I’m now working on a design of my first gasket-mount keyboard.
On a typical gasket-mount keyboard, what is the height of the gap in the gasket area of the keyboard case, and how thick is the foam used for it?
Any answer is appreciated.
Thanks!
Let me preface the follow information by stating that I have never designed a keyboard. This is just what I know.
You say “gasket-mounted”. To me, that means you have padded “gaskets” that keep the plate from touching any metal surface of the case with a friction fit. If that’s the case, It’s largely up to the designer on how much space they want above and below the plate. The main consideration would be having enough room below the plate so that no component or switch pins touch the bottom of the case when typing. The space taken up by the gasket pads depends on what type and thickness of material you are using. For instance, softer poron pads tend to compress to very small measurements as compared to a firmer substance.
Maybe you could start with a small gap for the plate mount on the top and bottom and then use different thickness pads to make up the space for the feel you want. I’ve seen a lot of cases use a thicker pad on bottom and a thinner pad on top, probably a consideration to keep the switch assembly as low as possible in the case. The poron gaskets I have encountered are between 2mm and 5mm. 3mm seems to be a popular middle ground. I don’t know what the compression thickness is, but I would say something in the ballpark of 1mm. Maybe the manufacturer lists the full compression size of the gasket? Perhaps you could research that?
Now, if you are talking about an o-ring mount, there are more concrete considerations:
From the top of the plate to the top of the PCB is 5mm. Most MX plates are 1.5mm thick. So, you are looking at a gap of 3.5mm.
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