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geekhack Community => Keyboard Keycaps => Topic started by: wolfv on Wed, 29 May 2013, 16:37:16

Title: How much clearance under a Cherry MX keycap?
Post by: wolfv on Wed, 29 May 2013, 16:37:16
I am designing a mount plate for Cherry MX and want it to fit most key caps.

With a Cherry MX switch in a flat mount plate, and the switch fully depressed, how much clearance is there between the bottom of the key cap and the mount plate?
In the picture below, it looks like there would be a 3mm clearance if fully depressed.
I suppose it depends on the brand of key cap.
Are there some key caps that have less than 3mm clearance?
(http://www.wasdkeyboards.com/media/home_banner/slider_1.jpg)
Title: Re: How much clearance under a Cherry MX keycap?
Post by: Findecanor on Wed, 29 May 2013, 18:33:21
Cherry keycaps have approx. 2mm clearance. between the keycap "skirt" and the plate.

These has to be some clearance for air to flow, or there could be a suction effect.
You will also have to take wobble into account. When pressed really hard on the edge, the edge of a 1.5u key will just touch the plate.
Title: Re: How much clearance under a Cherry MX keycap?
Post by: Photekq on Wed, 29 May 2013, 19:15:54
I don't fully understand why you need to know the clearance if you're designing a mount plate. Any mount plate will work with any keycaps. You can see on the Cherry MX specsheet (http://www.cherrycorp.com/english/switches/key/mx.htm) that the plate will always come in contact with the same part of the switch.

There aren't any keycaps that go beyond this point so there is no need to worry about clearance when designing a mount plate.
Title: Re: How much clearance under a Cherry MX keycap?
Post by: wolfv on Wed, 29 May 2013, 22:22:44
Thanks Findcanor.

Photekq, this will be plastic mount plate with ribs.  Letting the ribs come up a millimeter simplifies the design.