Ignoramus6679 wrote:
Thanks to Steve's, he lent me a MT5 test bar. It fits into MT5 opening
in the spindle. My problem is that there is some sort of crud (or
rust) in it and the bar does not seem to be well aligned. So I would
like to remove that crud by some non-intrusive means, any ideas how I can do
it without runing the accuracy potential of the spindle.

Believe it or not, a sharp pocket knife will do a good job. Good
illumination and spotting blue dye is very helpful in detecting the high
spots. Clean both parts, and apply a VERY thin layer of dye to the male
taper. Insert lightly and twist a bit. You should get spots of dye on
all the high spots. Burrs can be gently scraped away with the knife
blade with little risk of gouging into the taper. if you have big rings
of galled metal due to spinning a tight arbor in the taper, that is
harder to fix, and may require just removing that entire ring.

You'd be amazed how much a few tiny dings will affect the seating and
grip of the arbor. Usually, though, they don't affect the alignment all
that much.

Jon