out and reuse, you need a board with self-contained switches. That would exclude all IBM Buckling spring boards (since they rely on a membrane + matrix or tricky capacitive systems) and Topres (which would be too expensive anyway). EDIT: it would also exclude any "pure-rubber" keyboard, which is 99%+ of everything sold today. The common switches you could use would be Cherry MX or ALPS (ALPS are AFAIK not manufactured any more, but you can find second hand boards that have them).

You're probably going to have to go second-hand anyway if you want to save money. The cheapest second-hand mechanical board I've seen around with discrete switches is the Dell AT-101 which has black APLs switches. Not great to type on, but not horrible either.

[theferenc]

So, out of curiosity, what exactly do you want to do?

Will the keyboard be used as a whole object, or will each switch be connected to it's own input signal, independent of the keyboard itself?

Either way, take a look at the classifieds section here, ascaii might still have some inexpensive used models kicking around with Cherry switches.

And welcome to geekhack!

[Superfluous Parentheses]

Seconding the recommendation for the classifieds section, especially if you just need parts. For example, laden3 is currently offering a whole set of cherry MX  brown switches (loose) at $0.44 a piece. Though those probably come without the key caps.

You could also watch for broken 'boards - most of the switches will still be OK unless the whole thing has rusted shut.

[Pylon]

If you want individual switches, Alps are probably the best as I believe they'll fit on a standard 2.54mm-spaced PCB. Cherry MX requires a custom PCB.

For Alps, look for Dell AT101Ws. Also, this is new, uses clicky Fukka-type Alps switches, and should also work well.

[Tony]

I am using a Compaq MX 11800 with brown switches and I heartily recommend it. This keyboard is fine for both typing and gaming.

You can usually get one from ebay for around 40-50$.

[bakageta]

Let me get this right... It's not the switches you want to use, it's the keyboard you want to use, with inputs wired up to various keys so you don't need to make a custom pcb? Depending on how many keys you need to press simultaneously, you may need an NKRO board. Most are 2KRO, which means a minimum of 2 keys at the same time, though if you only need a small amount of inputs you can pick and choose ones that won't interfere and get up to 6 or so.

I'd recommend a Cherry G80-8200 PS/2. It's NKRO, which means you can press every key at the same time, and uses cherry brown or cherry clear switches generally. They're pcb mounted and easy to desolder individually. Here's one, but it's a little expensive, they can be had cheaper if you're patient. I've picked up 2 so far for around $30-$35 shipped each. I'd make a post in the classifieds section here, someone might have one they could part with.

[marieidat]

Brilliant! Thank you so much for all your help!

I am amazed by the wealth of information and help, and the different types and designs - I never paid keyboards much attention before, suddenly I have a new (v. geeky) hobby

I wrongly assumed all keyboard were mechanical, and was very dissapointed last week to find 3 acetate membranes in my spare keyboard... but I'm still continuing my attempts to attach wires to it (there are some conductive paints and glues I'm trying).

It's a bit of an ambitious project, but I've got nearly 3 months... I'd like to make a physical version of one of these: http://lab.andre-michelle.com/tonematrix
The alternative I'm looking at is using an Arduino board and switches. Once I've got my inputs, I'll be building in Flash.

So ideally I want switches that I can rip out and reuse,  to be able to spread out the keyboard keys a bit - so self-contained switches it is. I'm hoping to be able to reuse the controller and cable too (either USB or a PS2 with converter) but this might be WAY too optimistic.

So... I'm after ALPS or Cherry MX switches, which is really helpful, thank you!

Ooh, and Bakageta, that looks great... thank you... will be on the lookout for one of those.

[bakageta]

Yeah, I would definitely go with something that's NKRO, simply desolder the switches, mount them on a panel in a grid to match your design, and run wires from the switches back to the pcb. That way you won't have any problem no matter what keys get pressed at the same time.The only problem I'm seeing is that I don't see how you can have enough keys... I mean even just a single octive is 192 keys, or 112 if you don't include sharps/flats. You could probably pull off 112 with they keyboard I mentioned, but I'm curious what your design was initially.

Anyway, it sounds like a neat project. I really hope you'll do a writeup in the modification section to show it off.

[Brian8bit]

I think you're barking up the wrong tree enquiring about switches here for the development of a "tone matrix". You would be better off looking at the custom built midi synthesiser crowd. This is effectively the tone matrix but in hardware (and slightly more complex).

[dotancohen]

but I'm still continuing my attempts to attach wires to it (there are some conductive paints and glues I'm trying).

Which conductive glues? I have had good luck putting a staple through the membrane on the conductive matrix, then going over it with silver conductive paint. In one spot I've had to put a drop of solder to prevent a staple from shaking loose the brittle paint, but other than that no problems. However, conductive glue would have been easier and safer than solder on the thin membrane.

By the way, this is my first post, but I've been hacking keyboards for years. I'll be posting often. This is a great forum, I wish that I had found it sooner.

[Findecanor]

If you want individual switches, Alps are probably the best as I believe they'll fit on a standard 2.54mm-spaced PCB.

ALPS switches can be mounted onto a stripboard/perfboard with 1/10" (2.54 mm) hole spacing only one-by-one, and then they are not sitting straight.
They can not be mounted in a QWERTY layout with 3/4" key spacing.
(Yes, I have tried)