Elmo ST-1200 HD Which pulley position for drive belts & do I need a shutter belt?

[Richard Seccombe]

Hi Everyone,
I recently purchased an exceptionally clean Elmo St1200 HD. It had not been used for a long time and every belt I could find was either missing or a gummy mess.
I ordered and replaced the drive belts. My first question is where do I place the long belt on the motor pulley? Based on the residue from the old belt it looks like it should be installed on the inner part of the pulley (closest to the motor). I live in the U.S. with 60 cycle power.
I need to purchase an upper take up belt as well as a counter belt and that install looks pretty straightforward.
My second question is whether I need a shutter belt? Looking on the Internet it isn't clear whether this model uses a shutter belt and if I need one, where does it go? There is a large balanced idler wheel in the lower left area of the projector (facing it with the cover off) that never moves regardless of where I turn the selector lever so I'm wondering if that wheel is somehow connected to the shutter (hence I need a belt)
Any information would be very much appreciated including instructions on replacing a shutter belt should I need one.
Thanks very much,
Richard

[Nantawat Kittiwarakul]

I once had ST1200, but that's been quite a long, long while ago - 20 years maybe. Therefore don't take this a solid reference.

1. Generally for 60Hz area, the pulley should be on the smaller motor pulley. That should compensate for the faster rotation speed of the motor.
2. If I'm not mistaken you'll need the second belt to to drive 24 fps rubber drive pulley as the main motor belt will only drive 18 fps drive pulley (or vice versa, I'm not sure).
3. That large idler wheel is actually sound drum flywheel for smoothing out film movement at the sound pickup. It will be driven by the film itself so it's not connected to any other mechanical parts.

This is as much as I can recall at the moment. If anyone else can think of anything beyond this, please feel free to chime in.

[Richard Seccombe]

Thanks very much. I appreciate it.