[sdiy] About pots, and other things...

[Joe Grisso]

This brings up a question I've been looking for an answer to. Has
anyone found tact switch caps with built-in light pipes from anyone?
Even a simple transparent cap with diffused texturing on the top (a-la
the old M1 buttons) would be spiff.

Also, read below for comments regarding flight's queries...

-- 
Joe Grisso
Detachment 3 Engineering


On Tue, Jul 1, 2008 at 11:44 AM, flightofharmony
<flight at flightofharmony.com> wrote:
> 1) Has anybody here ever ordered custom pots or switches via
> Potentiometers.com? I've been looking at their Mod Pots, they have some nice
> options and the setup fee ($50.00) is pretty reasonable for modest
> quantities.

Haven't used these gents... I use either alps, alpha, or chinese
knock-off parts depending on the client's budget. GH electronic comes
to mind (you buy pots in 1K quantity, they end up being $0.15 each or
so)

> 2) Any recommendations on getting panels silkscreened? I'm looking for
> multi-color graphics with decent resolution, like the back panels on my
> Plague Bearers: http://www.flightofharmony.com/Plague_Bearer.html, for my
> upcoming Parasite model if possible.

Check your local YP for sheet metal houses. Call them, and ask if they
have any recommendations for a silkscreener. Some shops also have
internal painting and screening processes. The process will change
somewhat based on how you put your product together.

> 3) Theoretical musing (A.K.A. Has anybody done this?): Embed a small motor
> in a keyboard key for sensing velocity? I tested this out on some scavenged
> drive motors and a cell phone vibration motor and it seems to work nicely.
> Since the voltage induce in a winding is directly proportional to the
> velocity of the magnet's rotation, the generated voltage and/or current
> could be used almost directly. A scaling buffer would be all that is
> required to adapt the output to a given circuit. As a bonus, if the motor is
> large enough, it would also provide tactile feedback similar to the Moog
> keyboard patent which used magnets for that purpose alone. Upon release of
> the key, another circuit could provide a current to force the key back to
> the rest position - eliminating the need for springs.

Interesting concept, but it seems that it would be hard to tune,
expensive to build, and consume some power if a lot of motors were
'in-flight' at one time. However, I'm tempted by the haptic feedback
gained by using the motors. I've seen a lot of front panel designs
using hall effect sensors lately (the Studer Vista console series
comes to mind), and there were a few keybed designs using hall effect
as well. Ensoniq particularly comes to mind, since their keybed's
inductors were etched directly on the PCB under the keys. This is what
gave them both velocity sensitivity *and* poly aftertouch in an
economical package.

> I also fixed my website link below (thanks for catching that!)
>
> ~flight
> flight at flightofharmony.com
> http://www.flightofharmony.com
>
>
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