If using a collet mounted stop, be aware that the seating depth of the collet will vary with the amount of force used to close the collet. Joe Pieczynski did a great video on the subject.
A better strategy for repeatable precision lengths is to use a stop fixed to the spindle. That way the part is referenced to the spindle and therefore the lathe bed. Here was my answer to that.
I have used a part stop in my old Craftsman lathe headstock for many years. When making multiple parts, it provided accurate positioning of the parts in the chuck and it allowed removal of parts for measurement when machining to precise lengths. When I bought my Grizzly G0602, I really missed...
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