Edge Tailstock Alignment Bar

Some time ago I made my own test bar to use the variation of RDM suggested above by RJSakowski. My center drilling was off by about a half thou so I use RDM to correct for this. In addition, there are a couple obvious ways setup errors could affect this measurement so I check for them too - it's easy once the test bar is available, see:
http://www.gadgetbuilder.com/Lathe_Align.html#Tailstock_RDM_Align

John

I've learned many times that tailstock alignment is only repeatable at the quill position used for determining alignment. You have to own an unworn high end piece of machinery that is properly setup to be able to run the quill in/out from it's verified position to expect any reasonable precision in other positions. Only way to get close to absolute zero that I know of is to turn round stock at the same quill position that will be used for the work piece...hard to do with a prefab'd test rod.