Scoll Chuck - worn out ?

[Rocky5]

I recently upgrade by wood lathe which included a 100mm Bonham scroll chuck . Ive used it a dozen or so times and seem to have trouble with bowls and spindles getting out of round or coming loose. The chuck seems to have had a tough life with a few bits machines off ... Lathe runs true not sure about the chuck...

I rang around and couldnt find anyone who sold the Bonham - no longer I suspect..

I want to turn large bowls and plates eg 500mm plates and 300 inch bowls

How do you tell if a chuck is cactus ? I know with metal chucks you can change the jaws ..would the slides and screw also be worn.

Randal

[hughie]

I want to turn large bowls and plates eg 500mm plates and 300 inch bowls

300inch, maybe the chuck ain't up to it......dunno what chuck would be.


Typo, I hope, 300" is 7.6m or there abouts, might qualify for the Guinness Book of Records.

[Jim Carroll]

The Bonham was a copy of the Nova chucks so the nova accessories will fit.

The only thing you have to do is get a set of nova screws as well.

To do platters all you would need is the 100 or 130mm bowl jaws

[Rocky5]

Jim and Hughie

Thanks for the help, solved the mystery. Yep think Ive set a world record ..should be 300mm

cheers Randal

[issatree]

Hi Randell,
Yes as Jim said, you just buy more Jaws + Screws. The other thing it may need is a bit of a clean. Give it a blowout with a A/Compressor then leave it Submerged in either Petrol or Mineral Turps for as long as you can, say 2 - 3 days.
It has most likely never been cleaned.
Dry it off with the air again, & if you can't get it undone, then just squirt Graphite Powder into the Chuck. Not a good idea to use CRC as the dust will just clog it up again.
Find 2 Screwdrivers, the same size as the holes in the Chuck. Cut the ends off the S/Ds & leave the shanks 5 - 6in. long, now sq. the ends up on the grinder, but don't round them off, just leave them sq. Also, think about boring 2 more holes in the body, makes one heck of a difference, with 4 holes. When you remove the Chuck from the Lathe, put the knockout bar across the jaws, then you won't wear out the small body holes, & it is much easier. Tht's my 2C's worth, hope it helps.
Regards,
issatree.
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[rsser]

IME jaw mounts or the slots they're in can wear.

Not by much & this is by no means the main source of run-out or grip loss.