Harold and Susan Vordos wrote:

"Randy Replogle" wrote in message
...

wrote:
So yes do use the 4 jaw chuck and spend some time getting

it centered. before drilling each end. Dan


In addition, I'd cut the 60 degrees with a small boring bar rather than
relying on a center drill for accuracy.
Randy


I'm not sure I've ever read so much misinformation in all my years of
reading RCM. It is obvious, at least to me, that precious few of the
readers have an understanding of the subject at hand.

No, this is not directed at you, Randy. Your comments are spot on, assuming
the material is dialed perfectly, but even then it must be dead on center at
both ends.

Harold


Be specific Harold.

If you are going to swing the brush, you might as well be specific
about what you beleive to be bad information.

The test bar I made, is hardened, and ground on a tool and cutter
grinder of no real great trustwortiness.

I ran out of time to get it finished, and it has been languishing in
my toolbox since 2005, according to the dates I stamped on it's end.

It is parrallel for about half it's length, within a tenth, and then
suffers a slow taper down the remainder, to the tune of about a half
thou total. The requirement was to get within a thou, for the course, so
it was a passable grade, but I never did get it back on a machine to get
it back in line.

I claim no expertise, just the experience I had.

FWIW, for the class of work most guys need tools in their shops for,
they would be better spending their money on HSS cutting bits and
grining wheels, than a commercial test bar. If one is willing to put the
time into it, one can be made, but the usefulness is limited, compared
to other tools that could be made.

Cheers
Trevor Jones