06-17-2016, 08:15 PM
(06-17-2016, 05:56 PM)ronboult Wrote: Hi Highpower thanks for the suggestion.
I have considered that option but was concerned that the drawbar threaded hole may be a loose fit and not concentric with the arbor.
If I turn the centred plug between centres and make the thread slightly oversize it might work.
I have no idea of how concentric the two shanks of a face mill arbor should be, but thought it should be in the order of tenths. I expect that such arbors are always ground on the same axis.
I was thinking in terms of single pointing the threads to only cut them enough to get a good close fit. Then after the plugs are screwed in, dial in the collet mating surfaces in a 4-jaw and then drill your centers. You could then spin the collet between centers by hand to see if the outer surfaces are running concentric before you make any cuts.
Sounded good in my head anyway....
Willie