Best key switches for home-made keyboard w/ extra-large caps

[sirylj]

I'm currently working on a project to make a home-made keyboard with home-row key size of about 0.75 inches. --> http://geekhack.org/index.php?topic=36637.msg690670#msg690670

However, I wanted to post here to specifically ask about keyboard switches.
I need to order a set of 105 keys and originally looked at the MX-C1NW (I think Clear) switches on Mouser, but was a little shocked at the price (never bought switches before).

So I'd like to ask what people think are the best key switches for the price:
MX Blacks (MX1A-11NW) are cheapest at $0.641 ea. ($67.305)
MX Blues (MX1A-E1NW) are in the middle at $0.709 ea. ($74.445)
MX Clears (MX1A-C1NW) are at the top price at $0.860 ea. ($90.30)

Also, I'm held down in my buying options because I don't know any other key switch types, so if you have an alternative that isn't Cherry MX and is cheaper I would love to hear it.

Thanks for any help

[rowdy]

Buy a cheap (~$15) keyboard on eBay and spend a few minutes desoldering the switches.

[sirylj]

I've thought about using switches off of an old keyboard, but how likely is it that I would be able to get custom keys (0.75 inch) that will fit them? I have been looking at Signature Plastics and contacting them (might just go to Shapeways and use a high quality material), and when look at their mounts I'm not sure whats 'standard' or if non-standard mounts will drive the price up even more.

[rowdy]

If you want Cherry MX switches, they all have a standard, er, stem that the key caps fit on to.  Doesn't matter if they are vintage blacks or shiny new greens, they are all the same size.

If you have larger than usual key caps, you will either need a custom plate, or just PCB-mount them.  The latter approach will allow you to space them as you wish, but you might need to design the board yourself.

[alaricljs]

And the other thing is that the mounting pitch of standard Cherry MX keyboards is.... .75"

[sirylj]

@alaricljs
When I say 0.75 inch, I mean that I am looking for a key where the size of the top is 0.75 inches wide by 0.75 inches tall.
So I'm actually not sure if a key cap of larger size would even fit on a Cherry MX, or if it would not matter (just hang on the edges a bit).

@rowdy
I'm not too familiar with a keyboards insides: If I PCB-mount them, they will just be on the PCB and will not need a plate or something to cover the PCB (as the keys will cover it), correct?

Also, I have looked into designing a PCB as I think I will have to get a custom one to do this.
I've looked over the Humble Hacker thread (dmw), the Homemade keyboards thread (bpiphany), and KiCAD design guide (deskauthority.net), and think I might be able to pull it off.

[rowdy]

@rowdy
I'm not too familiar with a keyboards insides: If I PCB-mount them, they will just be on the PCB and will not need a plate or something to cover the PCB (as the keys will cover it), correct?

Yes.

Non-plate mounted also means is is easier to maintain, customise or replace the switches later on as yuo don't have to desolder the switch to remove it from the plate just to remove the top of the switch.

[sirylj]

Well, I think I have an old keyboard somewhere, and if not I can get one at AmVets.

Next step is to design a PCB board then, so I need to decide whether to order one through ExpressPCB/other company or make my own. I've never done this before so I'm inclined to just order one for simplicity, but I really need to keep costs down (I just know the keys are going to be super expensive, and I still have to get a case for it, so I sadly might have to go tenkey-less).

[furosuto81]

Also, I'm held down in my buying options because I don't know any other key switch types, so if you have an alternative that isn't Cherry MX and is cheaper I would love to hear it.

Thanks for any help

Matias's new ALPS-style switches should be available shortly, though I couldn't tell you the final price. I'm sure if you asked in the Matias forum, he'd give you an answer on price & ETA.

[alaricljs]

Matias had given an impressively low pricetag at one point, much cheaper than Cherry MX.

As to the mention of .75" pitch, My point is if you are willing to forego .05" you might be able to just go with custom keycaps and mount them on a standard keyboard.

[fohat.digs]

This is not a trivial project. You should buy used keyboards with a couple of different switch types to disassemble and experiment on before investing the time and money for the "final" prototype.

Three quarters of an inch is a very standard key pitch, "pitch" being the measure from edge of key to edge of key. I had a keyboard once, that I sold, with a pitch of 1" and the key tops were probably at least 3/4" square. It was branded "Milton-Bradley" and sold as a children's keyboard, but I sold it to a guy for his grandmother.

I hate laptop keyboards with flat keys and no space between them, but not everybody feels this way.

Personally, I like tall keys with a good deal of "air space" between them.

Before you do anything else, make sure that you can find the keys that you want before you start laying out a switch configuration.

[sirylj]

Matias's new ALPS-style switches should be available shortly

Researched it quite a bit and it looks super interesting, and I think it will be a far more doable approach that harvesting an old keyboard (due to different mount requirements.) Can't wait to see the switches go available (I think on Amazon? Probably on his site too though.).

Matias had given an impressively low pricetag at one point, much cheaper than Cherry MX.

Super low, $100 for 800 switches for 12.5 cents per switch (a bit too many switches for me, then again, there's always group buys).

Before you do anything else, make sure that you can find the keys that you want before you start laying out a switch configuration.

Thanks, I'll take your advice into consideration. My biggest obstacle (ATM) is getting the keys that I want to be able to use. Signature Plastics is not a viable option ($1200 for each new shape) and I've heard that Shapeways keys aren't strong enough. Molding my own (there's a thread here somewhere) might be an option, as I can increase the thickness to get a larger key cap, but at that point it would be easier to just order them from Shapeways (I don't thinking my own molded keys would be much stronger anyhow).

[alaricljs]

He later posted that they would sell in lots of 200.

Your own molded keys are likely to be stronger than shapeways.  What you might want to do is create 1 of each shape w/ shapeways and then run molds off that to cast your own caps.  Solid cast plastic is stronger than printed under most circumstances.

[sirylj]

What you might want to do is create 1 of each shape w/ shapeways and then run molds off that to cast your own caps.

That's a great idea, I hadn't even thought of getting a key cap of the size I want to mold off of, I've just been thinking of adding on plastic to a regular key cap to make it larger.

One of my many next steps is to make a 3d model of a key cap then, probably with Wings 3D (time to head over to TaleWorlds).

I  know what the general shape/size of the key cap should be, but I do not know the exact measures of the mount for the Matias switch, so that will be the first obstacle for my key caps.

Matias' switch is ALPS-style, so the mount will be the same measurements as any other ALPS switch, right?