I have a Jet 1340 metalworking lather which I have adapted for woodturning. I bought a Supernova 2 chuck with 2" jaws for it. At first use, when I tightened the jaws, the key would come to a sudden stop, not a gradual stop. So, I took it apart to looks for burrs, chips, etc. There was a burr on the channel for one of the jaws, cause by a hard impact against the chuck body, but it interfered only when the jaws would be closed to about 3/8" diameter. The instructions from Teknatool say to lube the scroll ting (is that a misprint) and the pinions generously. I did.
I didn't see any other burrs inside, but I was very surprised to see that the ting (ring?) and pinions are cast parts, not machined. As castings, they are pretty nice. Is that the $200 difference between the Nova and Vicmarc?
I also found a larger 5/16" T-handle hex wrench which enables a tighter grip on the wood, unlike the suddern stop observed earlier.