[sdiy] vako orchestron

[Gene Stopp]

Howdy,

I have experience getting busted Orchestrons back to a working condition, however I don't have experience with a dual-manual version. I think it's safe to say that the Orchestron is quite the mechanical challenge, much more so than a Mellotron for example which is pretty straightforward. The last one I resurrected had a non-turning thingey too, the cause being that it sat for so long that the rubber drive wheel got a dent in it from resting on the motor spindle, and just sat in the dent as the spindle turned (causing the dent to get bigger, of course). I managed to extract the wheel on its shaft, and then chucked it up in a drill and spun it while filing away at the perimeter until the dent was gone. This of course made the wheel diameter a little smaller, but that's OK since the motor spindle is a conical shaft and the pitch adjustment (which moves the spindle along the drive wheel to catch a bigger or smaller diameter) had enough range to make up for it. If the dent is too deep, the wheel diameter may have to taken down to the point where the instrument no longer is in the proper pitch range, which would be a non-reversible error.

The removal of the wheel and shaft was a dicey operation in itself, with lots of bending of metal and nylon parts to what seemed to be almost the breaking point. A mistake in any part of these procedures would result in a broken part, and the prospect of finding a new part is daunting. The chassis and drive assembly may be identical to that of the Optigan, a fairly rare but not impossible-to-find beast. One could sacrifice an Optigan to get an Orchestron running I suppose, which would be somewhat of a shame (Optigans are very cheesy, so cheesy that they're cool IMHO).

Did both drives go out at the same time? I assume they're duplicate assemblies on the dual manual version (i.e. two Optigan chassis) so it seems strange that both would go out at the same time, unless it's the sit-for-too-long syndrome. But then again maybe they're linked somehow...

Anyway diving in to an Orchestron takes a kind of a go-for-it attitude tempered by a feel for what is safe or reversible. It would be difficult to advise what action to take without knowing more. Are the motors spinning? (Maybe they're fused and the fuse blew) If the motors spin, are they contacting the drive wheels? Another thought, perhaps it's a mechanical problem in the engage/disengage linkage. If the motors spin and the drive wheels are resting against them, are they still because they're stuck in a dent? I'd be happy to advise if you could narrow it down some.

p.s. I know now where to find spare light bulbs - Vons!  :)

- Gene
  ----- Original Message ----- 
  From: SRRecords at aol.com 
  To: synth-diy at dropmix.xs4all.nl 
  Sent: Tuesday, December 21, 2004 6:52 PM
  Subject: [sdiy] vako orchestron


  Hello all.

  My Vako Orchestron is not working and I was wondering if anyone could supply some help.  It lights up etc., but on both manuals (i.e., keyboards) the "thingies" inside do not spin, and thus no disk would move were I to put one in.  I'm not a technical expert, but if someone can help get the parts a'movin, then I might be able to save my beloved machine.

  JMask
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