# Pictorial Guide to Turning a Sphere



## trc65 (Mar 4, 2021)

Turned a sphere this afternoon, and tried to take a picture at every point along the way. If you want to try this, I'd recommended watching or reading a few tutorials first to understand the process a little better. There are lots of different ways to do this, so I had a pretty good understanding of the process ahead of time. I'll dig out some references later tonight and post them. 

Some methods use lots of calculating (distances/diameters) and draw lots of guidelines during the process. I didn't want to do that, so after transferring the diameter to the length of the blank, I just winged it by eye. This may or not work for you, especially if you are just starting out. I got lucky, was able to get good spheres close to original size using this method, and got a lot better the more I made. The first few were almost 1/4" smaller than my starting diameter, but got better quickly as I made more and my eye got better seeing the shape.

Started out with a piece of black Locust that once rounded was 2 5/16" diameter. Didn't measure the length, but this one is a little tight as I will mount in jaws for the turning. I'd recommend using a blank 2"or so longer than the diameter to start. 

Turned it round and transferred the diameter to the blank, and added a center line.





You want to keep that center line if you can through the whole process. If you are really good, it will only be removed when you start sanding.

Side note: to my eye, the cylinder always looks longer than the diameter, and I struggled with that for the first few. Keep your dividers/calipers handy to check length, and redraw outside lines as necessary.

Used parting tool to cut down blank just to the outside of the lines. You can see I'm a little tight to the chuck.





Now for the first cuts. I started a little less than half way between the end line and cut a diagonal on both sides. What you ideally want after these first two cuts is an equal sided octagon. Mine probably isn't, but close enough.





Now, you want to make your octagon into a sixteen sided object, whatever that is called. You are just making more (hopefully equal) facets. Some methods have you draw more lines for each cut, I did it without.





At this point in time, most tutorials will have you cut more facets, I didn't, just cut by eye smoothing everything into what looked like a sphere to me. Remember to try to keep the center line, and re-measure/ re-mark your end lines as necessary. If you've cut the end lines too short, it will mean more work later on, and a smaller sphere.

This is what I ended up with after smoothing everything to a sphere-like form. It's not too bad here, but the left side looks to me to be a little off compared to the other. Rather than trying to correct it here, wait until it is parted off, and the axis is shifted. You will loose less diameter this way. If you start chasing shape now, you can loose a lot of diameter quickly.

I used a 3/8" bowl gouge to turn the whole thing, and found it often more accurate to use the wings of the gouge in a sheer cut to smooth the curves. Whatever tool works for you is the right one to use.





That's all for now, I'll continue this after I cook supper.

Reactions: Like 2 | Thank You! 1 | Great Post 2 | Way Cool 4 | Informative 2


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## woodtickgreg (Mar 4, 2021)




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## Steve in VA (Mar 4, 2021)

I've got to quit looking at your posts Tim! My list of things to try is getting longer by following you!!

Thanks for all the details on this! After seeing your collection on the drying rack, the thought of making one for every wood species I've used for something else crossed my mind. Might make for a very interesting collection over the years.

Reactions: Agree 2


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## trc65 (Mar 4, 2021)

I'm the same way Steve, going down this rabbit hole instead of working on a pipe! Nice thing about these are they turn rather quickly after you make a couple.

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## trc65 (Mar 4, 2021)

I just noticed that I took all these pictures while it was spinning. Wasn't intentional, but this way you can't see how good/bad some of the cuts were

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## trc65 (Mar 4, 2021)

Now that it is roughly sphere shaped, time to part it off, and use some wooden cups to refine the shape.





Here are a couple pictures of the cups I made. The first is mounted in the chuck for convenience. Made of hard maple, it's about 1 3/8" diameter. Didnt measure depth, but cut deep enough a cup so you dont bottom out with the sphere. The tailstock cup is about the same size, but it is threaded on a live center with 1x8" threads. You dont have to go buy the tools necessary to do this, lots of people have cup live centers, or you could just make one to sit over the live center point. You will want to think about the size spheres you want to turn before making these. If you make them too large, the cup will be in the way while you are refining the shape/sanding, and you will spend more time repositioning between cuts. I would guess a cup size about 1" less in diameter than the smallest you want to turn. I think one of the guides I read talked about sizing cups, but don't remember any guidelines.









Now, rotate the orientation of the sphere, and mount it snug in the cups. You'll find right away that it probably doesn't sit perfectly in the cups, or at least none of mine have. Just center it in the cups, and most importantly, snug enough it doesnt move. You can see the nubs from parting off, and got a little work to do in shaping the ends.





At this point in time you are going to spin it up and start removing the "ghost" image you see when spinning. At this point, don't try smoothing, or cutting too much down right next to the cups, if you do, it will throw it out of whack quickly. You want to focus on the top and maybe only going about halfway down towards the cup. Once you get the top smooth, you can make light cuts closer to the cups.

This picture is supposed to show the ghost image you want to remove, but doesn't show it too well. When you get close to having it right, the cut will smooth out considerably.

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## trc65 (Mar 4, 2021)

As you start cutting now, stop the lathe often to see your progress. You can see in this picture where im cutting on mostly the top. Stillhave a little way to go as you can see the dimple from the end. Notice that the center line is still present, that line represents the only true circle around the sphere. 



In this picture, you can see where I was a little off in shaping the ends. To get the two ends even, I had to remove just a little of the line. No worries, it will just be a tiny bit smaller.





Now that the top is even, you can continue the cuts down toward the cups to smooth out those areas. Once again, primarily using the wings of the gouge to make very light cuts. You can see where the cuts stopped just short of the cups.





Now, rotate the sphere 90° in the cups. Notice the raised area that was in the cup, that is what gets removed next. Ideally, you would still see the line all the way around, but since one end was off, had to remove a little more to even it out.





Here's another pic from a different angle showing what needs to be removed. As before, I found it easier to remove the top first and then move down the sides.

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## woodtickgreg (Mar 4, 2021)

Thanks for showing this! It's a very cool process.

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## trc65 (Mar 4, 2021)

Once you get that removed, here's what you have. I cleaned it after this picture with a neg rake scraper. You'll find it may not be perfect at this point, especially if you have a little wiggle, or don't have the cups perfectly aligned, no matter, an 80 grit gouge will fix it right up.






Here's a pic after the neg rake scraper. Pretty good! At this point in time, go ahead and rotate the sphere a time or two while you are cleaning it up.





Now it's time for sanding, I use the my right angle drill and 2" pads while spinning. The other thing I did was add some folded paper towel to cushion the sphere. The hard maple will burnish marks even on the hard Locust.





Rotate the sphere once or twice while sanding with each grit to make sure you get everything and move your way up to whatever grit you like.





I sanded this up to 600x and it looks pretty good.

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## Gdurfey (Mar 4, 2021)

Thanks for your time Tim. This is great. I tried one......and as I said, will try again!

Reactions: Thank You! 1


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## trc65 (Mar 4, 2021)

A pic just to show my lamp. It really helps to have an auxiliary light when turning these to help see the ghost image.





Here's the finished sphere sanded to 600x. I'll take a good look at it tonight and see if it needs some touch up before finish, but it looks pretty good. The best thing about these spheres is they are so tactile, it just feels great holding them in your hand! Will probably give this one about three coats of tung oil for a little shine. These look great with or without a finish, so do as you please. 

This one measured just a tad under 2 1/4" when finished, so i lost about 3/32" off the original diameter. As i said before, doesnt really matter, not turning these for any particular use.





To finish up, a picture of part of my audience. The shed cats like to stick close while I'm working in case I pause long enough to pet them.

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## ripjack13 (Mar 4, 2021)

Nice write up Tim. Well done. Now That I'm done with the pipe I should try this..

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## trc65 (Mar 4, 2021)

Go for it! I put off trying this for so long because some of the things I read made it sound so complicated. It really is a lot easier than it looks, and once you get a few under your belt, you can whip them out quickly.

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## trc65 (Mar 4, 2021)

Here are a couple of sphere turning guides.


Al Hockenbery has several guides on turning a ball/sphere on his AAW site. http://aaw.hockenbery.net/ I'd start here if you want some more info. Al is a great teacher and has spent a lot of time developing materials.

In addition, the AAW forum aawforum.org has numerous guides that delve into turning precise sized spheres. Just do a search over there on "turning a sphere". I'm not sure if you need to be a member or not to access that forum.

Reactions: Useful 1


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## Nature Man (Mar 5, 2021)

Your tutorial is well laid out and includes considerable detail. Thanks for taking the time with this! I'm trying to figure out what you used in your tailstock to make it grip the wood like a chuck. Where would I buy one of these? Chuck

Reactions: Thank You! 1


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## trc65 (Mar 5, 2021)

It's one of these.





Same threads as headstock. Tapped a piece of maple, screwed it on headstock, shaped the cup and then screwed it on tail stock adapter. Think PSI calls it a live tail stock chuck adapter. Several different manufacturers.

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## William Tanner (Mar 5, 2021)

Very informative.This is now on my short list.

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## barry richardson (Mar 5, 2021)

trc65 said:


> It's one of these.
> 
> View attachment 204559
> 
> Same threads as headstock. Tapped a piece of maple, screwed it on headstock, shaped the cup and then screwed it on tail stock adapter. Think PSI calls it a live tail stock chuck adapter. Several different manufacturers.


I was wondering what that was, do you have a tap to cut those threads into wood? I did a similar thing with my oneway tail center, the cone screws off and leaves 3/4 by 10? I think. bought a tap that size to thread the cup.... Excellent tutorial BTW!

Reactions: Thank You! 1 | Agree 1


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## Barb (Mar 5, 2021)

Another thing I've been meaning to try myself for awhile. Very well laid out tutorial! Now I have no excuse. Thanks for putting this together. :)

Reactions: Thank You! 1


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## trc65 (Mar 5, 2021)

barry richardson said:


> I was wondering what that was, do you have a tap to cut those threads into wood? I did a similar thing with my oneway tail center, the cone screws off and leaves 3/4 by 10? I think. bought a tap that size to thread the cup.... Excellent tutorial BTW!



Yes, I bought a Beall 1" x 8tpi tap the other day. Handy thing to have around to make some of these type specialized chucks.

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## trc65 (Mar 5, 2021)

ripjack13 said:


> Nice write up Tim. Well done. Now That I'm done with the pipe I should try this..





William Tanner said:


> Very informative.This is now on my short list.





Barb said:


> Another thing I've been meaning to try myself for awhile. Very well laid out tutorial! Now I have no excuse. Thanks for putting this together. :)



I was just thinking this would have qualified for the multi-axis challenge.

Reactions: Agree 3


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## ripjack13 (Mar 6, 2021)

trc65 said:


> I was just thinking this would have qualified for the multi-axis challenge.



Not really. Yes you're turning the object from different directions but its still on one center. If you adjusted it from that center like multi axis, that would certainly be cool looking. Like a river worn rock....

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## trc65 (Mar 10, 2021)

Two additional tips that just occurred to me today (as I was turning another). 

First, before you part off the sphere to start turning with the cups, hold one of the cups on the sphere and make sure the sphere seats securely in the cup. If it doesnt, correct the curve now, or you will be chasing the shape as it WILL shift in the cup while you are cutting. 

Al Hockenbery recommends using a slice of PVC pipe to hold up to the sphere to make sure you are properly rounding it.

This is a finished sphere, so it obviously fits well, but this illustrates the point. It doesn't have to be a perfect fit, it just can't wobble in any direction.






Second tip. When you get to the point of sanding, make a mark on one of your chucks. Then when you need to rotate the sphere during sanding, align the mark to the same place on the lathe each time you stop. Also, get in the habit of moving the sphere in the same direction each time you reposition it. This is more important as the spheres are closer in size to the cups. With the oak sphere above, I rotated it a little less than 1/4 turn each time and had to sand in three different positions to get it all.. You could always make different sized cups to better fit a size range, but I was too lazy to make more and used these cups for everything from 1.75" to 4.5" spheres.

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