[viroy]

I need to work on both round and square stock, the 3-jaw is very difficult to center square stock, so I'd like to go to 4-jaw.
Anyone know where to find one compatible with my rotary? not sure if this is special or if a lathe chuck will work?
Could also use some advice on replacing, I've never taken one apart
Chuck face is 4" diameter
I typically mill 1.5" square stock and 1" round stock

The translation gear is a:
Motovario
NMRV050



I found these on eBay but I dont know whats compatible:
https://www.ebay.com/itm/330720133144?
https://www.ebay.com/itm/352657616613?

[viroy]

I saw something that leads me to believe this is possibly a K11 chuck and that I need a K12 chuck?
The biggest difference I notice is the thickness, the jaws go right to the edge of the backside... but all the others I see for sale are way way thicker.
Man why is it so hard to identify this and find a replacement

This is the only marking on the chuck