Bregalad wrote:
Sorry but why couldn't a simple elastic band solve the problem ? It's hard to say because I've never seen the inside of the FDS, but I'd try that.
Because the drive spindle/motor is the most finicky thing on the planet. The length of the band has to be exact and the tension of the band has to be exact.
You can't use a rubber band for a couple reasons: 1) it's elasticity is too high compared to the real FDS belt (which is a plastic-rubber belt that *does not* expand/contract when pulled), and 2) rubber bands are often square or round (when viewed length-wise or from a cross-section view), which means as the motors turn, the band wiggles itself off the drive spindle.
The drive does let you adjust it using a couple user-accessible pots, but in most cases touching those makes things worse. I'm not sure what the two pots control either, aside from drive or head timings.
I speak from experience. I had an FDS which I gave away (to Matt Conte). I initially tried repairing it using rubber bands + adjusting said pots, but the end result was failure or the rubber band working itself off the spindle after a few sections of operation.
I ended up just buying a working FDS off eBay and called it a done deal.