In case this helps someone else. I wanted to be able to fit the ER32 collet Chuck from my MW lathe onto my Axminster wood turning lathe. The MW lathe chuck uses a three bolt fitting with a 72mm register. My wood lathe is threaded M33 x 3.5.
I managed to buy a M33 x 3.5 backplate from RDG tools. The register had to be turned down by 1mm to fit and the mounting holes were also 1mm off the normal PCD. All easily altered.
I can now fit any of my four MW chucks on my WT lathe.
Sometimes it would be handy to do the opposite but I’ve not found a backplate with a male M33 x 3.5 thread yet …
