On Fri, 8 Mar 2002, Tony Firshman wrote:
> 1) Keybounce. They produced a replacement 8749 to 'cure' this, which it
> did. Unfortunately it killed ser2 (8-(# Hermes/superHermes have cured
> key bounce with all keyboards using the pcb connectors.
> 2) The pcb was sub-standard, and the 'gold' plated contacts weren't.
> After maybe 5 years, all the contacts need cleaning - quite a major
> dis/re-assembly job
There's a lot of incentive to have poor or false gold contacts - having a
large PCB like that plated will more than triple the cost of the PCB. I'm
looking for a way to do quality 24K gold plating in-house - it looks like
it will cost a few hundred dollars to buy the equipment, and a couple of
days practice and training to learn how to use the equipment properly.
> 3) The ribbon cable was soldered each end, and fractured very easily
My design will not have soldered ribbons. It will have IDC cable and
connectors, for simple re-usability.
> 4) The thin pcbs weren't thin enough and ruined the connectors for std
> membranes
The trick to this was to stick a couple of layers of tape to the back of
the ribbons to make them thicker. However, my design will have thin pins
which enter the two sockets.
> Careful with your design (8-)#
Well, designs. I have three different designs on the go. The one which
looks to be technically most robust(40%), subjectively most comfortable
(30%) and economically most viable (30%) will be the one that gets
produced.
Unfortunately, none of them are completely straightforward, from the
component manufacturing or availability standpoint.
Dave
ql.spodmail.com
