On 8/15/2015 11:59 AM, Chuck Guzis wrote: > I went and stared at some of my 8" drives for a bit this morning. > > It occurs to me that if your top guide frame is laterally "warped", the > centering of the hub clamp assembly won't work.
Agreed. But the darn thing is cast, with lots of fillets for support. I wonder how it would ever get warped, short of something REALLY heavy being dropped on it, or it itself being dropped from a considerable height - and there is no evidence of that. However, I thought I would test an SA 801 (jumpered as an SA 800) on the thing, so I could test the controller at double density. When I did that, something died (smelled electronically burn-y) after a few seconds of OK operation. Not sure if it was one of the tantalums or the stepper or something else, though. Anyway, I now have a drive that I can pull the clamp arm out of (the top guide frame, as you say) and try in the failing drive, to see if I can nail it down to that part of the spindle, just out of curiosity. > > If you've got a wiggler gauge handy, you may want to see what the > deviation is when the hub clamp mates with the spindle hub assembly. > While you're at it, you may want to check the spindle hub itself to see > if it's not out-of-round. Don't have a wiggler gauge, or anything to use it with. > > There's a patent 3,898,814 on the Shugart clamping system that many > manufacturers licensed. Perhaps it can shed some light. > > --Chuck > > > >
