On Mon, 02 Jan 2006 16:10:31 GMT, "Lloyd E. Sponenburgh"
wrote:


In article , Gunner Asch
says...

Dont cut off aluminum slow. You can do it at least 500- 800 rpm. And
make sure EVERYTHING on your lathe it locked down, including the
carraige. Aluminum can also..sometimes..benifit by putting a bit of a
positive rake on the end of the tool. Not a lot..but some. Couple
degrees worth. and grind a smidge of relief just behind the cutting
edge so its a very small inverted V with the wide ends of the V doing
the cutting.

The biggest problem I've experienced on small machines (even with the cross
slide gibs tightened) is that even a little hogging will take up the lash on
the crossfeed screw, resulting in a lot of hogging... so raking the bit is
out for my little 6" lathe. The 14" seems not to care.

LLoyd

True enough. When I had my old tired Logan 10, I somehow or another
managed to cut off with a slightly negative tool. Mostly because I
kept burning up cut off tools, before I had learned anything. It also
gave me a decent enough finish with negative rake tooking, if I did
press too hard. Back carragie "ways" were pretty tight, and it didnt
lift the back of the carraige, so I could get away with it.

But aluminum is pretty easy to cut off. Now that 3" chunk of
chromemolley I cut off last night..boy howdy..that was interesting
getting the cut started...then I had to keep pouring the feed to
it..cut pretty nice once I found the magic feed rate..which of course
kept increasing the deeper I got.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner