Quote:
> ...and (sneaking in quickly before Robert Bastow gets there first <g>)
> in any event, if you want the most accurate results, you machine the
> centre *in situ* to make sure that any spindle runout & any runout in
> the original machining of the centre are of no consequence.
I thought, and I am probably wrong, that the ends of the centres are
case hardended and then then very finely ground to remove any
irregularities. Or. That the end was hardend and tempered to take the
load and wear put on the end, to machine the centre would require the
thing to be annealed? and then machined and then hardend and tempered
again, each time removing the centre from the machine and refitting
would this not loose the accuracy of placement?
I understand that a centre fitted in to the headstock need not be as
hard as it would rotate with the work and therefore not have the
friction, but syill needs to cope with the pushing away from cutting
tool load.
This is getting to deep, the main problem that brought this to me, was
when fitting a centre to the tail stock and checking alignment with
centre in headstock, I noticed dfferences between centres, this led to
the tests.
--
Cheers Adrian
by