Neil, you're closer to the source. This chuck is not listed on the Teknatool web site. Don't know what's going on.
Yes, Peter, I'm closer to the source and bought mine back when they first came out.
I have the original 5" Supernova Deluxe with two screw holes on the slides that took the 5" dovetail jaws and the 5" Powergrip. I then got the first Titan chuck with the three screw holes in the slide to take the Powergrip with three screw holes. Both of these chucks were designed to take a thread adaptor insert to fit on various lathe spindle thread sizes. Both the 3 screw hole Titan and the 2 screw hole Deluxe took any of the other smaller Nova jaw sets. All are interchangeable.
Because of the image quoter, I'll upload those in a separate post.
The later Titan II & III came with dedicated spindle threads in the body of the chuck, but only in a limited number of sizes, which, as far as I know, never included the 30m x 3.5 spindle thread size that is most common down here. Besides being incompatible with our most common spindle thread size down here, the two screw hole Titans models seemed to me to be a backward step and never made any sense to me.
IMO, the Deluxe and original Titan were an excellent step up from their SN2 and won over the Vicmarc chucks on jaw compatibility across its full Nov jaw range, whereas Vicmarc has that annoying apartheid between its regular and larger chucks.
In defence of the larger Vicmarc VM120 chucks, they may have that annoying jaw and screw size incompatibility with its VM90 and VM100 chucks, but the VM120 jaw size range goes way above the 5" provided by Powergrip jaws for the Titan.
The original Titan is an excellent chuck and I have swung some very large chunks of wood off them.

Disclosure: I have and regularly use half a dozen of both Nova and Vicmarc chucks. I don't think one is better than the other and am equally happy with both...
