A couple days ago I got 3 shafts from a friend for a routine turn-down. 2 came to me at 13.3mm. The other was huge at 14.2. These shafts were off cues fresh from the Philippines. When I say fresh I mean they have probably been in this country less than 3 weeks.
One shaft had a TINY roll so I did it first. If it had been any worse I would have not been able to turn it since it would not have cleaned up but it was just a few thousandths and I was going to remove quite a bit of material.
I don't know what anyone else does but If I'm removing a lot of material on a turn-down I treat it like a final cut on a shaft and go slowly, so I took a .2mm cut. Pretty conservative I thought.
I left the shaft on the machine over night; by morning the shaft was running out about 1/4mm. I let it sit a day for the hell of it and re-measured: still the same. By this time I had already selected a replacement blank which was ready except for a final cut ( I keep lots of these on hand ) 'cause I knew where this was leading. For the hell of it I took another thin cut. By that evening it was warped sufficient to shoot around corners. I've never seen anything like it.
So I suppose this was all fairly predictable; I'd heard about it but some folks like to knock everything imported so I had taken it with a grain of salt.
The signs were there for me to see: the ferrules were WAY bigger than the shafts, and the shafts were obviously not round because the flat grain and the edge grain shrank at different rates. You could feel it. They were all 0.1mm egg-shaped. But I could not believe they could still be that wet after all that shrinkage had already taken place. Wrong, wrong, wrong.
Obviously I passed on the other 2 turn-downs. Can you imagine what the 14mm one would have done?
Damn. I won't do THAT again.
Robin Snyder
One shaft had a TINY roll so I did it first. If it had been any worse I would have not been able to turn it since it would not have cleaned up but it was just a few thousandths and I was going to remove quite a bit of material.
I don't know what anyone else does but If I'm removing a lot of material on a turn-down I treat it like a final cut on a shaft and go slowly, so I took a .2mm cut. Pretty conservative I thought.
I left the shaft on the machine over night; by morning the shaft was running out about 1/4mm. I let it sit a day for the hell of it and re-measured: still the same. By this time I had already selected a replacement blank which was ready except for a final cut ( I keep lots of these on hand ) 'cause I knew where this was leading. For the hell of it I took another thin cut. By that evening it was warped sufficient to shoot around corners. I've never seen anything like it.
So I suppose this was all fairly predictable; I'd heard about it but some folks like to knock everything imported so I had taken it with a grain of salt.
The signs were there for me to see: the ferrules were WAY bigger than the shafts, and the shafts were obviously not round because the flat grain and the edge grain shrank at different rates. You could feel it. They were all 0.1mm egg-shaped. But I could not believe they could still be that wet after all that shrinkage had already taken place. Wrong, wrong, wrong.
Obviously I passed on the other 2 turn-downs. Can you imagine what the 14mm one would have done?
Damn. I won't do THAT again.
Robin Snyder