I needed to use a 3" three jaw chuck on my mini lathe, so I considered making a backplate for it, however the PCD for the holes for fixing it were not in a favourable place and would have needed a much thicker piece of steel and adding extra weight, plus more over hang. So I decided to make an adapter to accommodate the screw threaded backplate that the chuck was already fitted with.

Having looked among my various collection of scrap and offcuts, I found a piece of scrap ram rod.

This needed a slice cutting off the end that can be seen, which was a fair trial with my Warco 220 lathe with a parting blade sticking out quite a lot for its size.

This was then faced and a register to suite my mini lathe and a PCD for the fixing hole was made.

It was then turned end for end and parted deep enough for a hole saw to leave a stub for the screw on chuck.

It was then faced and the stub turned close to size and a hole drilled through the centre for an M12 thread.

Then it was fitted to my mini lathe and finish turned and faced to size and then moved to my Boxford lathe for screw cutting the thread for the screw on chuck and the centre hole was tapped M12 and then fitted back onto my mini lathe.

A M12 bolt with a suitable length of plain shank was screwed fully home and the head thinned from the underside of the head, the head was then faced and turned to 16mm diameter and the shank was filed flat on two opposite sides just on the underside of the head for a M10 spanner, this was to make a backstop for the first job for the chuck.

This light weight 6" four jaw screw on chuck can also be used on this adapter.

Regards Nick.