Scott's Atlas / Craftsman 101.07403 12x36" Lathe, modifications and projects. Stone Mountain, GA Unique Visitors:

Start with some 1.75" stock (2" would be better.)

Turn section to fit in the narrow part of the T-slot.

Note: stock has a hole already drilled way off center. When using a steady rest, the stock wants to "walk" out of the chuck, so a center was needed. I had a piece of aluminum between the dead center and the stock as I could not use the hole.

I would also have drilled and tapped it first but waited until later.

Note: you don't want any radius in the corner. That will cause the nut to try an pry the T-slot apart and possibly crack it. Easisest is to move the bit farther into the corner. In this case it was ground off later and was a pain to do.

Part near completely parted off. I did start a part groove sightly behind then did the full cut at the desired thickness. That made it a bit easier to get cutting fluid in and chips somewhere to go.
   Test fit for thickness of disc. Flipped over, the stub fits in the slot. Note stud is too long at this point.
 

 I mounted the part in the 3-jaw and faced the stud until the height was just less than the upper part of the T-slot. You do not want it touching the tool post.

Then I bored a hole using a milling bit. I had to use a mill bit as the hole in the stock was about 0.100" off center.

Picture is tapping the nut for the 7/16 bolt used on the tool post. Note, I'm using the live center to keep the tap straight.

Tapping was done by hand by locking the spindle (back gear with pin in) and turning by hand while keeping the tailstock snug.

 

 Last step is completely manual. Clamp in vice and "cut the ears off". ;)

I roughly scribed 0.2" outside the stud and cut with a hacksaw. It was snug so I did a bit of grinding with a die grinder and then a file to fine tune.

All it needs is a bit of cleanup to remove rough edges and chips.

Finished part