Collet chuck drawbar for ML7

I’m looking for some advice from anyone who has fitted a MT2 collet chuck to a Myford ML7 or similar. What solutions have you used when nipping up the bar at the non-workpiece end?

I was considering making a push fit plastic bushing to fit into the spindle hole in the gear train cover, in order to protect it, with a washer outboard and a nut on the end of the drawbar.

The drawbar for the Myford Rodney milling accessory has a simple steel bush to centralise the drawbar and bear on the end of the spindle. The drawbar will need little more than nipping up to retain a collet chuck, removing the chuck can be difficult if tightened enthusiastically. I would consider making an ejector that fits the spindle nose thread that will eject the chuck without having to strike the drawbar. The ER type of collet chuck that screws on the nose has the benefit of being able to still use the spindle bore to mount long work if you want to work hold and not just mount cutters.

Mike

Edited By Mike Poole on 29/05/2022 17:26:25

I used studding (threaded rod) with a top hat bush and a nut.

I have no knowledge of the operation of the collet chuck system used for repetitive work which I think the OP is referring to.

Robert Butler

Make a long top hat bushing so that it sticks out beyond the gear cover (easier to spanner the nut), also make the spindle portion about an inch long and a good fit in the spindle so it rotates nicely not wobbling about and setting up an unwanted vibration.

Thanks everyone - very helpful and enough to get me going.

I have an ER32-MT3 collet chuck on my Southbend lathe and use a simple drawbar to hold it. Made from a piece of threaded rod and 2 hex nuts. The nuts are locked together and the inner one is machined to locate on the bore of the spindle. Only light pressure is required to hold the chuck in the spindle and will release with a slight tap on the end of the drawbar.