[sdiy] Tonewheel questions

[James Patchell]

Sent May 27, 2004

         I would look into servo motors myself...if you purchase them 
surplus, they will cost a fraction of what a new motor would cost, and they 
do run very nice and smooth....

         One of the interesting things you will find is the interesting 
modulation you are going to get from the motor cogging.  I have seen this 
even using very precise three phase rotating magnet type motors...so, this 
is something to keep in mind as your choice of motor could end up defining 
your sound (which hopefully, in your case, would be a good thing).

At 11:50 PM 5/27/2004 -0400, Robotboy8 at aol.com wrote:
>I'm thinking of building a vastly simplified tonewheel organ.  What I'm 
>looking at doing is a fan motor running off of wall-current with a dimmer 
>(the kind used on house lights) to vary the speed of the motor (overall 
>pitch), this motor being connected to a shaft with 5 (or howeverman) 
>wheels.  My questions are as follows:
>1) Will the fan assembly work?  I know some fans don't 'like' lower 
>currents than they're used to seeing, what sort are these?
>2) Anything I should know about these dimmers beforehand?
>3) How many wheels is it reasonable to have on the shaft?  (As I said, I'm 
>thinking five, but could be swayed in either direction).
>4) It's mainly for drones, so a dimmer as pitch control isn't a problem 
>and no EG's shouldn't be a problem, but what about output level?  What 
>should the line-out level be?  And howsabout a 'to modular out' level?
>5) What's the cheapest sort of inductors to use?  I don't like the sound 
>of guitar pickups, they end up as a little more expensive than I'd like to 
>use.  I would like to have separate ones for each wheel so I can use pots 
>as 'drawbars'.
>6) Unrelated, but I have a keyboard labeled GC-7A.  It has no maker label 
>on it, and basically outputs a square wave with pitch determined by key 
>being pressed.  Ugly sound.  It has two 'timbre' controls that change the 
>sound - one seems to add tremolo, the other something I can't quite 
>identify.  It has an output labeled 'karaoke' but no line out, which 
>shares some solder with the 9v in (I run it from batteries).  I'm thinking 
>I may circuitbend it, but I can find no info whatsoever on it.  Anyone 
>have any clue?  Oh, and it plays a wide selection of obnoxious Christmas 
>melodies.
>(I got it for 2.50 USD from the thrift store.  Maybe if I didn't blow all 
>my money on crap like that I could afford the 100 dollar organ they have, 
>unlabeled maker but it has enough stops that it looks like fun).
>Any help much appreciated.
>        -eric

         -Jim
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