Totally new to metal turning on an engine lathe. Bought an inexpensive
(read cheap Chinese) Grizzly machine which is about all I really need
for my hobby type projects but - seems to me I'm getting way more
chatter trying to turn stuff than even this machine should produce.

I'm trying to turn a grooved disk, 3" in diameter. I faced off a piece
of stock (in a three jaw) and turned about 2" reasonably true. Then
took an old carbide cutter my brother gave me, looked something like a
thread cutting tool, and ground the end to about a 3/8" radius. On a
green wheel, of course.

If I 'touch up' the tool on the ginder, go back to the lathe, I'll get
a really nice curly chip off the stock at first then the tool will
start to chatter and I'll get a whole mess of little semi-circular
shavings, if you will.

I've checked and rechecked the tool for center and it's as close as I
can get. This chatter occurs with or without lube. (Using Lennox
ProLube applied manually).

Am I just asking more of this lathe than it can produce? It's the
12x36 Grizzly gear head model.