[icecats]

Hello,
I am new to turning and lathe work and am having a pretty serious problem. I am attempting to turn 1" diameter, 3.5" long aluminum round stock in my Grizzly G0765 7"x14" lathe. I clamp the stock into the standard 3" 3 jaw chuck and tighten it as much as I can. I then proceed to turn and face as normal. However, if I take too large of cuts (maybe between 1/16" and 1/8"), the work comes loose in the chuck. This has happened twice; the second time the stock jammed, stopped the motor, and stripped the drive pulley. I feel like my depth of cut and speeds were very reasonable. Further, the stock was not sticking out of the chuck very far. I realize that this is very dangerous and am in need of some suggestions.
Thanks

[KH0UJ]

Any machining work is considered dangerous sir you just need to live by it, tighten it again with a bit force compared to the previous, by and by you`ll get the rhythm of the job

[bostosh]

how deep is the material into the chuck jaws?

[icecats]

how deep is the material into the chuck jaws?

As deep as it will go- about .75" . After that, the chuck bore gets too small to fit the stock.

[Jim Dawson]

!/8 inch depth of cut is a lot for that lathe. Try gently facing the stock, center drill, and use the live center in the tailstock. Normally you don't want unsupported stick out of the chuck more than about 3 diameters or a couple inches unless you have a lot of material in the chuck. With a max of 3/4 inch, that is not much to hang onto.

[RCaffin]

Tailstock
Tailstock
Tailstock

Slightly suicidal without one.

Cheers
Roger
(Or very, very shallow gentle cuts.)

[new2cnc4]

Tools is sharp?
tool is on center, or just a couple of thou. below?
what speed are you running at?
do you have a pic of the tool up against the material that you can post.
sometime a picture is worth a thousand posts :

[awerby]

It sounds like you're cutting on it when it's sticking out 2.75" from the chuck but only holding onto .75". That's too much; the leverage is working against you. Like RCaffin says, you need to support the far end with your tailstock. Typically, you would use a combination center-drill countersink to put a tapered hole in the end which a live or dead center mounted in the tailstock would fit. Tighten it down so that it doesn't rattle but still can spin, then you should be able to turn the outside with confidence.