Longworth Chuck

[Mike Henderson]

I was browsing the older posts here looking for information on vacuum chucking and found a reference to a Longworth chuck. I googled and found an artcle on making a four jaw chuck here (http://www.fholder.com/Woodturning/lwc-wtm.htm).

But then I remembered that the perimeter of a hexagon is six times the radius of a circle scribed just outside the hexagon. So to lay out my six jaws, all I had to do was use dividers and scribe a circle, then use that setting on the dividers to lay out the six segments - very simple.

To route the arcs I used a circle jig by MicroFence. Very nice product - worked very well. I also reversed the type of material recommended in the article. I used 1/4" MDF for the face and 3/4" plywood for the main part of the chuck. I did this because I felt plywood was stronger than MDF.

I haven't put a bowl in the chuck yet but the chuck operates very easily and smoothly. I'll be interested to see how it holds a bowl for finishing the foot.

If it hadn't been for this forum, I'd never have known that a Longworth chuck existed.

Mike

[Jerry Allen]

Thanks for the photos, Mike.
I made one a few months back and used a 1"-8TPI nut on the headstock end.
That was before I bought a used Jet 1236. I was dismayed to learn that it would hit the motor. Fortunately I still have my Jet Minis and have still been able to use it.
After seeing your photos, I may try to use a faceplate and spacer. My only concern is getting it centered as well as it currently is.

My only comment about yours is that the rubber parts seen a bit small. They should work okay with a straight edge or bowl with a slight lip turned outboard, but you may find a piece a little tough to grab depending on the object's shape on the clamping end. I used white cane tips from HD. I emphasize white rubber because I used to use a Nova Cole chuck which had black rubber that used to leave marks on my work that was difficult to remove (what were they thinking) I think they were 3/4", maybe 5/8", I.D. They have a dowel inside that is not quite the length of the blind hole in the cane tip, so when tightened, they expand some. This has allowed me to grab bowls and forms which otherwise would have been impossible. The reach is about an inch long and there is a lot of rubber to grab the form somehwere within that area.
I still have had to use the tail on occasion, but rarely.

Anyway, congrats on a nice job. I'm sure you will find it useful and indispensible.

[Mike Henderson]

Jerry - thanks for the comments and the suggestion about the rubber parts. I thought they were small, also, but had problems finding something that would work. I'll look for those cane tips at HD.

Thanks for the suggestion.

Mike

[Jerry Allen]

Mike,
Info and pic (see the .pdf also) in this thread:
http://www.sawmillcreek.org/showthread.php?t=63893


Home Depot-Shepard 89118 in hdwr dept

Also see some comments by Joe and Wally on the 2nd page

[Steve Schlumpf]

Looks like a real nice chuck Mike! Let us know how you like it once you get the chance to use it. Looks like it should work great!

[Mike Henderson]

Jerry - I went and bought those cane tips that you recommended - much better than what I had before. Thank you very much for the recommendation.

Mike

[Jim Becker]

Very nice work, Mike! Do remember that this kind of thing is for final finishing cuts...not hogging material. In fact, it's still a good idea to bring up your tailstock as you pair down a tenon and only depend upon the chuck for removing the final nib, some finishing cuts and any sanding in the foot area. (I do that even when using a vacuum chuck for the same reason...to eliminate the chance of the turned object, umm...disengaging...from the chuck and flying around the shop all by itself)

[Bernie Weishapl]

Ditto what Jim said. If you take to big a cut it will sling the bowl right out. Keep the tailstock up till the last minute. Great looking chuck Mike.

[Mike Henderson]

Thanks for the advice, Jim and Bernie. I'm pretty much a beginner when it comes to turning. There's a lot I need to learn.

[Hummm, seems like the first thing I need to learn is the proper name of this chuck - it's Longworth and not Longwood as I originally put on my post. Sorry.]

Mike

[Ben Gastfriend]

Wow! I really like the look of that and with the prices of chucks, I just might have to make myself a slightly smaller version. I'm a bit confused though why you changed from the original 4 jaws to 6? Just more gripping power?

Advice from someone who's already made one (ahhem) would be great. Thanks, and good job!

[Mike Henderson]

Wow! I really like the look of that and with the prices of chucks, I just might have to make myself a slightly smaller version. I'm a bit confused though why you changed from the original 4 jaws to 6? Just more gripping power?

Advice from someone who's already made one (ahhem) would be great. Thanks, and good job!
Ben - I just figured that the more fingers gripping the bowl, the better the bowl will be held. I thought about eight but decided to stay with six for a first attempt.

Mike

[Jim Becker]

Ben, this kind of chuck is just for final finishing of the bottom...not for "regular" soup to nuts turning. Learn to use glue-blocks as your "chuck" for awhile. And if you are not attending Bucks Woodturners, consider doing so. They meet the 3rd Monday of each month, 7:30p, in the woodworking shop at Bucks County Community College. (Some months go to the 4th Monday due to those "Monday legal holidays" that the school is closed) They club does not meet in July or August. And if you can't do that, when I'm finally through all the furniture and cabinetry for our addition, come up here for a few hours and I'll show you how to leverage alternative mounting techniques.