Lidded oval thingy

[powderpost]

After the lidded box was finished, a 'friend' made a challenge..... "Do a laminated oval vase with a lid, can't can you?" Well the challenge was made. Round laminates were simple enough, but ovals, with multiple centres?
After a few attempts to keep the joints 'radial' and cope with the different shape and size of the segments, the pattern started to emerge. It was originally meant to be 175mm deep, but because of the amount of movement that started after 100mm a decision was made....... that is big enough. The box is now 125mm high over all, 90mm major axis and 75mm minor axis. It was made using a shop made chuck, made from wood.
First photo is of the finished article.
Second photo thingy opened.
Third photo is the chuck. The jam chuck for the lid is still there.
Jim

[coffenup]

Another fantastic job Jim
keep them coming to inspire all the rest of us
regards michael:2tsup::2tsup::2tsup:

[powderpost]

Thanks Michael...
Jim

[DJ’s Timber]

Nice one Jim, got any more details or pictures on your chuck there.

[powderpost]

DJ, I will take some more photos tomorrow, and post them tomorrow night.
Jim

[powderpost]

DJ, details of the oval turning chuck.
Pic 1 Complete chuck
Pic 2 Cover removed.
Pic 3 Face plate removed. Here you can see the slide, which is fixed to the lathe spindle, fitted between the slides. These are made from cooktown ironwood and heavily impregnated with a lanolin based oil. The centre plate is rotated by the lathe and causes the outer slides to oscillate, creating the oval shape.
Pic 5 Back of the slide mechanism. The two aluminium 'bearers' run on the large bearing seen in pic 4.
Pic 4 The bearing. The three bolts on the ply piece to which the bearing is attached, controls the difference between the major axis and the minor axis which controls the shape of the object.
The chuck has now done five jobs and is still holding up well. Most important not to operate it too fast, about 450 rpm seems to be good. This one by the way, is model 3. Each model has been improved on the previous model. There is mark 4 on the drawing board.
Jim

[DJ’s Timber]

Thanks for that Jim, can see how it works. You don't need any lube on the aluminium bearers and the bearing?

[powderpost]

The movement between the aluminium and the bearing is minimal, only a distance equal to the difference between the major and the minor axis. The bearing is another story, it is a sealed bearing but I guess it won't last forever.
Jim

[OGYT]

Jim, this is awesome! To cut and glue a segmented vase is mind boggling to me;:doh: but to turn an oval vase on a homemade ovalling mechanism is AWESOME!!:2tsup::2tsup:
Is that plywood backing board fastened permanently to this lathe?:?
What is the shaft that is sticking out of the bearing?:?
I don't understand how this thing works yet. I guess I'm too dense for it?:?

[powderpost]

Al, the ply backing is fixed to the lathe headstock but is removable. The rod you referred to, goes through the headstock shaft and provides the driving power for the chuck. The system is not my idea, but my interpretation of an oval turning chuck. These have been around for about two hundred years.
Jim

[Skew ChiDAMN!!]

I'm glad DJ asked. :2tsup:

Very interesting, Jim. I've occasionally thought about making my own but have only seen commercial (read: expen$ive) ones and have been told wood wouldn't handle the stresses.

So I was waiting until I finished my Rose Engine. (Another... oh... 10 years, give or take 5. :B)

Now I know better...

[powderpost]

Skew, I have one of the commercial chucks, made in N.S.W. and found it to be a bit heavy. It did cause some uncomfortable vibration on my heavy lathe (Woodfast mc908) where as my version, much lighter, causes less vibration at a higher speed, and on a smaller, lighter lathe. The first chucks I built did wear quickly (after three jobs), but on the latest model I have used lanolin oil liberally on the ironwood runners. The next one will have nylon or brass runners, although I think the oil soaked wood might prove to be just as good.
Jim

[Skew ChiDAMN!!]

I wonder how a thin veneer of Lignum Vitae would go on the runners? I've a few pieces that are too thin for anything else, although I'm reluctant to throw them in the firewood pile.

Then again, maybe I should just use scraps for my first... I'm bound to want to "improve" on my first miserable attempt. :roll:

[OGYT]

Jim, thanks for answering my questions. I don't think I have the know-how to try to build something like this. I think you deserve a bunch of greenies for this one. Very High on the "Quite an Accomplishment" list!
Greenie Launched.

[powderpost]

Thanks Al.
Jim