I have a Jet 1014 (midi/mini) lathe and an 80mm axminster chuck with these jaws which grip down to about 40mm.
I was trying to turn a goblet from a piece of square soft pine (practice) about 100mm wide x 200mm long. So I roughed it into a cylinder, and cut a spigot on one end to fit the jaws of the chuck.
First problem - as soon as I have chucked the piece up, I then need to cut another centimer or so off the cylinder to get it balanced again. Is that normal? I technically have a perfect cylinder, with a perfectly cylindrical spigot on one end, and the jaws of the chuck should technically push it into a central position when gripping it, so I would expect it to be pretty much in the same position and pretty much balanced.
Second problem - when trying to hollow the unsupported end, the piece keeps suddenly shifting, or worse, flying off. No wonder they call it a 'chuck'. I have it well tightened, the spigot is as deep as it can be for this size of jaw, so I can't see how to make it any more secure. I've seen plenty of youtube videos of people doing it this way, so I am a bit stumped. The pine is quite soft, but then, I would have thought this would mean the jaws grip tighter if anything.
Any light anyone can shed on what I might be doing wrong, I'd be very grateful.
I was trying to turn a goblet from a piece of square soft pine (practice) about 100mm wide x 200mm long. So I roughed it into a cylinder, and cut a spigot on one end to fit the jaws of the chuck.
First problem - as soon as I have chucked the piece up, I then need to cut another centimer or so off the cylinder to get it balanced again. Is that normal? I technically have a perfect cylinder, with a perfectly cylindrical spigot on one end, and the jaws of the chuck should technically push it into a central position when gripping it, so I would expect it to be pretty much in the same position and pretty much balanced.
Second problem - when trying to hollow the unsupported end, the piece keeps suddenly shifting, or worse, flying off. No wonder they call it a 'chuck'. I have it well tightened, the spigot is as deep as it can be for this size of jaw, so I can't see how to make it any more secure. I've seen plenty of youtube videos of people doing it this way, so I am a bit stumped. The pine is quite soft, but then, I would have thought this would mean the jaws grip tighter if anything.
Any light anyone can shed on what I might be doing wrong, I'd be very grateful.