Loose Chuck Check

[wcndave]

thanks for the advice, i have double checked and it's not bottoming out, however the register of the chuck may be slightly shorter than what chas called the locating collar, by just a hair... can't really tell...

 

[cambournepete]

Try putting a sheet of metal between the chuck and the shoulder when you screw it on.
When screwed on tight there should be no wobble.
A suitable washer would be best, but you're almost bound to have something you can try.
If all else fails thin MDF or even thick cardboard would do as a test.

Someone on the forum made me a washer for my Sorby eccentric chuck because it bottomed out and now it works fine.

 

[cambournepete]

I believe the grove in the locating collar is to allow a chuck securing grub screw to engage without causing any location disrupting burrs.
Why one would do that on a lathe that does not have a reverse facility as far as I know is a bit of a mystery unless the component is common across differing lathe models.

Because if you stop the lathe too quickly there is a danger of a heavy item spinning off.

 

[dickm]

FWIW, the Myford Mystro has a very similar arrangement to the pic of the Sheppach, although the register surfaces are bigger. From experience making an adaptor to fit a Bonham chuck to the Mystro (cheapskate!) getting the internal and external registers right is absolutely vital; the threaded parts are just there to hold things against the registers, not to give any precise location.

That is, exactly what Chas has said. And he's right about heavy things unscrewing - guess who "forgets" to tighten up the grub screws into the groove ?

 

[wcndave]

Just wanted to update that Peter from toolpost has been working with me on this every day, and been extremely helpful in every way.

We think that possibly the lathe register is just slightly too long, < 1mm perhaps, so the chuck does not go all the way on.

Getting a replacement body. If that doesn't work, I'll try a decent lathe!

+2 for good customer service from Toolpost

 

[CHJ]

........We think that possibly the lathe register is just slightly too long, < 1mm perhaps, so the chuck does not go all the way on.
.....

If that is the case, it would be a simple matter to make up a packing/shim washer to sort that out, we just need to know the diameter of the spindle collar and how thick you need it to be.