Tack welds for now.
Anyways, I have done a bunch of tinkering with design and the ball detent didn't work as planned, the main problem is weight on the bar that hangs off one side- We'll call it plenty of leverage (some scientific name for that).
I had to cut the welds off and weld up the 3/8" holes and start over. I started by asking my Dad for advice and he suggested cutting into the shaft in such a profile that a stop was drilled half way through the diameter on the shaft, for this I chose to drill a new 1/4" hole and sand it out with the dremel so that I could rotate the shaft to unlock the shield. I would use an exhaust valve for a hardened locking pin, I tried the square end for unlocking/locking that worked for the lockup, but to unlock all it would cause was binding, a rounded nose was required.
When I say hard I mean really hard as in dulls HSS cutoff blade per partoff.
The Pin

Spring was cut 1 coil at a time until I had the desired amount of pressure for my pin, basically the spring holds pressure on the pin while it is in the hole drilled in the shaft. Without a spring there is nothing to keep the pin locked and thus it could and would unlock during lathe operation which would cause the shield to fall on a rotating chuck.
In the one photo you will see the spring is up and the next it is down that is the lock up.


I considered making a manual unlock that I could reach around the back of the lathe for, but during setup that would be a PITA and I'd be altering it again in 1 week.
You wont see the 8x10 Lexan glass in any pictures, I have not done any work with the setup other than building the frame work for the glass. I don't really want it scratched so it stays off for now. I purchased a roll of Felt and some heavy rubber sheeting for the lathe bed, felt for wipers and rubber for chip/dust control on the ways, I use a heavy cotton comforter for a lathe cover it was free.
Thumbnails for now, click to enlarge.














This last photo is the mockup I will use for gaining access to the rear retaining ring so if needed this can be disassembled for whatever reason and reverse is as easy as take down.