[john lucas]

I turned these spheres this morning for my friend Pat Matranga. She broke her arm and had some rush jobs to get out so I volunteered to turn the spheres. They don't have any finish on them. the big one is Cherry and it's 4 1/2". The smaller ones are Hackberry and they are 3 1/2".

 

[Bonanza35]

Those are fantastic. I love that spalted hackberry. What are these used for and how dry is the wood?

 

[Nate Bos]

they are great! really do a nice job of displaying the wood!

 

[john lucas]

The wood has to be perfectly dry for these. My friend makes trophies out of them. They might go in a display case so the wood needs to be really dry.
You can make spheres from green wood but they will definitely warp and probably crack. Sometimes that's a good thing.

 

[duncsuss]

Really nice, John -- I've tried making spheres a couple of times and it's nowhere near as easy as Ernie Conover made it look when he demonstrated it :laughing:

 

[JTTHECLOCKMAN]

Hello John

These turned out real well. Are you using your new gadget to turn these??? Now that you tested it is there any pros or cons you can share with us about the tool. Could you give us the name again?? Will that tool fit on a mini or midi lathe??? Any does or don't's with it??? Thanks for showing.

 

[john lucas]

A long answer to your question. If it doesn't answer all your questions feel free to write me.
Version:1.0 StartHTML:0000000167 EndHTML:0000009522 StartFragment:0000000484 EndFragment:0000009506 P { margin-bottom: 0.08in; }A:link { } Sphere Turning Jig Review
By John Lucas




I just finished working with the sphereturing jig that allows you to turn balls or spheres of various sizes. I thought I would give my impressions of the tool. Www.sphereturning.com I have no affiliation with the company and simply borrowed it from a friend who purchase one.
First off when you pick up the box you notice it's quite heavy. This is even more noticeable when you pick up the parts and start assembling. It is made out of a large chunk of aluminum and the round parts are all steel. It is very well made and should last a lifetime. Everything fits perfectly. In fact I had to wax the two swiveling parts that fit together because they fit so well it was kind of difficult to remove and install them. A little wax made them work perfectly and you can feel the quality.
It has 2 bearings in the swiveling part and only has very slight flex which is pretty impressive since the bottom aluminum piece is about 10” long and it would be easy to get quite a bit of slop out of it if it wasn't built so well.
The cutter height must be set but it is very easy to do. There is a locking collar that goes against the top piece to lock the height into position so this is only necessary once. The top section can then be removed and reinstalled as needed and aligns perfectly.
The cutter is a 1/2” Hunter carbide cutter mounted with about a 12 degree forward tilt. It cuts very well when used flat with the cutter facing up. The part that holds the cutter shaft has 2 more flats milled on it's top. This allows you to angle the Hunter cutter left or right for a superior cut. This tilt does improve the cut. I turned a punky box Elder piece this morning and they can be a bear to cut without tearout. In the flat position I did get tearout. It was easily cleaned up by using the tilting technique. Harder good quality woods cut quite well with the cutter in the flat position. When tilted I was able to sand with 220 grit on all but one of the spheres I turned using this tool.
It is a little difficult installing the unit on the lathe. That is because the bottom plate that locks under the bed is kind of small and a little difficult to hold in place while you tighten the bolt. After installing it several times over a few days I got pretty good at it. It can be a little tough on the fingers tightening the bolt when first installing the jig. Obviously once you get it installed it's very easy to tighten and loosen using a wrench.
It's fairly easy to locate the unit accurately under the sphere center line. Just loosen the locking bolt a little and tap the base plate until the unit aligns with the center line. You can use a square or a plumb bob to align it accurately.
I rough turned the spheres first and then installed the jig. It was very easy to move the cutter into the piece. Swing the jig left and right to remove wood and cut the sphere. If the cut isn't clean enough tilt the cutter to the right using the top adjustment knob and then make a cut or two going to the right. Then adjust the cutter tilted to the left and make several passes to the left to clean up the ball. It's very easy to merge the two cuts because the jig is quite accurate. There is a very slight flex to the jig. I used this to my advantage. Lift up while making the final passes and the push down to bring the cutter back to the zero position. This way it won't cut on the way back up the sphere. Tilt the cutter the other way and push down as you cut the other side of the sphere, and push up when going back to center. This method leaves an extremely accurate sphere. A friend was over who needs spheres to be as close to dead on as possible. We didn't have a super accurate way to measure but using dial calipers measured them to with .010” of perfectly round and with .005 of the same size. Even if you add in some slop for our less than dead on way of measuring that's pretty darn good.
Used with the cutter assembly aligned perpendicular to the sphere will leave some fairly large tenons on both sides due to the jig hitting the tailstock or headstock. To get around this problem you can rotate the head of the piece left of right of the center line. (this is one advantage of the locking collar you adjusted when you first set up the machine) Rotate it about 15 degrees to the left and it lets the cutter reach much deeper into the tenon on the left side. Rotate it right about 15 degrees and you can do the same thing on the right tenon. If you remove the tailstock you can cut all the way to the center of the sphere when doing this. I was able to make a complete sphere with nothing but a 1/2” tenon on the headstock side using this technique. It's fairly easy to leave the tool rest and banjo on the lathe. The top part of the jig can easily be removed so you can use regular tools to reduce the tenons before cutting the sphere off.
Then you mount the ball between to cup centers and turn away the tenon or tenons. You can do this with the jig by very carefully aligning the jig to the newly mounted sphere. I found this kind of tedious and since I turned the sphere all but one half inch tenon it was faster for me to just turn the tenon away by hand. This is similar to turning an entire sphere by hand where you just remove the shadow or ghost area that appears.
With care I was able to turn a sphere that was less than .010” from perfectly round. You can also make multiple spheres pretty much dead on size wise. There is a stop for the cutter depth that you can set. This lets you make multiple spheres to the exactly the same size. Ideally I would like to see the cutter adjustment screw fastened to the cutter bar so they don't slide seperately. Add 2 locking nuts to the cutter adjustment screw and you could be very accurate in repeating your sphere sizes. Without this locked together system you have to be careful to push the cutter bar against the cutter adjustment screw or your size could be off.
The jig has 3 holes to allow you to turn spheres from 1” to 14”. You can also hollow out spheres using the jig to hollow each half. Then glue them together and turn the outside using the jig.
I was very impressed with the jig. It's easy to use and everything works quite well. If I nitpick at all there are two small things. The knob you loosen to move the cutter in and out locks very firmly which is good. However after you make a few spheres it starts to hurt your thumb and fingers. It might be a good thing to knock the corners off the knob a little to make it less sharp.
The other thing is the cutter bar is not locked to the threaded adjusting knob. If you don't have the top locking knob locked and lift the cutter assembly off you can drop this cutter bar on the floor and damage the cutter.
There is an excellent video on the tools usage that is on the website listed above. If you watch it you will get much more out of this review.
All in all a pretty nice machine that does exactly what it says it does and is fun to use. I think I'll turn a few more spheres before I return it to my friend.