Monday, January 3, 2011

Building a longworth chuck

I have been meaning to make one of these adjustable reverse jawed chucks for some time.
I had been using the metal jaw extensions that fit my Oneway stronghold but find that it ties up the chuck too frequently.
This system is very simplle in design and works well _only if you follow directions to a T_ which I am wont to do sometimes.
As a result I now own a completely useless Longworth chuck body that is not close enough to operate smoothly.

From wood stuff 2010
The second one went much better and apart from a few cosmetic blemishes seems to work just fine.
I made this one with slots for 8 rubber stoppers instead of just 4 and it seems to snug the bowl down better.
From wood stuff 2010

I like to turn my work with a tenon on the base to conseve materail for the bowls so this chuck gives me more surface to remove and finish the tenon area.
From wood stuff 2010
Here I have trimmed off the tenon with a parting tool and smoothed the foot with a bowl gouge.
From wood stuff 2010
A bit of writing to help remember when I did it and the wood used.
From wood stuff 2010
The base is taped off to help prevent over spray from the lacquer used to sel up the base.
From wood stuff 2010

The unit is about 15-1/2" in diameter and will take a 14" rim.
The rubber stoppers are cane tips and should be avalible wherever geriatric supplies are sold.
Inside each cane tip is a wood dowel cut about 1/16" shorter than the tip height to give the tips some compression.
The back is 1" MDF and the front is 1/4" fir plywood.
The pan head bolts are 2-1/2" long and secure with jig handles.

Here's the test bowl removed fromthe chuck after polishing.
From wood stuff 2010

From wood stuff 2010
Cheers

Bob

2 comments:

David Shaffer said...

Very cool and it looks easy to build

Raul said...

"This system is very simplle in design and works well _only if you follow directions to a T_ "

What instructions?
Looks like both faces of the spiral slots are cut together in the same set up and one is reversed but how did you cut them?