Since I bought this CNC lathe I've hankered after a collet chuck, which saves all the hassle of soft jaw turning etc. Problem is that the way chucks work on this lathe is rather unusual.
Most hydraulic chucks, be it collet or jawed, have a draw tube co-axial with the spindle which is pulled or pushed by a remote co-axial hydraulic cylinder. On the Beaver the chuck has the cylinder built into it, and has two ports (open & close) in the face of it's rear surface that mate with similar holes in the spindle nose where an O ring is trapped to seal the oil.
Now my main chuck is a Pratt-Burnerd 1749-02780 which I very much doubt was a special for Beaver so it must conform to some spindle nose standard (I assume). The lathe spindle 'seems' to be an "A2-6" standard spindle shape with the two hydraulic ports added.
Anything conforming to this standard is remarkably rare - in the last few years I've found one chuck like mine in the UK that the seller wanted really silly money for, and one rather beaten up collet chuck that was a fair price, but no collets and being in Canada transport killed the deal.
So when a collet chuck using this same system turned up on UK eBay complete with an almost complete set of collets I got quite excited. Conversations with the seller revealed that it was off a Beaver lathe - excitement raising to fever pitch - soon to be dashed when I find that it was off a Beaver TC10 lathe (mine is a TC20) that has an A2-5 sized nose so not directly compatible.
Explaining to the seller how limited his potential market was persuaded him to release it to me at a very reasonable price (£200 inc carriage) which is worth it for just the collets.
So LOADS of googling shows that at least two firms make a converter plate from A2-6 nose to A2-5 nose - they don't have the bores for the hydraulics but if the adaptor plate is fat enough there might be room for some drilling of oil galleries converting from the collet chuck's 60 mm PCD to the spindle noses 84.2 mm PCD. Both are 6 mm diameter.
I envision drilling blind holes into the two mounting faces of the adaptor at the two PCD's with a cross drilling joining them which can be blanked of with a sealed grub screw, but this depends on the adaptor plate being fat enough and actually managing to buy one!
Absolute 'back to the wall' solution is to make the adaptor plate myself, but it has rather a lot of precise features and needs to be absolutely concentric so not something to knock up in a wet weekend.
I have thoughts of 3D printing a model to prove the concept.
. . . the other issue is actually handling the original chuck - nowhere above to put a block and tackle and it weighs 47.2 kg
