Generic keyboard/keypad keys? - Page 1
Forum section: electronics / projects

author: Andrew_K
author_rank: Contributor
timestamp: September 20, 2016, 10:24:35 pm
content: Hey all,I'm looking to incorporate keyboard keys into a few embedded projects of mine, but I'm trying to avoid using Cherry MX switches as they are pricey.I know they have to exist somewhere, but I can't seem to find any to buy online. I'm looking for something like thishttps://sli.mg/a/gV0pVJ. I've seen these keys used in other embedded projects, for example that camera controller, CNC controllers, or cash registers.I find it hard to believe that a generic variant of these do not exist... All I have been able to find when searching Dome/Membrane/Silicone/Keypad/Switches/etc. were tactile switches/domes or those cheap Chinese membrane stickers like thishttp://www.vetco.net/catalog/images/VUPN6955-1.jpgTo be clear, I am not looking for those cheap Chinese keypads, but rather a solution that looks like a standard keyboard. Ideally it would come with keys, membrane pad, and key retainers, and would make contact directly with the PCB.If it turns out I can't find any from china, I'll probably just make my own molds and mill them myself. While this works (I've done some initial tests with resin and silicone casting), it's a pain in the ass to do, takes hours to machine, and I'd rather buy something pre-made. I thought I would check the internet one more time before committing hours to this.Thanks,Andrew

author: Andrew_K
author_rank: Contributor
timestamp: September 20, 2016, 11:42:47 pm
content: The cheapest I was finding was about $.80 a cherry switch without key caps. Are they cheaper somewhere else?

author: ataradov
author_rank: Super Contributor
timestamp: September 21, 2016, 01:46:35 am
content: There are push buttons like thishttp://www.ebay.com/itm/5-Pcs-Momentary-Tact-Tactile-Push-Button-Switch-12-x-12mm-x-10mm-4-Pin-DIP-w-Cap-/271497055911?hash=item3f367c4ea7:g:Pg0AAOSw3v5XItz1all over eBay. This specific one is just a random one, there are way better prices out there. Caps can be sold separately and they are available in a variety of colors (all with transparent cap).They are probably not as reliable as regular keyboard keys, but that is ok in many cases.

author: Andrew_K
author_rank: Contributor
timestamp: September 21, 2016, 03:49:12 am
content: Unfortunately my idea needs physical keyboard keys, like a computer would have. It's purely aesthetic, but it wouldn't sell if it used a cheap rubber button pad. Actually, this is for a prototype human interface device for computers... so that's why I'm being so picky. I want the final product to be nice.And I did find some cheaper Chinese version of the cherry MX keys. $0.30 per switch is a lot more reasonable than $0.85 on digikey or ebay. Still, I'd like to cut the cost as much as possible. It's likely this won't be as big a success as I want it to be, but just in case, I'm designing it with manufacturing in mind. This is a device that will need 20+ keys, and half the cost is already on the key switches. Not including PCB, which is why the standalone membranes are so appealing.I know they've manufactured them for other products... And they HAVE to exist generically somewhere... Just look at this picture I found:http://image.ec21.com/image/posprinterparts/oimg_GC06470592_CA06991740/Sell_Wincor_TA61_Keyboard_Silicone_Membrane.jpg.It's arranged in a square grid rather than a QWERTY layout, which tells me these are cut in to strips and used for smaller embedded applications.

author: ataradov
author_rank: Super Contributor
timestamp: September 21, 2016, 03:53:36 am
content: Quote from: Andrew_K on September 21, 2016, 03:49:12 amThen your problem solved. If product does not sell well, then keys will be a bit more expensive, otherwise, they are $0.47 @ 5000 pcs on Digikey.

author: dom0
author_rank: Super Contributor
timestamp: September 21, 2016, 05:44:42 pm
content: Quote from: ataradov on September 21, 2016, 01:46:35 amAlmost all of these feel awful.Cherry MX switches are imho the way to go here. There are companies that can print you keycaps with any labelling you desire for a reasonable price (e.g. wasdkeyboards), today you could probably even get away with 3D-printing your key caps.

author: ebclr
author_rank: Super Contributor
timestamp: September 21, 2016, 05:51:11 pm
content: 0.27 USD is good for you ?https://world.taobao.com/item/532654594774.htm?spm=a312a.7700714.0.0.B3vJbT#detail