Ball turning attachment - operation of

Hi all, im making a ball turning attachment. In terms of design and operation its similar to Anorak Bobs. I have a question relating to their operation, what is asjusted when taking successive cuts, is it the cross slide or the radius adjustment on the tool? I always thought you adjusted the radius down as you went until you got what you wanted but I see many dont have a fine adjustment or threaded adjustment on the cutter position. Those that do, often have the adjustment on the chuck side in order to allow more room for adjustment. This would be ok if I knew I didnt need to access that after every cut. So I assume that the cross slide is adjusted with successive cuts?



Cheers.



Simon