Holding short lengths

The type of chucks with the jaws Rayond shows are about eg

**LINK**

with back plate fittings as well.

Not the above but some of the Chinese ones look very like the Bison's. Probably not SG iron though.

To be honest if the jaws are machined as I outlined and the lathe is up to it they are probably as good as mundane collets over a wide range of adjustment. The scroll needs to be pretty accurate to maintain the chucks run out. They can always be trimmed up.

John

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"The scroll needs to be pretty accurate to maintain the chucks run out. They can always be trimmed up.

John"

That is an excellent point, i am a bit of a T.I.R nut and i pride myself on being lucky enough to own a chinese chuck whose hard jaws consistently centre all stock to 0.03 maximum run out!I don't have a clue who made it but boy what a machinist, that guy/girl needs a promotion. I've used venerable colchesters with a whopping 0.2 runout 3 jaw!...And i think i'd be lucky to get that with home made scrolls? so i'll pass on that.

I am having a look at rotagrip.. and i know that my inside jaws can't hold much over 2inches and my outside jaws can do 5" at a push. And that number happens to fall lovely next to 125mm.. i can feel a wish list coming on. Thanks Jason, i never knew there was a jaw company out there, i take it they are reputable and make good on their word.

Michael W

Or these people who make them.

http://www.thame-eng.com/tecchuckjaws.html

**LINK**

No problems with using Rotagrip either from their website or their e-bay shop. They used to attend the shows but unfortunately no longer do so. They are not just a jaw company, sell all sorts of tooling of good to high quality.

Michael, If your chuck is a "no name " type you might struggle to find soft jaws for it. You could try the company that Jason mentioned. If no luck, the firm that JS mentioned or John Walton machine tools would make them for you but they are very likely to cost more than the chuck !! There are other ways to get over the problem [ if no soft ones are available ] that will give you soft jaws.

Rotagrip had them for both my "no name" and also my Bison.

The other options have been in the mags before and more than likely on here, just clamp to the standard jaws.

I do believe that, as there are alot of chucks about with the "80,100, 125, 160" sizes, but I look at the magazines for the register size and i really struggle to find any that have a register of 100mm, and that really puts me off my chances, as the 125 typical registers as a 95mm recess. Maybe theres hope. I only ever found 1 indian company that made a 100mm recess, perhaps the origin of my chuck.

Michael W

Michael, when you get a chance measure your chuck jaws [ accurately ] and pm me the dims. don't bother with the scroll dims.