Had a Supershop machine gifted to me, have very little information (diagrams, parts list) about this machine.
The chuck that came with it had square non self aligning, maybe designed more for metal work?
I purchased a 556212 Nova G3 Lathe Chuck Package self aligning chuck from Shopsmith.
I had expected it to fit, screw on easily, have the correct adapter.
When I remove the original chuck I have threads that have a diameter of about 2 1/4 inches.
The rod that enter from the left end of the motor unit and screws into the back of the chuck on the right side of the motor unit is about a 1/2 in diameter.
I am sure I have used incorrect terms and have not described the issue fully, but if someone has some help it will be appreciated.
You can go to this forum page and click on the red My Google Drive link just below the title. You'll find a folder on that page for FoxSuperShop that contains a manual and other information.
Is a self-centering chuck your goal? Is there some other reason to use the Nova chuck?
Before I broach other possibilities I see that the manual I indicated above points out that a screw center can be mounted in a collet chuck. I'm sure other centers can be mounted that way, and possibly a simple 5/8" secondary adapter you could make for the Nova chuck. I recall this has been done for using a variety of Shopsmith accessories on the Supershop. So, do you have the collet chuck that the machine had originally? Whatever you do with this machine you will probably want to acquire one if you don't have one now.
ETA: I have assumed you want to use the Nova chuck for wood turning. I do not think it has been designed for metal working use.
Mark V 510 with PowerPro headstock, Mark V Greenie with 510 headstock, Mark V 500 in progress
Sawsmith 2000 Ultra, 10ER in progress, 10ER undetermined future
https://cdn.shopify.com/s/files/1/1845/ ... al.pdf?149
And this post on Lumberjocks may be helpful, scroll down to comment #15 in particular
10ER #23430, 10ER #84609, 10ER #94987,two SS A-34 jigsaws for 10ER.
1959 Mark 5 #356595 Greenie, SS Magna Jointer, SS planer, SS bandsaw, SS scroll saw (gray), DC3300,