Eric Nelson
Lifetime Supporting Member + Moderator
Welcome to page 4...
You seem to have covered all the bases you can cover, short of detecting the part(s) DURING transfer, which I agree would be difficult. Monitoring motor current sounds like the best (or at least simplest and cheapest) solution, but you already knew that. Thanks to your "rambling", now I know that as well...
BUT... We build a LOT of "indexed motion" rotary assembly equipment (yours IS a rotary machine, right?), and have always relied on a mechanical clutch to prevent damage. When properly set, I would not feel too uneasy about sticking my finger in the works. Granted, I probably wouldn't do it ON PURPOSE! I'm just saying that a correctly sized (and properly adjusted) overload clutch does just that... Disengage when an overload occurs.
Although, on our rotary machines, we use barrel-cam style indexers (Camco, Stelron, etc.), so the cam provides the accel/decel ramps, NOT the motor drive. IOW, the motor continues to run at a constant speed even when the indexer is stopped (in dwell). Actually, I DO stop the motor during dwell, but the motor's accel and decel occur during dwell, so the load doesn't vary much. I'm guessing that yours is direct drive, so you wind up with very aggressive (IOW, steep) ramps? This would probably disengage a mechanical clutch during accel/decel because of the high inertia loads you achieve.
That said, I'll now shut up about mechanical clutches...
beerchug
-Eric
Rambling is good. You explained the process very well!... :nodi:Tim said:Ok,WARNING A LOT OF RAMBLING ABOUT TO TAKE PLACE
You seem to have covered all the bases you can cover, short of detecting the part(s) DURING transfer, which I agree would be difficult. Monitoring motor current sounds like the best (or at least simplest and cheapest) solution, but you already knew that. Thanks to your "rambling", now I know that as well...
BUT... We build a LOT of "indexed motion" rotary assembly equipment (yours IS a rotary machine, right?), and have always relied on a mechanical clutch to prevent damage. When properly set, I would not feel too uneasy about sticking my finger in the works. Granted, I probably wouldn't do it ON PURPOSE! I'm just saying that a correctly sized (and properly adjusted) overload clutch does just that... Disengage when an overload occurs.
Although, on our rotary machines, we use barrel-cam style indexers (Camco, Stelron, etc.), so the cam provides the accel/decel ramps, NOT the motor drive. IOW, the motor continues to run at a constant speed even when the indexer is stopped (in dwell). Actually, I DO stop the motor during dwell, but the motor's accel and decel occur during dwell, so the load doesn't vary much. I'm guessing that yours is direct drive, so you wind up with very aggressive (IOW, steep) ramps? This would probably disengage a mechanical clutch during accel/decel because of the high inertia loads you achieve.
That said, I'll now shut up about mechanical clutches...
beerchug
-Eric