Myford chuck security

Myford ML7R

When trying to use rear parting tool and running the motor in reverse I found that the chuck was unscrewing itself off the headstock spindle. When fitting the chuck I lock the spindle by engaging backgear and then with the chuck key tighten the chuck on its thread as much as possible by hand..

How do I stop this happening so I can use the rear toolpost parting tool?

Mount the parting tool upside down and rotate in the usual direction.

Please do not engage backgear, you may well end up with a broken gear.

Does the ML7R have a pin (like the Super7) on the left hand face of the headstock which engages with the step pulley for the purpose of locking the spindle?

I exhibited a simple device at Sandown MEX which prevents the chuck unscrewing and which may well appear in published form shortly.

The ML7R does have a pin as KWIL describes, use that instead of back gear, it is much more positive ion use.

You could always fit a chuck lock of the type discussed in this thread when running in reverse:

Chuck Lock by Woofity

Similar chuck locks were supplied for their screw-nose lathes by respected companies such as Schaublin so they're not gimcrack devices. This assumes, of course, that your chuck backplate has a spigot 'neck'.

Incidentally, Woofity's version is a little more elaborate than commercial versions. The latter were commonly a simple split collar with a single screw spanning the gap (the strain relief hole opposite the split is still required, though).

Joe

Edited By joegib on 13/11/2012 06:55:12

Hi Trevor
As blowlamp says mount parting tool upside down

Nobby