About 4 years ago I bought a used 13 X 40 Jet lathe. Sweet machine compared to the Smithy 3in 1 I had. It came two three jaw chucks and each of them had 20 mill run out. I bought a new cheap 3 jaw and was thrilled to see it had about 2 mill run out until the 2" diam Al rod jammed when I was parting it out. Now I have 3 cheap 3 jaw chucks with 20 mill run out.
The new chuck (Christmas present) is arriving in a day or two and it is supposed to be a step up from the cheap ones. I am also going to be way more carful doing cut off operations.
Anyone have some rule of thumb for cut off operations? ===========================================
I'm not really a fan of parting, except on tubing. Thick solid stuff is a pita. Imo, better to cut thick stuff on a saw (band, RAS, abrasive, whatever does the job), and then face it. But then, ahm no 'spert, I just get thru the day.
Lest the 'sperts don't reply:
Don't have the parting tool too low below center. Don't have it stick out any farther than necessary. Be prepared to move the carriage in X bec of tool drift -- I've never parted anything that didn't wind up convex or concave, unless it's very small diameter, or tubing.
Make sure you have the right rake etc on the tool. Use oil, coolant, make sure rpm is appropriate for mat'l, diameter. Some people don't realize that even tho alum is easy to work, it's low melting point/gumminess can cause its own problems with tool breakage. So watch the rpm on large diam stuff.