Let me guess, you saw this in a Mr. Pete video. I just drew the 2" up the other day. It is 90 percent done. It is a 4 step item. Starts as 3" Square X 1-1/2 thick. Step 1 is 8 sides at 90 degrees. Step 2 is 8 sides at 45 degrees. Step 3 is 8 sides at 22.5 degrees. Step 4 is 6 sides at 60 degrees.
I am not building this!!! See below.
I decided to go with 4 set screws. That way I can center the round in the index. I also drew up the Joe Pi gauge that glues to the front of a round object. He makes a point that the gauge doesn't have to be perfectly centered and playing with the drawings he is right. The reason for 4 pins is so that once the round is in the gauge, whatever you use to locate it with will be very close as you spin it around. The original works like a lathe dog. Put a one inch in a two inch hole and you have to alter the blocks or parallels between 1 and 2 inches in steps. With 4 screws and good eyes, you can easily get .030 or less which makes the setup quicker.
This is a work in progress, so it has been changed as follows: Step 1 combines the first two steps above. 8 sides at 45 degrees. Just doesn't make sense to duplicate the angles. Step 2 will be 8 sides at 22.5 degrees. Step 3 will be 6 sides at 60 degrees and step 4 will 5 sides at 72 degrees. The first step will be 1/2" instead of 3/8" so that makes the starting piece 1-1/8" thick.
Just my 2 cents. This is next months project.