I installed my step jaws on my Talon chuck.
Photo #5: Step jaws installed.
I mounted the blank on the chuck by expanding the jaws inside the hole.
Photo #6: Blank mounted for sanding inside the holes.
I was then able to sand inside the holes to remove any marks left by the sawtooth bit.
Photo #7: Sanding the holes.
I rotated the piece to grip on all four holes and sanded about half way in to the centre on each mounting.
Photo #8: Faster shutter speed.
Alternatively, you can use a 1” drum sander mounted in an electric drill to sand the interior. That is faster and keeps your fingers out of harm’s way.
Photo 8b: Sanding with drum sander.