Strange about the timestamp. I made the original post on Jun 13th, a month earlier. Perhaps there’s a glitch with the forum software.
Anyway, WRT the underlying question. I’ve attached an image of the MDR head. The dark colored knurled knob on the left allows you to set the angle. The silver knurled knob at the bottom sets a hard stop. Next to that you can see the point for the dial indicator. The distance from the pivot (silver nut on the black axel left of the label is roughly 1/5th the distance from the pivot to the end of a dop. To make the measurements I provided in the original post I put an empty dop in the collet and measured the offset with the dial indicator as I moved around the index gear on the quill. I listed the maximum offsets. With a little trig it’s easy enough to calculate the angular difference for that. If my math is correct the reported error would be approximately 0.06 degrees.
I’d love to hear either equivalent distance errors or angular errors (easy on an Ultra-Tec or similar) so I can make a comparison.
Thanks in advance.