That Workstop Device That I Mentioned

 I built it.

It uses T-nuts to hold in the T-slots of the table.  Two 1/4"-20 thumbscrews control X and Y of the 3/8" steel rod that allows me to get every workpiece in the same position.  This lets me avoid using the edge finder each time.  Also, if I am trying to cut two pieces to the same length, I can cut one to length and be sure the next one ends up the same length.

On the first try, I for reason that I can remember decided to use 2" long 10-32 thumbscrews.  (The Sherline's standard T-nuts are 10-32.)  That was way too long.

I ordered some 1" long SHCS screws and they were a little short for a 1" thick block, so I couinterbored the top of the block 0.3" deep and that was just enough.

If you look carefully, you will notice the two steel rods are flat on one side.

This was partly to have a flat surface for the thumbscrews to grab.  This reduces rotation and also allows me to keep the various parts at right angles.

The bottom block has a 3/8" hole milled .75" deep into a 1" thick block and a tiny setscrew locking the rod in place.

Why does the hole seem to be countersunk?  I tried to mill at too high a rate and the acetal melted into a blob that excavated a molten hole.

What's left.  The top block should be wider so the horizontal bar is more centered in the mill vise; the top rod should be longer to handle workpieces farther right in the mill vise.

Milling the flat on those steel rods was slow, especially compared to acetal.  But I wrote some gCode to remove .01" per pass and just let it run unatended for several hours.  It ran to completion just fine.