Question On Aligning The Lathe Spindle And Bed Twist

[sanddan]

Did you ever try without the spindle turning, gearbox in neutral? I'm still thinking input shaft.

Jim, yes I did. Without the spindle running the shake/shimmy is reduced but still present. This was one of the tests I did when ruling out the chuck. As mass is eliminated the severity of the shake is reduced but not eliminated. Any ideas on how to check just the input shaft? I tried spinning the shaft with the pulley attached by using a drill and socket on the attaching nut but the drill induced it's own shake, too much transmitted by drill/socket. If the pulley PM is sending me doesn't help I might try truing up the current pulley I have. I'll have to make a mandrel to make sure the pulley is running true to the bore.

 

[JimDawson]

The only thing I can think of right off is to drive it with a drill through a vibration isolater (a piece of rubber hose). Maybe cut a socket extension in half and hose clamp a piece of air hose in middle. Or something along those lines, whatever you can do to get a soft connection in there. I drive encoders this way all the time.