How small a centerdrill could you grind?
Jim
wrote in message
...
On Thu, 8 Jul 2004 20:06:39 -0700, " Jim Sehr"
wrote:

I used to work in a gear shop and had to repair gear shafts that had been
centerdrilled and had more then the .001 runout that the print called
for.
I used a steadyrest with ball bearing rollers and that gave me dead true
runout. It is best to collet or chuck on a small part of shaft and let
the
steadyrest pull the shaft to dead true. Then I hand ground a 30 degree
angled tool to form one side of the centered part. Imagine half of a
centerdrill without the drill part in front of the angle. If you blue up
the
center of the part you can see it cut the high point of the runout till
it
is dead on.

In the last year or so we've had to recenter several inspection
arbors. Basically the same, except after putting in the steady rest,
we indicated the compound to 30 deg., then ground with a Precice
grinder, small CBN wheel. Used the normal bronze against the arbor,
gives less runout than BB would.
Lennie the Lurker