Posted by BillS on October 01, 2009 at 19:34:01:
In Reply to: Timming relationship for tangential hobbing posted by Andy on October 01, 2009 at 11:43:50:
There are two motions required. As you mention, the cutter must advance at a known rate. Second, the workpiece index needs to speed up very slightly to track with the cutter. Of course, the hob shift motion must be syncronized with the change in workpiece rotation.
You mention a servo drive for hob shift, but is there also a rotary position encoder on the workpiece table? Is the table driven by change gears or another servo control?