I was asked to help out on a rush job for an agricultural engineering firm I do a bit of turning for,
Usual cardboard cut out pattern and a rough sketch!!
Quite often you never know what these things are for, but it was for a pilling rig mast foot!
Having done a lot of contract welding for a pilling firm I knew exactly where it went!
For scale the ball is 5" diameter.
The owner of the firm was shaking his head as many years ago when they brought the lathe second hand it had a copying attachment but the guy wanted as much for it as the lathe so they never brought it!
I made a radius tool at home with some carbide I've had for years...
The rest was all by eye and the cardboard pattern...(the spare I will do next week)