Could definitely use conductive plastic for the bottom of the keycaps, the problem's that I just don't like the "feel" of most conductive rubber switches - I like the tactile switches a lot better, you can tell whether you've pressed a key or not! Some of the little "snap dome" switches are pretty good, I think research here would be good <G> Think centrifuges to de-bubble the mold; Works better than a vibration table, 5-6 G's does a very good job <G> In this tiny of a keyboard, there really isn't room for a spring in there, easily. Good challenge for time when I'm waiting for someone, with my family I get to do that a bit. Maybe a spring that is behind the PC board or something. Mark Bryan Andersen wrote: > Hi, > > I've sucessfully potted circuits in the 2 part plastic resin used > for making paper weights. (commonly found in better craft stores > or by mail order.) It takes laying them up in layers to get > anything with any volume, but it's dooable. Key caps would be > only one layer. You can also color the stuf, but I forget what > you use. I do remember one of the coloring agents sounded like > it would make it conductive. I never used the coloring agents. > For buttons you could make a mold and inject the stuf with a > large syringe (only good for one batch) or you could use an open > back mold and just pour it in then trim later. The stuf will > heat up some durring cure, but it isn't enough to destroy a chip, > however you don't want to run the circuit while it's still curing > as then you will be over temp. You must use mold release > compounds or mold materials it won't stick to. > > > I'm investigating potting materials, I suspect I could probably make, or > > teach someone else to make, custom key caps for this sort of thing in > > small batches, shortly. (Think, paste a letter to the "top" of each > > keycap with epoxy, then pot the rest of the cap - set the whole "plate" > > in a small centrifuge to remove bubbles - Grind the keys to uniform > > height; That sort of thing. Clear epoxy resins probably would do. > > Those who touch type wouldn't need the key caps, those'd be cheaper. > > Lot of hand work to do there!) > > -- > | Bryan Andersen || http://softail.visi.com | > | Buzzwords are like annoying little flies that deserve to be swatted. | > | -Bryan Andersen | -- I re-ship for small US & overseas businesses, world-wide. (For private individuals at cost; ask.) -- Subcription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" to
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