Can anybody help? Large turning required

[13eightyfour]

Its been a long time since ive posted here, Ive been incredibly busy with none wood related projects.

My current project though could be wood related im looking at the possibility of a turned jet like orb, but the dimensions are far to big for me to even attempt, it wont even fit on my lathe.

The pics below give a rough idea of the scale of the orb, Im unsure as to whether the orb can be achieved by turning, i need the wall thickness to be as small as possible 3-5mm ideally based on the dimensions shown. If i incresed the size of the 'orb' i could get away with 10-15mm for the wall thickness.

Is this even possible? Can anybody do it and be able to cut the 'orb in half like shown in the picture so the 2 halves can be attached almost seamlessly?

Im not really fussed about the wood choice whether its from a solid wood or even laminated ply?


Anybody got any ideas?

 

[Richard Findley]

That's pretty big :shock: :shock: we're talking 27" long by 18" diam. I reckon you need someone with a VB36 for that job!!! That's one heavy lump of wood!!! The only person I know with one of those and a timber stock of anything like that is George (Cornucopia) but I'm not sure if it's his kind of thing to be honest. Blister also has a VB but not sure if he has the wood or the hollowing skills? (No offence Blister, what I mean is I don't know if hollowing is your thing )

Best of luck

Richard

 

[Blister]

:shock:

Yes that is big

Would be a nightmare to attempt with the 3 to 5 mm wall thickness

But even more problems trying to hold and cut it seamlessly

Problems that come to mind are

choice of wood blank
The inclusion of any knots shakes
Distortion before cutting in half
Distortion when cut in half

I have hollowed a vase to 20' left the wall thickness at 1" it distorted when drying

Reduced the wall thickness to 1/2" and it distorted again
:?

I have left it for some 6 months now and will one day have another go but dont hold out much hope

 

[wizer]

Distortion is the big problem here. You're going to have to find a very skilled turner who is adept at hollowing. It will cost you an arm and a leg. How many do you want? It might be better to go with the 2 pieces option and get it CNC'd.

 

[duncanh]

Not sure you'll be able to get any dried timber this size to begin with, and even if you could it would cost a fortune.
This means you'll probably need a wet or part dried blank, which leaves you open to a lot of potential movement whilst it dries.

Depending on your intended use you might be able to turn the wood solid (from ply or mdf) create a mold and then make the final item from fibreglass. That should make it easier to build out of 2 halves and get the walls thin. Not that I know anything about fibreglass.

 

[13eightyfour]

Thanks for the replies, i did have a feeling that i was pushing what was possible.

Its for a friend of a friend whos setting up an artsy interiors shop, and has come to me for the business computer (bear with me here) the brief was it had to be seriously powerful but look nothing like a box and look beautiful and be silent. Its a concept which they hope to offer to people with far too much money

The internals arent a problem (the computer is the most powerful ive ever built), they all fit which is why the inner diameter is so important

The idea is the components are assembled in a 'skeleton' which then mounts to the bottom half, at the front will be a 220mm fan drawing air in and at the rear a 120mm used as an exhaust.

The final design does look amazing but its looking like fiberglass is the only way im going to achieve it.

For those interested heres what it should look like.

 

[wizer]

Interesting Idea. I was thinking speakers. Let us know how you get on with it.

 

[Blister]

Have a look here

http://www.hkdesigns.com/

Spun alloy :wink:

 

[Jonzjob]

Fibreglass would be the way to go there me-thinks? The most difficult part would be to make the mould, after that it's fairly straight forward.

I managed to make this a few years back and it's still going strong

There's 10 + sq meters of chopped strand mat and several gallons of resin in there, but apart from being time consuming to do as I said, straight forward.

And it now graces our piscine swimming pool..

 

[Harlequin]

I have done some large turnings for horns for loudspeakers
The largest thus far was about 450mm length and 400mm width.
They were done by routing out concentric rings from birch ply and building up the conical form.Precise routing helps when it comes to mounting on the lathe for final shaping (less wobble).
Will dig out some pics this evening if you are interested but CNC sounds the best way to me which allows a choice of materials as well