One-off conductive rubber keypads?

F

Funky

Guest
Is it possible to buy conductive rubber keys individually or as a 4x3, 4x4
etc set. In particular, like the small keys on the portable Dataman
programmer or a calculator.

Thanks,
Funky
 
Why not use part of a tossed out PC keyboard or for that matter a new one.
Around here I can buy new keyboards for $10C. Easy to hack the section you
want....
j
 
Yes, the keys are easy to get, the problem is that you need gold plating on the
pcb.
 
On 16 Mar 2004 23:55:55 GMT, the renowned cbarn24050@aol.com
(CBarn24050) wrote:

Yes, the keys are easy to get, the problem is that you need gold plating on the
pcb.
Or graphite/carbon ink printing.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro Pefhany wrote:
On 16 Mar 2004 23:55:55 GMT, the renowned cbarn24050@aol.com
(CBarn24050) wrote:


Yes, the keys are easy to get, the problem is that you need gold plating on the
pcb.


Or graphite/carbon ink printing.
For the last week I have been testing some Caikote44 conductive coating
on my home brew membrane switches over plain 2 oz copper grids. Rigged
a test stand with an old 1 RPM clock gear motor and a spring. At about
9,750 presses at this instant and it is still working OK. According to
the 'scope I am getting a bit more bounce than a week ago but still
acceptable. Resistance is starting to rise but it is still under
0.5Ohms. I am expecting it to rise sharply or maybe short out sooner or
later as the stuff flakes off but so far so good.

The down side is that the Caicote44 is probably the messiest stuff I
have ever worked with and that includes the marine adhesives I work with.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com
 
On Tue, 16 Mar 2004 20:29:42 -0500, the renowned Glenn Ashmore
<gashmore3@cox.net> wrote:

Spehro Pefhany wrote:
On 16 Mar 2004 23:55:55 GMT, the renowned cbarn24050@aol.com
(CBarn24050) wrote:


Yes, the keys are easy to get, the problem is that you need gold plating on the
pcb.


Or graphite/carbon ink printing.

For the last week I have been testing some Caikote44 conductive coating
on my home brew membrane switches over plain 2 oz copper grids. Rigged
a test stand with an old 1 RPM clock gear motor and a spring. At about
9,750 presses at this instant and it is still working OK. According to
the 'scope I am getting a bit more bounce than a week ago but still
acceptable. Resistance is starting to rise but it is still under
0.5Ohms. I am expecting it to rise sharply or maybe short out sooner or
later as the stuff flakes off but so far so good.

The down side is that the Caicote44 is probably the messiest stuff I
have ever worked with and that includes the marine adhesives I work with.
Impressive. Not so much the results, but the fact you've made your
membrane switches and are actually testing them. I've seen companies
ship (mumble) units without any such spadework.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro Pefhany wrote:

Impressive. Not so much the results, but the fact you've made your
membrane switches and are actually testing them. I've seen companies
ship (mumble) units without any such spadework.


They have no excuse for not testing. It is not hard or expensive. My
"test stand" is a motor salvaged from an alarm clock that my teenage
daughter sent to eternity one morning, a spring, a hand cut plastic cam
and a chunk of neoprene mounted on a piece of plywood nailed to a 2x4.

If you think about it, membrane switch makers are just printers that
found a high profit way to use their equipment. I think if I could find
some really good UV resistant ink compatable with adheasive backed vinyl
for my inkjet I could produce some really professional switches. I'll
know better in a few weeks when I hit 40K cycles. :)

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com
 

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