Here is what I’m trying to make
I tried my ball cutting jig today to see if it would work. If you remember, I built the jig from the plan in the book ‘Woodturning Wizadry’ by David Springett.
Work piece mounted on the lathe. 12cm (4”) long.
work piece marked up 62mm (about 2-7/16”) and with a center line. The centerline stays on until the ball is entirely sanded, polished and after marking up for drilling of the various holes.
cut to the width (Ball diameter) As you can see, the axle on the left is longer for access by the ball cutting jig.
Check chuck centering (left side)
Check chuck centering (right side matches left side.)
Cutting after about 10 minutes
Close to finished after about 50 minutes total.
After some sanding and cutting down the ‘axles’
A little test to see that it actually is round (except the axles)
1. How good is this Cutter?
On the Negative side, this jig is pretty flimsy, but it does work. I had to hold it down with one hand and hold it steady as I swung it with the other. My locking mechanism for the cutter has to be locked really tight or it will loosen and it backs out of the cut when it does. The cut wasn’t as smooth as I would like, but nothing so bad it couldn’t be sanded out.
On the positive side, it does more or less guarantee a perfectly round ball. This is a big advantage for this work, where high precision is a must for a good result in making a Chinese Ball.
2. A better alternative
Turning balls by hand or with a jig is not especially interesting or fun. A jig is therefore a great advantage as it is precise. Better tools always do the job better and usually faster too, so I think I will probably make a heavy…ish steel jig for this work with a screw type advancer for the cutter, and while I’m at it I will probably want it to be extendable in order to do larger work in case I get an obsession for big balls (unlikely, but one never knows).
Now all that remains to finish this ball is to part it off and turn off the small nubs left over from the ‘axle’. This isn’t as easy as you might think, but it’s not astrophysics either, so I will show you the rest as soon as I can get back into the shop.
There are lots of ways to hand turn these balls and lots of different types of jigs to do it that way. The way I’ve shown here is just one way and certainly not the best, but it works. I will just stick with it until I can make something better. I wish I could do welding as this would be an easy way to make a steel jig. Anybody with ideas on how to make one without welding, please let me know. I’m not keen on learning welding either as I would probably burn the shop down and the house along with it.
Thanks for reading and any observations positive or negative are welcome, as long as it doesn’t have anything to do with sharpening! The following links cover all the blogs in the series to date.
-- Mike, American in Norway The four steps towards competency: 1. unconscious incompetence, 2. conscious incompetence, 3. conscious competence, 4. unconscious competence