Whats the quickest way to turn small spheres ?

[JDarvall]

Make up a jig I guess off the lathe.

Been asked to make cedar balls. lots of them.....out of a cedar stump.

Been specifically instructed to make them perfectly sylindrical (however you spell that)

I forsee making a truck load of money out cedar baallls :rolleyes::D....so I'm after the most efficient cedar ballls fabrication method known to man.

Thanks.

[Woodlee]

Make up a jig I guess off the lathe.

Been asked to make cedar balls. lots of them.....out of a cedar stump.

Been specifically instructed to make them perfectly sylindrical (however you spell that)

I forsee making a truck load of money out cedar baallls :rolleyes::D....so I'm after the most efficient cedar ballls fabrication method known to man.

Thanks.

Make a ball turning jig similar to the ones made for turning steel balls.
Just google for ball turning tool .

I have to go out right now ,but I have some links to metal turning sites that have them.
Ill post some later.

Here you go

http://homepage3.nifty.com/amigos/radius_cutting_attachment/radius_cutting_tool-e.htm
http://www.metalwebnews.com/howto/turning-tool/spherical_turning_tool.pdf

Whilst these are made from steel you could probably make one up from hardwood .
At least these will give you the general princiapl and how spheres are achieved.

Kev.

[Jim Carroll]

Vermec sell a sphere jig.

You could also use old holesaws reground

[jmk89]

Make up a jig I guess off the lathe.

Been asked to make cedar balls. lots of them.....out of a cedar stump.

Been specifically instructed to make them perfectly sylindrical (however you spell that)

I forsee making a truck load of money out cedar baallls :rolleyes::D....so I'm after the most efficient cedar ballls fabrication method known to man.

Thanks.

Do you mean "cylindrical" or "spherical"? Spherical is a perfectly round ball, while cylindrical is like a round rod (think if dowel). If they asked for cylinders, that would be much easier:D

[ian]

Make up a jig I guess off the lathe.

Been asked to make cedar balls. lots of them.....out of a cedar stump.

Been specifically instructed to make them perfectly sylindrical (however you spell that) you mean spherical?


I forsee making a truck load of money out cedar baallls :rolleyes::D....so I'm after the most efficient cedar ballls fabrication method known to man.

Thanks.turning the spheres should be pretty straight forward, but the request for "perfectly spherical" makes me wonder a bit.
If a ball is a little off a perfect sphere it shouldn't matter UNLESS the balls have to roll or tumble truly, in which case each one may need to be individually balanced.

be sure to clarrify this before you quote a price


ian

[soundman]

Hmm, never tried it but I have seen several ways of doing it.
This perfectly spherical thing is a matter of concern...........what do they mean perfectly......... do they have any idea what perfectly spherical is.


you could make some sort of pivoting cutting tool thing.

I have heard of turning spheres with a tool made of pipe:?

cheers

[joe greiner]

G'day, Jake.

Google [woodturning ball jig] for a tonne and a half of possibilities.

By all means, establish the tolerances for the product before submitting a quote. Even with "perfect" quality control, climate will change the dimensions; 'tis the nature of the beast. If the tolerances are incompatible, run away.

Joe

[Pusser]

The method using a belt sander described here http://www.woodworkforums.ubeaut.com.au/showthread.php?t=61455 was originally designed for making 1" balls but it works for most sizes providing the gaps are kept small enough to stop the balls escaping.

[ian]

I have heard of turning spheres with a tool made of pipe:?the pipe is round and hollow — a sphere is round in section
jam the pipe at right angles into a cylinder of wood
when it stops cutting you will ahve a sphere inside the pipe


ian

[mobjack68]

the pipe is round and hollow — a sphere is round in section
jam the pipe at right angles into a cylinder of wood
when it stops cutting you will ahve a sphere inside the pipe


ian

I am thinking, move away from the lathe idea for spheres.....They make a drill press tool for making rosettes. (square blocks that sit at the corner of old house door frames,, eliminated the 45 mitre cut for door trim) I would think that if you could come up with something like a "drill bit" that would cut a hemisphere in half the thickness of a block of wood, turn the block over and cut the other half, freeing the sphere??? or like a "pencil sharpener" you know the little plastic ones where you insert the pencil and turn?? adapt this idea to turn half of a block, turn the block over and cut the rest....Look for some internet info for "tumbling" finishing. The spheres would be placed in a tumbler or vibrating finishing tub with whatever media would remove the "flash" (the little bit left over when the two cuts meet) to finish the little balls with a minimum of hand work...I can picture all of this in my head...if you want me to scan my head so you can see what I am talking about, let me know...

[Skew ChiDAMN!!]

the pipe is round and hollow — a sphere is round in section
jam the pipe at right angles into a cylinder of wood
when it stops cutting you will ahve a sphere inside the pipe

That's how I do it and it's relatively quick. A word of caution, though: the diameter of the blank (and the finished sphere) should be significantly larger than the inside diameter of the pipe. If it's turned down to the same size, so the sphere can slip into the pipe then all sorts of nasty things can happen due to jamming. DAMHIKT. :no:

I also don't "just jam the pipe in at right angles"... I move it in an arc from side to side on the tool rest, so the LH edge of the pipe reaches to the tenon and the RH edge passes the turning axis of the ball. This results in a smoother finish and also makes it closer to "perfectly" spherical. (Nothing is perfect. :wink:)

The traditional method is to turn the blank cylindrical, cut it's length to just over the diameter, remount between centres at 90° and turn down to the shadow line. For better accuracy, it's usually rotated 90° one more time for finishing. This is accurate, but slow and takes some skill.

For a lot of small balls, such as rosary beads, I suspect that the upside down belt-sander would be much, much more efficient. I haven't tried it for myself, but I've done similar with lapidary work and, once you've timed the first batch, you can walk away for the allotted time for subsequent batches. ie. it doesn't need as much labour. Not that it's a good idea to walk away leaving any machine unattended, of course, but the point is that you can.

[scooter]

Not that it's a good idea to walk away leaving any machine unattended, of course, but the point is that you can.

Esp. a linisher like mine that mistracks if you look at it askance... :roll:

[JDarvall]

Thanks for the ideas.

No, they don't have to be perfectly round. Sorry, I mislead there. As long as they don't look like eggs.

Sounds like that belt sanders a good idea. So you can end up with a close to finished result straight from the sander with little hand work ? Tumble each ball over a few different grades....

The lathe does sound like too slow an approach for the job eh.

[Alastair]

If you are a purist, you should turn them by eye, and check them with a template!!!

However, wotskewsed is the way to go.

regards

[OGYT]

Apricotripper, some good advice herein. The sharpened pipe will work, as will a half-circle template. I attended a class on turning spheres while I was at SWAT Symposium in October.
Here's the fastest way for me to do it:
Turn a ball approximately round... pretty near round, close as you can get it done quickly, and part it off the lathe.:?
Turn a jam chuck out of softer wood, with an opening that is just slightly smaller than the largest diameter of the ball, but make sure it is deeper than the ball diameter. (you just want the ball to be held by the outer edge of the jam chuck, and not make contact anywhere else) Dampen the inside edge of the jam chuck with water. Jam (light tap) the ball into the chuck. :D It'll hold, and over half the ball will be where you can get to it.
Now turn one groove around the largest diameter of the ball with a parting tool. Turn the groove just deep enough to go completely around, without any gaps. (this is perfectly round) Shade the groove with pencil. Remove the ball from the jam chuck, and re-insert it (rotated 90 degrees) with the groove centered in the jam chuck, in line with the bed ways.
Now turn down the outer (tailstock) side of the ball just 'til there is just a very slight pencil mark left where the groove was. It will be as close to perfect as it can be done on a lathe. Sand away the pencil mark and finish that part of the ball you just turned round.
Turn the ball around with the other part of the pencil-marked groove to the outside, and finish turn away the groove. Sand and finish it. Done.
It is a lot easier than it sounds. Once you have one, the same jam chuck can be used for all 3" spheres. I can turn a 3" sphere in about 20 minutes. Quicker after I get at it a while.:2tsup:

[Hickory]

I have made a few, used a skew to shape all but the final parting.

I also made a piece chucked up and turned a matching cove, fit the ball into the half circle cove and let it spin in my hand. held some sandpaper and allowed nature to take its course and shape out the rest till it rolled around freely in the cove.

[rightuppercut]

I made a jig with a small laminating router. You route half the sphere and then reverse it using a vacuum chuck. The jig is not hard to make, but I'm looking into somehow making it from metal so it stays nice and stable.

[JDarvall]

Thanks for the ideas.

I'm not sure what you mean by Jam chuck Al. Thats where I lost you. I'm not a turner. Quite wet behind the ears at turning. Just self taught I am.

Most attracted to that jig of yours rightuppercut. But can't do that cause I don't have a vaccum chuck.

[OGYT]

The "jam" chuck is a piece of soft wood, with a depression turned in it that is deeper than 1/2 the diameter of the sphere, but the diameter of the depression is less than the diameter of the sphere. That way, the sphere will not go all the way into the chuck when you jam it in there.
Actually, when you jam the sphere into the "jam" chuck, it will not touch bottom, and it will leave more than 1/2 of the sphere sticking outside, so you can work over half of it at one time. Dampening the inside edge of the jam chuck will make the ball of wood stick to it, sorta, so you can turn the sphere.

[JDarvall]

Gotcha. Thanks Al.

Amazes me that the ball will hold enough that way. Give it a few taps with a mallet I suppose.

[joe greiner]

Gotcha. Thanks Al.

Amazes me that the ball will hold enough that way. Give it a few taps with a mallet I suppose.

Amazes me, too. I put a soft pressure pad on the tailstock live centre, and use a shallower cup on the headstock for access to more of the surface for final sanding. BTW, what size spheres are you after?

Joe

[JDarvall]

Amazes me, too. I put a soft pressure pad on the tailstock live centre, and use a shallower cup on the headstock for access to more of the surface for final sanding. BTW, what size spheres are you after?

Joe something like 3/4" diameter I guess....Like big marbles I suppose....cedar balls....uno, there just those balls you put around your house in draws and that sort of things to keep the bugs out. Think they make them out of Camphour as well.

Seems to be so many ways to do things like this. I've got a bit of experimenting to do . :wink:

[OGYT]

Gotcha. Thanks Al.

Amazes me that the ball will hold enough that way. Give it a few taps with a mallet I suppose.

Actually, I just bump it slightly with the heel of my hand.:2tsup: It doesn't take much. I've had 'em stick so tight I had to remove it chuck and all, and knock it against the workbench to break it loose. :(( In fact, it might be a good idea to drill a through hole so you can use the knockout rod to get the ball out in case it's really stuck...:2tsup:

I just read your post right above this one. Didn't know you wanted such small spheres. I don't know if I'd ever try to make one that small. 2"/50mm would be the smallest I'd try to make. The larger the sphere, the easier my method works.