Posted by Bill S on May 15, 2003 at 16:26:53:
In Reply to: SOURCE OF SPLINE LEAD ERRORS posted by Nick Miller on May 12, 2003 at 09:13:27:
Is the part broached? If so, and the broach is slightly tilted off axis, this would by itself produce a two-lobe (dumbell) pattern. Perhaps superimposing the lead error in the broach (which would have a distinctive pattern) over the two-lobe pattern could produce a heart-shape pattern. Just a guess...
In manufacturing, if the broach and holding fixture maintain the same relative orientation to each other, I suspect the pattern you see would be repeatable part after part.