Turning Archive 2007

Reversing VS lathe without stopping

JohnKJordan in East TN
>I use a Jet 1642 variable speed lathe. I always let the lathe stop completely before throwing the reversing switch, but the other day I accidentally hit the switch (don't ask how) and instead of a disaster the lathe gently slowed down then reversed.

I got to wondering if that was an acceptable procedure. It's obvious that instead of simply coasting down when switched off, the speed controller obviously decelerates the lathe to gradually slow it under power (just try to stop it with your hand while it's slowing down) and gently ramps up the speed when switched on.

If I were writing software the for the controller, that's certainly the way I would do it to minimize stress on components and help keep chucks from locking up or loosening on the spindle threads. It only makes sense then that the same algorithms would provide for a gentle speed reversal.

Does anyone know for sure if switching direction under power is a safe procedure for these lathes? It would sure save some of time.


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