Drill Press Runout - Don’t get it…

[rons]

Any ideas? Is 0.0015 runout acceptable at the arbor? Could the rest be coming from the chuck or install method?

1. Draw accurate orientation marks on the top of the new chuck. Like a watch face.
Install chuck at different orientation marks and measure runout on outside of chuck.
If the outside runout changes then the tapered hole in the chuck is not that centered. Otherwise go to step 2.

Get a few new tapered shanks and some carbide grinding paste.
It's possible to correct the hole if you use iterative insertions with bluing, very light filing.
The first insertions should be in and out. When you get the runout low enough insert a shank and turn in a circle.
It's possible to use a tapered reamer using light pressure. But it would hit the bottom of the tapered hole and might have to be shortened.
At this point there is the expense of a reamer versus a new chuck.

2. Chuck the test pin and measure runout.
Concentrate on scraping metal on one or two chuck jaws.

It would be a hack if you just corrected a chuck jaw when the tapered hole is the real problem.
If the chuck ever comes off again it would have to be installed in the same exact orientation.

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If this was my job I would get or make a accurate tapered shank and use a lathe collet to hold the straight section.
Mount chuck on the taper and measure runout on the outside of chuck.
If there is unacceptable runout then the tapered hole in the chuck should be corrected.
Then mount a accurate test pin and measure the runout on the outside of the pin.
If there is unacceptable runout then a chuck jaw(s) would have to be scraped.