Have a Ball....

[David DeCristoforo]

Sphere #1


I'm calling this #1 because A) it's the first one I have been able to successfully complete and 2) I plan to make more. The question might arise, "Why?" And I would have to answer "I don't know". I just suddenly became struck with and urge to make spheres. Actually, I have wanted to make a spherical hollow form for some time but feared I lacked the skill. My first attempt was a dismal failure. It just kept getting smaller and smaller as I tried to get it perfectly round. The second one ended up as a bowl of sorts after the top blew apart. Most people make their funnels with a hole in the bottom, but not me!

I think part of my fascination is the difficulty of making a simple shape like this. It's almost impossible to "eyeball" the profile. It never looks perfect no matter how hard you squint. I kept checking this with a template and it seemed "pretty close" but still, I was not confident. So I took a picture of it on the lathe, dropped it into an Adobe Illustrator file and superimposed a circle over it. It was not "perfect" but it was sooooo close! And in truth, even the slightest wood movement will throw it off a bit. This is 6" in diameter, hollowed to a wall thickness of a "fat" 1/8" through a 1" opening. I left a little extra at the bottom to weight it slightly so it would not just roll over.

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[Paul Williams]

Great job David. What kind of wood is that? The color looks like osage orange, but I am not sure the grain does.

[Scott Hackler]

That "turned" out pretty good. I am currently fighting the sphere obsession with some Christmas bulbs and it's frustrating...I know. I have almost convinced myself to build a sphere jig!

[Alan Trout]

Cool piece of wood. That is a shape that has been on my to do list for a long time.

Alan

[Deane Allinson]

I am glad that it is #1; of 30-40?. I wait to see your variations on this theme.
Deane

[Roger Chandler]

Nice work David! The coloration does look a bit like osage orange, but the grain ..........the end grain of OO does resemble this, so give us the low down.........what wood did you use for this sphere?

I think hollowing a sphere would likely be a bit harder than the elongated forms traditionally seen in hollow forms.

[David DeCristoforo]

"... I wait to see your variations ..."

Well that might be the hard part. I cannot imagine too many variations other than the size, material and/or color. A sphere is a sphere. That is one of the things about that is interesting. It's a "target", a known value. You know from the start what you want to end up with. So it comes down to getting as close as possible with no "latitude" in form.

The wood is from a Chinese pistachio tree that came down in a storm last year. This is the third piece I have made from the bit of it I was able to talk the firewood guys out of. I have a few chunks left...

[Alan Trout]

The grain pattern suits the form very well. Gives it tons of motion.

Alan

[John Keeton]

Well done, David!! Every since Jack Mincey did his sphere form, I have been intrigued by them. I love the wood, and I bet a sphere from Claro walnut would be neat! Or, the sissoo that Kathy Marshall turns.... Or, the ....

Well, anyway, I think that is where the variations come in. How about doing one from maple and airbrushing a globe on to it with dyes??

[Curt Fuller]

That's beautiful. What seems like such a simple form is probably the most difficult and least forgiving. It's either round or it isn't. The small opening and the angle that you photographed it at really make it look cool.

[David E Keller]

Too cool! This is another project on my bucket list... I tried once with a piece of bone dry sycamore, and I rapidly decided to quit... The piece I had was hard as concrete. I'll probably just drill two more holes in it and leave it at the local bowling alley. These would be fun in madrone burl!

[Donny Lawson]

I want to make snowmen ornaments for presents using the sphere method but my spheres turn out more oval than anything else. I guess it just takes practice and more practice. I love your sphere and the wood. Now make 2 more smaller than the first and make a nice snowman that is hollow. Thats a good challange

[David DeCristoforo]

"...I bet a sphere from Claro walnut...Or, the sissoo that Kathy Marshall turns.... Or, the ...."
"...These would be fun in madrone burl!..."

Aha! See? That's where it goes!

"How about doing one from maple and airbrushing a globe on to it with dyes??"

I think I will leave that one to you!

[Roland Martin]

Nice! That does look like a challenge, and one I'll wait a bit on. The wood really does a lot for this piece.

[Baxter Smith]

Nice work David! The grain and the angle make for a neat picture. I have tried one once. The best I could do was to make it kind of round. Just curious, but is this one dry enough to stay round?

[Bernie Weishapl]

Really nice David. Really like the grain in that wood.

[Ken Fitzgerald]

Very nice DoubleD. That wood is interesting.

[Rick Markham]

It's awesome David! I'm glad this one cooperated! It's cool, I'm gonna have to try one of those slowly disappearing into nothing variations you spoke of :D

[Bill Bolen]

Congrat's David! Sphere's are tough. Just ask me, I've failed more times than I would care to own up to!

[David Reed]

Way cool David. There is a lot going on with this lovely piece of wood with the great grain patterns.
Spheres are tough indeed but I just finished one (smaller - about 4") using a trick I learned online. Spin it on one axis and cut a groove with a parting tool, rotate it 90 degrees and cut it using the circular groove as a guide. Give it a try - it helps a lot. The one I just turned last week is BLM burl.

[Reed Gray]

David is off on another tangent. Sorry, couldn't resist.

Turning a sphere on a single axis is difficult. Using cup chucks, and turning on 3 different axisssss (or how ever you spell and say it) is simple. Two axis through the pole and one through the equator. Rough form, put between cup chucks (softer wood than your sphere). Turn smooth. Draw a pencil line in about the center with the rotation of the spinning wood. Rotate 90 degrees so the pencil line runs through the cup chuck. Very gently turn down to the line, but not through it. Draw another line at 90 degrees to the first one. Rotate again so the poles are in the cup chucks. Go through the rotation a couple of times and you have a sphere.

robo hippy

[Joe Watson]

That looks pretty cool.

[David DeCristoforo]

"David is off on another tangent..."

Could be.... The suggestions about using either a groove (D.R.) or pencil lines (R.G.) as guides are interesting. But that brings up a question in my simple mind. Once you form a sphere using these techniques, how do you hold it securely enough to hollow it out? This one is 6" in diameter and I would like to make larger ones. Either of the suggested methods would preclude the use of a chuck which is how I did this one. I guess maybe one of those "donut chuck" things?

"...is this one dry enough to stay round?"

Don't know. Probably not but I've made a couple of things from this wood and it seems to be pretty stable so maybe it will be OK. So far it's still round...

[Josh Bowman]

I like it!

[David Reed]

Here is a link to the directions for the way I did mine.
http://www.woodturners.org/tech_tips/round-balls-instructions.pdf
I did not hollow as that would actually interfere with it's intended function but after hollowing while still chucked, you could reverse chuck it using the hollowing opening for the jaws or just make a cup chuck and lots of tape to clean off the spigot.
I looked at the three axis turning and found no benefit over using two axes. It helped to apply black marker to the groove to help make it more visible. I also think making it a bit wider would help visualizing the 'inner sphere'.

[Scott Hackler]

Turning a sphere on a single axis is difficult. Using cup chucks, and turning on 3 different axisssss (or how ever you spell and say it) is simple. Two axis through the pole and one through the equator. Rough form, put between cup chucks (softer wood than your sphere). Turn smooth. Draw a pencil line in about the center with the rotation of the spinning wood. Rotate 90 degrees so the pencil line runs through the cup chuck. Very gently turn down to the line, but not through it. Draw another line at 90 degrees to the first one. Rotate again so the poles are in the cup chucks. Go through the rotation a couple of times and you have a sphere.

robo hippy

Reed, that is GOOD info. I was talking to one of our senior club members about some spheres he turned and he meantioned turning them between cups. But my attempt didn't work as well. Using a line as a guide makes a lot of sense. I will definitely be trying this method and trying to rig up a holding jig to hollow them out. Thanks Obi-Wan!

David, thanks for the PDF as well. That opens up a few ideas too.

[David DeCristoforo]

I'll be interested in hearing how this works out for you. I'm leaning towards the "groove" idea, mostly because I want a tenon for chucking. I'm not at all comfortable with the idea of trying to hollow a 6" - 8" sphere held between "cups"! In fact, I cannot even visualize it.

[Dick Wilson]

I may have missed it in you post but what kind of wood is it? Marvelous grain pattern. It looks like the wood as already moved a bit. Rather that taking the time and expense of making a ball jig I cut an inch off the end of a PVC pipe. Lay it on the turning and turn until there is no light under the PVC. I have several different diameter PVC rings for different size balls. It ain't perfect but it looks round to the human eye.

[Dale Miner]

Once you form a sphere using these techniques, how do you hold it securely enough to hollow it out? This one is 6" in diameter and I would like to make larger ones.

David,

I've turned a few hollow spheres. Start out as a hollow form, rough green endgrain to a fat in the middle sphere to allow for drying shrinkage. Leave the chucking tenon on the bottom. Once dry, jam chuck the opening on a stub, using the center point mark in the tenon to center on the live center. Recut the tenon and shoulder true. Chuck on the tenon, cut the outside using a template to get as close as possible. The pvc or gatoraide lid thing helps. Rehollow the inside to whatever wall thinness you are after/comfortable with. Reverse back onto a stub, and cut as much of the tenon away as possible. Put in the jam cups, and do the multi axis shadow line thing. I still have one here that was done a couple of years ago. I will see if I can find a picture and post it.

Dale

[Brian Weaver]

Hi David, here's how I held the balls that I just posted pics of when I did my hollowing.

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[David DeCristoforo]

Brian and Dale.... I could not possibly bring myself to use such a "loosy goosy" method. My own method is so much more refined and accurate. I had thought to keep it secret, maybe to be revealed upon my demise but maybe to be kept locked away forever, taken to the grave, leaving the rest of you to try and puzzle it out for yourselves. But my conscience has gotten the better of me so in the spirit of camaraderie and open sharing that seems to permeate the "turning world" I have decided to reveal it here. It's pure genius, I know. But what can I say? Some of us are blessed....

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[Reed Gray]

You can turn the sphere between cups, but not hollow it that way. I would think the doughnut chuck would work. Might want a cup on the headstock end and maybe some carpet tape in the chuck.

I really like the off center/weight to one side idea. Might have to try that one.

robo hippy

[Dale Miner]

First off, Brian, thanks for the pics. The size of the balls is amazing in itself. One of these days...... Round tuit thing.....
Thanks again.

David, thanks for the expose. Woodturners can't help but be a caring and sharing bunch. Can I borrow your gauge sometime?

[David DeCristoforo]

" Can I borrow your gauge sometime?"

Well I suppose that once something like this is posted on a public forum, it's pretty much "fair game". But I have to caution you, it takes an extraordinary level of skill with scissors to make one of these.

[Dan Hintz]

But I have to caution you, it takes an extraordinary level of skill with scissors to make one of these.
So that's how you make yours so clean... I've been tearing them by hand!

[David DeCristoforo]

"... I've been tearing them by hand..."

That's how I was doing them too. But then one day my daughter saw me doing it and taught me about scissors. I've never looked back...

[David E Keller]

I have a tendency to run with scissors... Always have. Is there someplace online that sells high end sphere gauges like the one DD has so craftily created?

[David Reed]

I have access to an entire workshop of 'sphere guage pruducers' at my hospital. Depending on the bite radius of the patient, aka dog, we can turn out quite a variety of sizes. Some of the larger sizes require a bit of lead time as I don't always have a croc handy.

[Kevin Lucas]

One of the older men at our club meetings does a lot of spheres. He is a retired machinist who made an arm that mounts to the bed right at center with a straight tip. Swivel left and right to make the sphere. I think his neatest idea is a piece of pvc with threads on each end a cap screws on to. One cap goes in your jaws the other is for holding the ball and you can hollow the ball like a hollow form.

[David DeCristoforo]

I would love to see some pics of these rigs. I have seen the swinging arm setups but the holding system sounds intriguing...

[Nate Davey]

I would like to see those pics too.

[george wilson]

Ever take one of those quizzes on a computer where you are supposed to choose where the center of a circle is,or which parallelogram has parallel sides,etc.? The computer slightly distorts these geometric images,so I wouldn't rely on it to tell you if your ball is round. Just make a template and check it in person. There is something you have to do to the computer to make it show those things correctly. I don't know what.

[David DeCristoforo]

Hey George. I appreciate the perspective on perspective. I figured my computer display would be "pretty close". Probably not as accurate as my precision measuring device. But close enough….

[Dale Miner]

I'll be interested in hearing how this works out for you. I'm leaning towards the "groove" idea, mostly because I want a tenon for chucking. I'm not at all comfortable with the idea of trying to hollow a 6" - 8" sphere held between "cups"! In fact, I cannot even visualize it.

David, for larger spheres, use larger cups. I've done 8"+ spheres with cups about 3" diameter.

[David DeCristoforo]

OK. I'm gonna show how dense I can be. I totally get the donut chuck thing and the cutting a groove thing and even the turning between several centers thing. But the hollowing "between cups" bit is not sinking in. It seems to me that to mount the sphere between cups, one cup has got to be right where you are going to want to stick your tool, so to speak. So what am I missing?

[Kevin Lucas]

No pics but I tried to do a drawing of the holder. It's crude but may give the right idea.215381

You get a section of pipe the size you want the ball to fit or turn the ball to fit it? One end cap you leave the lip on the back so you can use the chuck jaws and the front one you cut it off or turn it off so the front cap has a hole even with the top. The bonus with using the caps is that there are already round holes that the ball will set against. When the ball is put in and the front cap tightened its nice and secure. A good idea may be padding in the back. The front cap with the hole even with the top allows a little of the ball to stick out so you can tell the curve of the form. I see it as sort of a mini donut chuck and pvc comes in all kinds of sizes. It will probably work great for other things besides spheres. Hope I explained it ok )

[Steve Drummond]

Here is one of my early efforts on the path to making Chinese balls. It is huon pine with the twelve primary points pierced. Dodecahedrons - 12 sided geometric shapes are also interesting and a logical development from a sphere.215412

[Nate Davey]

David, try this link, the tutorial tab has a YouTube link.
http://www.lindsaylathetools.com/sphere/ (http://www.lindsaylathetools.com/sphere/) or
http://woodturninglearn.net/articles/bocceball.htm

[David DeCristoforo]

Thanx for the links, Nate and S.D and K.L for the pics. I'm suddenly realizing that this is one of those "more ways to skin a cat" things.... more than I will probably ever know. I'm looking forward to trying out some of these ideas...