Segmented bowl question?

Longworth Chuck

Dominic Greco in Richboro PA

>Alan,

Look for the plans for a Longworth Chuck. I believe that they are on the Woodturner pro site (or that you can buy a complete one there). I've seen this used to "center" a segmented ring on a bowl while on the lathe.

If you have a copy of Woodturner Pro, there is a free plan for that program that shows how to make a jig that utilizes the Longworth Chuck to hold a bowl for glue up.

See ya,

Dominic

After I filled your trunk!

Mike Schwing from Md.

>After I filled your trunk with ash, apple, and cherry yesterday you're working on segmented stuff?

Geez! (just kidding)

Re: Segmented bowl question?

Russ Fairfield

>Iprefer to glue the entire piece together before turning so I can see the entire piece at one time while turning the outside. I know that some people glue and turn one ring at a time, but I have never been able to get the form right by doing that.

I also prefer to do all of the gluing on a flat surface so I always have gravity working with rather than against me.

I have several photos that will show the sequence. I don't know how to put all of them in a single message, so I will spread it out over several messages.

The first one shows the start of the stack. I spot glue the bottom ring to the melamine coated board on top of the work platform. It will stay in place, but can be removed with a sharp blow when the assembly is finished.

The layer is centered to the center pole and temporarily clamped in place.

Re: Answer - Part 2

Russ Fairfield

>Then I sopt glue three locating blocks around the perimeter of the loose ring. The blocks are scrap, and the glue is Medium-CA. A drop of glue on one piece and a spritz of accelerator on the other makes an quick bond.

Re: Answer, Part 3

Russ Fairfield

>Then I remove the temporary clamps, apply the glue, and reclamp using the blocks to locate the ring and keep it from swinning away.

Re: Answer, Part 4

Russ Fairfield

>Then I repeat one layer at a time until the assembly is complete.

This one is 15" diameter and I am working on a 16" work platform.

There are other ways to to do this, but this one works for me. The advantage of using multiple clamps is that I can see the glue squeeze and be able to add another clamp if there is a trouble spot.

Re: After I filled your trunk!

Alan Tolchinsky

>Hey Mike, I'm finished with all the stuff you gave me. Only kidding. :) I just like to keep busy and stay out of trouble. That means I have to multitask and do both kinds of bowls at teh same time. Alan in Md.

Russ, thanks so much for that

Alan Tolchinsky

>great tutorial. That makes a lot of sense to me and I'll try it on my next one. I like the way you center the rings and keep it centered with the little temporary "tabs" you CA glued on. Now the rings shouldn't slide around so much when glued. I sure do appreciate having you on this board. If you ever quit, I'll have to go move near you. :) Alan

Re: Longworth Chuck

Alan Tolchinsky

>Thanks Dominic, I'll check that out. But what happened to " See ya around"? Alan in Md.

Re: Segmented bowl question?

Joel Hunnicutt

>I, like Russ, prefer to glue them all at one time. I measure the midpoint of the segments and draw a line at a right angle to that point on 4 sides. Then when I stack on the next ring, I match the glue joints with those lines. That assures me that all the rings are centered on each other (and that all my gluejoints match up)

Re: Segmented bowl question?

Keith Tompkins

>Hi Alan, I take a different approach than most...I glue up my rings just a couple of pieces at a time, and clamp and let them dry. When I have two half-circles, I run them through my jointer on a sled to get a perfectly straingt edge, then glue the two halves together. I may work on several rings at once, so it isn't as time consuming as it may appear. (sometimes several different projects)

I true up the faces of the rings one at a time, and continue to glue each trued ring to the previously trued ring.

It takes a bit longer, but the results are worth the extra effort. Every glue joint is perfect.

Re: Segmented bowl question? *LINK*

George Troy

>I use a self centering cone which I got from Curt Theobald (cwtheobald@wyoming.com) The cone screws on to a Oneway Live center. Segments centers are marked and position. The cone squeezes out the excess glue and gets it ready to put in my press. There is no slide or rings off line. Like Theobald I now work within .001 accuracy for rings and alignment. I turn each ring when it go backs on the lathe to a designed .750 or what ever is called for from your pattern. I may also use my drum sander to knock down rings in advance. All you need is one side flat. It is easier to work from the inside out to get that curve in the bottom. All the other methods given here work and I have used them all at one time. GT




http://groups.msn.com/CreativeWoodturnersII

Jointer Sled

Bob Matern

>Keith:

Could you try to describe the jointer sled and how you use it, especially since you would be trying to joint end grain. Thanks

Re: Excellent Thread ThanX

Steve Mushinski

>This has been an outstanding thread.

I thank all those in the know, for the detailed description with pictures.

Great work!

Re: Jointer Sled

Keith Tompkins

>If it's end grain, make a table saw sled instead. Plywood or mdf work ok. using your mitre-slot as a guide, run the sled through the blade. Now secure your half-ring to overhang the saw cut slightly, and make a pass through the blade.

Re: Segmented bowl question? *LINK*

Dave Shombert

>Alan - I glue all the rings together before I turn anything. That is to say, I glue the first ring to the second, let it dry, then glue those two to the third, let THAT dry, etc. When they're all glued together, then the whole mess goes on the lathe.

There's a couple things you can do to keep them from moving around while the glue is wet. One is to make sure the clamping pressure is perfectly perpendicular to the surface. I used to clamp them in a cheap Delta drill press, and had lots of problems because the quill was not not orthogonal to the table. Then I had some good ring presses made and that helped a lot. Also, let the glue tack a little bit before you put the rings together. Once they're together, apply slight pressure and motion, as if you want to spread the glue around in the joint, until you feel it start to grab. THen - pretty quickly - check your positioning against whatever reference marks you're using. Then apply slight pressure with the press, wait a couple minutes, then apply full pressure.

Hope this helps. THere are some photos of the process on my website.

Dave Shombert

Elkins, WV


http://www.woodspunworkshop.com

Re: Jointer Sled

Alan Tolchinsky

>I just use a large sheet of sandpaper stuck to something very flat like a cast iron TS wing or a piece of melamine. Then I take the half circles and sand the ends until they are perfectly flush. If your angle is pretty close it doesn't take much sanding. Alan in Md.

Thanks again to all for the very

Alan Tolchinsky

>ingenious ideas here. It shows you there's more than one way to skin a cat. Alan in Md.

Re: Segmented bowl question?

Russ Fairfield

>For me, turning the outside of the form in one-piece has become more important as the forms have become larger. An unbalance in shape or minor errors in curvature that were invisible in a small piece became magnified and more obvious as the forms grew in size. However, turning "whole" is limited by the size of our lathe. When we cannot turn the entire piece, careful planning and accuracy become more important.

There are a lot of different ways to cut, assemble, and turn segmented work; and we often stand around arguing that our way is the best way. The truth is that there is no right or wrong way to do anything, there are just different ways. Which one we use will depend on a lot of things - form, size, design, how we think. The tools and machines that we have or are willing to purchase will also determine how we do things. Just because I use a Miter Saw doesn't mean that anyone should run out and purchase one of them if they already have a perfectly good table saw or bandsaw in their shop. It just means that we will have to do things differently.

Everything I make is simple in both form and design, and larger than what most folks are doing. The smallest segment piece I have ever made is an 11" bowl, and the 24" lathe is now a restriction on what I would like to be making. How I cut and assemble the pieces is influenced by my ability to make a good joint in these large diameter rings as quickly as possible(Emphasis on the "my ability"). I have used the single screw clamping devices, lathe mounted accessories, and a drill press very effectively on smaller shapes; but I have never been able to make them work very well for large sermented rings. Again, that may be a personal problem.

Fantastic info at this link... *LINK*

mbatarga

>I don't think anyone has mentioned this site. I found it some time ago while browsing the web. I don't know if this turner posts here or not. Great gallery for ideas, as well as sharing of techniques and jigs.


http://www.turnedwood.com/index.shtml