[sdiy] Embedded micros

[Dave Magnuson]

At 12:23 AM 8/21/01 -0400, you wrote:
>At 10:58 PM 8/20/01 , Paul Perry wrote:
>
>>I look foward to any synth-diy posts whether they are analog, 
>>digital, or mechanical.
>
>Hmm...  Mechanical...
>
>That would include what? Making your own reverb plates and springs?
>Building one's own variable-speed-drill-powered, tonewheel oscillator
>synth? What else? How about a treadle-powered, mechanically bent and bowed,
>musical-saw "theremin"?
>
>Am I even close?  :)
>
>...but seriously, I DO agree with you.


Actually, I've been toying with a "mechanical" module the last few days.  I
have a motor from an old Laser Disc Player that conveniently works as a DC
generator.  It has a 3.5" diameter wheel attached to the top that I'm
planning to weight with lead-free solder for a little more inertia.  

Give it a spin one way and it makes a positive CV with a relatively slow
rise/fall time.  Give it a spin the other way, and it makes a negative CV.
I had it connected to filter cutoff, and it's pretty fun to play with.  I'm
just hoping that a little more weight on the wheel will make it "sustain" a
little while longer.  I may also add an adjustable slew rate limiter after
it to control the transients a little, and some sort of over-voltage
protection (so If I spin it too hard I don't whack my modular with a 30V CV)

The hardest thing is going to be cutting the panel to accept the wheel.  I
want the wheel mounted horizontally, so that only a cresent-shaped piece
protrudes from the face of the module... so I need to cut a 3/8" x 2" slot
in 1/8" aluminum.  Open to any suggestions for this.  Router with a metal
cutting bit?

Anyone try something like this?  Seems like a fun little project that's
going to cost me almost nothing for parts (The disc player was free).  Also
have a 680nM laser from it...  wondering what the heck to do with that
thing :)

Dave

Resonant Frequency:
resfreq at hoohahrecords.com
http://www.hoohahrecords.com/resfreq/index.html