Hello Graham,

You can make a swinging cutter for balls that works quite well. It is described
in David Springett's book, "Woodturning Wizardary." You can also purchase a
metal version from Craft Supplies Ltd. in the UK, it is called a sphere turning
rig.

Basically, all you need to do is make an "L" shaped piece out of a good hard
wood. Put the long side of the "L" on the lathe bed with a hole through it and
some means of locating the hole on the center line of the lathe (i.e., directly
below the headstock center). On the one that I made several years ago, I used
two bearings one below the lathe bed and one above it so that a bolt passed
through the hole in the "L" would pass through the bearings and would swing
freely and smoothly. When this is done, locate a spot that is directly on center
on the upright leg of the "L". Drill a hole to accept one of your round cutting
tools that has the cutting edge at centerline of the tool (this is so that the
cutting edge is on center line of the axis of rotation). Now drill and tap a
hole from the side or top that will intercept the hole for the tool. Insert the
tool in the hole, insert a short bolt that matches the threads in the "L" and
use it to secure the setting of the tool. You can now get nearly perfect
spheres, by adjusting the fixture so that the point of swing is directly below
the center of the ball that you want to turn. Adjust the tool so that it just
cuts on its furthers swing to either right or left. Swing to the other side and
cut, then move the cutter in a bit and repeat this overation until you cut
across the top and the sphere is to proper diameter.

Another way is to clamp the wood in a chuck and locate the center of rotation
1/2 of the diameter from the end of the wood. You have to cut up hill on half of
the cut, but it makes a perfect sphere of the diameter that you want.

You might find it less expensive to purchase already turned spheres, however. I
personally like to turn my own. Good luck with your project.

Fred Holder
http://www.fholder.com/

In article , "Graham says...

My appologies for posting the subject for a second time but I am still
searching for a relatively simple approach to this problem. I need to turn
fairly regular high (100+) volumes of 40mm dia spheres in soft woods for use
in a variety of toys that I make. They don't have to be "perfect" but they
need to look "OK". I curently just turn them using a spindle gauge. Single
piece blank to diameter then mark length. Plunge at length each end then
half bead left then right. If I am on song then they are great ... but I am
seldom on song.
I have seen plans for several complicated devices to make and attach to the
lathe but never attempted to make them.
Surely this problem has been solved in the past. I would be grateful for any
simple solutions ( on topic). eg would a set of LH & RH curved (20mm radius)
scrapers work? If so how would the tool be sharpened and re-sharpened?
regards,
G