Cydrome Leader fired this volley in news:kjknae
:

Is that about right?

There's an awful lot that can go wrong on a light "hobby" lathe. Banquer
said it right, about having to "baby" it to prevent flex and spring. The
other responses about spring in the system were also spot-on.

Also, if you're using a lantern toolpost, it's hard to control the rake
without re-grinding the cutter. Raising and lowering the tool only serve
to alter it's "cut per increment".

It's not "kosher" on aluminum to use a zero back-rake, but it will tell a
tale if you try it. The finish won't be all that great unless you use
high speed and have a VERY sharp cutter, but if the problem goes away, it
indicates that hogging (due to spring in the system) is the problem.

A zero back-rake springs away from the work -- if it's precisely on the
centerline.

You might also check your mounts. If the whole bed can spring and twist,
it will give similar disgusting results.

Lloyd