Best way to make a wooden ball ?

[Dog]

I want to make a hollow wooden ball 18" in diameter, how can I go about doing this and which wood to use ?

 

[DaveL]

Richard,

I have no idea how to do this, but a little more info would help

Is it going outside?

You say hollow, do you need/want it to come apart?
How thick do you want the wall to be?
What sort of finnish are you looking for? Show off the grain of the timber down to paint :shock:

See your not the only one to ask questions 8)

 

[Dog]

I thought I'd ask a 'special question' for a change :wink:

Inside use. 1/2- 3/4" thick wall. Will be stained and polished. Oops, to come apart, in half. (two halfs that fit together)

*edited because of excessive beer consumption yesterday* :roll:

 

[DaveL]

OK then Richard,

In The Router No57 Geoff Lucas made a jig to use a router (sic) to cut a sphere. He used a lathe to hold and rotate the work. Of course he was not making 18" dia balls they only look like 4" or 6".

I think the idea could be adapted and expanded to cut the outside of your ball. 8)

Its the hollowing out that I am currently have problems with. I need to think about this for a bit.

 

[Dog]

Yes Dave you are right, indeed a jig is available as I have the plans to build one which will cope with a sphere upto 2' but I'm stuck on the hollowing bit too :roll:

 

[Steve Maskery]

I can feel another router jig coming on.
Have you got one of those little Bosch ones where the body comes out of the frame? You could mount this horizontally on the lathe bed so that it swivels 8 1/2" from the tool tip.
Part turn the hemisphere, hold it by the North Pole, and slowly advance the jig, swinging it as you go. It will gradually eat into the workpiece hollowing it out. When the pivot point reaches flush with the Equator, you are done.
This is all conjecture, I have no idea if it would work in practice!

Cheers
Steve

 

[Dog]

Hi Steve, as it happens I do have one of those routers and a lathe so I may well give your suggestion a try and any other suggestions for that matter

 

[DaveL]

Steve,

That does sound as though it would work and bizarrely I have a Bosch 500 router, don't about Richard. If you want one, pop along to Homebase they have been selling them for £25 which I think is quite a good deal. My one some years ago was best part of £80.

 

[DaveL]

Well Richard, you posted while I was typing. You have all the bits to make lots of dust! :lol:

 

[Dog]

There's just one slight problem here, we haven't discussed how to make the ball to begin with :lol:

 

[Dog]

Yes Dave you are right, indeed a jig is available as I have the plans to build one which will cope with a sphere upto 2' but I'm stuck on the hollowing bit too :roll:

To quote myself, this jig only 'surfaces' a ready made sphere :wink:

 

[Aragorn]

At the risk of simplifying probably a tricky problem, can't the two halves of the ball just be turn in the usual way on the lathe, very accurately and then just joined together???
Or have I missed the point here :roll:

 

[Dog]

Quite possibly but I realise now that the lathe I have can not cope with turning a sphere of this size. I'll just have to find another way of doing this but thanks for all your suggestions anyway

 

[DaveL]

At the risk of simplifying probably a tricky problem, can't the two halves of the ball just be turn in the usual way on the lathe, very accurately and then just joined together???
Or have I missed the point here :roll:

Well I am not a turner but thought that turning a true sphere was on the hard side, maybe one of the turners would like to comment?

The jig that I have seen in The Router is used to cut an accurate sphere, after roughing the shape on the lathe. This is done to speed things up as the router is a slow way of doing the job but has better control than turning.

But I agree that as Richard wants it to come apart making it as 2 halves is the way to go.

 

[Anonymous]

Richard

How about cutting 'C' shaped 'ribs' of diminishing size on the bandsaw and glueing these together like laminates to form the rough shape of your hollow sphere?

You can tidy it up with small grinder/sander/chisels/sandpaper etc.

Works in principle for me

Cheers

Tony

 

[Aragorn]

Dog
(nearly typed God then! That's not you is it? :wink: )
What's the sphere for? Just curious - but it may suggest a method or alternative.

 

[Anonymous]

No I'm not God and 'Dog' has been retired as I felt like a change :wink:

The sphere is something that arrived in my head as a project. If I manage to create it, it will become a completely round 'chest/trunk/box' with a custom made hinge and clasp. My imagination sees this project as a pine sphere (preferably) stained and highly polished. I can see it clearly, it is just getting that image to become reallity which is the minor stumbling block at the moment

Richard