Posted by BillS on September 11, 2008 at 17:32:29:
In Reply to: helical posted by mike sakai on September 11, 2008 at 12:52:48:
Have you checked for machine play? Check the hob arbor endplay (should be practically nothing). Check the work spindle backlash. You should be able to torque the work arbor back and forth and see practically nothing on an indicator. Also, check the feed table backlash - especially if cutting action is climb cutting.
Also, an earlier visitor reported a missing keyway and slippage of gear on shaft caused "out of sync" cutting behavior.
When you say the hob is .005 thin, what does that mean exactly?