At 01:02 PM 11/08/2010, you wrote:
>I want to be able to robotically press buttons on a cell phone.
>This means the throw of the button press will not be more than 5mm.
>I have seen mention of buttons requiring 21 pounds of pressure.  So

21 lb is crazy. Normal spec for this construction of keyboard is
around 50-300 grams(-force) , and I expect towards the lower end for
the tiny cell phone buttons. I have a sample that illustrates
capabilities kicking around somewhere and I'm sure it doesn't go
over 500gm-force for a big fat key.

>far intergoogling has not revealed consistent data.
>I want a solution that costs ~$2 per pressor. ( I can dream )
>
>One thing I am considering is some kind of doo-hickey using nitinol
>wire.
>Any suggestions or sources of button pressors ?

Hobby servo? Integral driver & you can control travel and actuation
speed, for around $10/key. You'd need to make guided wire linkages
and pusher pads for each key (drill press and pliers would most
likely suffice for tools).

>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the rewar=
d"
speff@interlog.com             Info for manufacturers: http://www.trexon.co=
m
Embedded software/hardware/analog  Info for designers:  http://www.speff.co=
m



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