[Generic Default]

Hi everyone,

This is my first post on these forums but I've been creeping on you guys for several years. I have a decent amount of machining experience, more so with CNC than manual machines.

Anyway, I recently got a sherline 17 inch lathe. Everything works pretty well on it except for the chuck. Turning is fine, facing is fine, but when I try to part off any piece of bar stock, the bar stock somehow slides out of the chuck, as if it's being ejected towards the tailstock.

It happens with every material (several aluminim alloys, steel, brass, even PTFE) and with both round rod and hex rod. It does it with every diameter of bar.

I'm using a 0.04 inch parting blade, the flat T shape type. It does the same thing with the 0.06 parting tool also. The parting tool bends so much when the parts start to slip out that I'm afraid it's going to break, not to mention I have to re-chuck about 5 times just to part off one piece. I've tried tightening the chuck more and less, and I'm capable of putting a lot of torque on the chuck to tighten it so that isn't a problem.

Has anyone else had this problem? I've never seen it happen with any other lathe, and I still don't understand what's causing it.

Thanks!

[acannell]

Hi everyone,

This is my first post on these forums but I've been creeping on you guys for several years. I have a decent amount of machining experience, more so with CNC than manual machines.

Anyway, I recently got a sherline 17 inch lathe. Everything works pretty well on it except for the chuck. Turning is fine, facing is fine, but when I try to part off any piece of bar stock, the bar stock somehow slides out of the chuck, as if it's being ejected towards the tailstock.

It happens with every material (several aluminim alloys, steel, brass, even PTFE) and with both round rod and hex rod. It does it with every diameter of bar.

I'm using a 0.04 inch parting blade, the flat T shape type. It does the same thing with the 0.06 parting tool also. The parting tool bends so much when the parts start to slip out that I'm afraid it's going to break, not to mention I have to re-chuck about 5 times just to part off one piece. I've tried tightening the chuck more and less, and I'm capable of putting a lot of torque on the chuck to tighten it so that isn't a problem.

Has anyone else had this problem? I've never seen it happen with any other lathe, and I still don't understand what's causing it.

Thanks!

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[Fastest1]

Just to let you know, the parting tool is the most challenging tool to use with a Sherline.

[awerby]

Are you supporting the tailstock end of the part with the taistock center? That should prevent the piece from being "ejected". Or is the whole tailstock moving? In general, if you've sharpened the parting-off tool unevenly, it can have a pushing effect - you need to sharpen it flat to make it cut evenly,