"Harold and Susan Vordos" wrote in message
...

"Gunner" wrote in message
news
On Wed, 02 Mar 2005 22:25:40 -0600, "B.B."
u wrote:

For class I'm turning an aluminum flywheel. 3" diameter. The steps
a face the sides, drill & ream the center, press onto a mandrel,
turn
the outside and sides. Anyway, after pressing it onto the mandrel
(yes,
I cleaned out the cutting oil) I've found that I have to go very slowly
or the cutting tool will grab the wheel and spin it on the mandrel.
What are some good ways to deal with this problem? I already
crammed
it as far onto the mandrel as I'm comfortable with. I'm tempted to
just
loctite the damn thing.

Superglue works quite well as long as you dont have any tool chatter.
So does regular fingernail polish.

I make my own mandrels by turning a rod to diameter, drilling and
tapping the end, then slitting with a hacksaw or slitting saw. Slip
over the workpiece, then installing a socket head cap screw in the
tapped hole to expand as needed.

Best if done in a collet of course. but works fine in a three jaw if
you dont remove it during any of the process.

Cheap and easy to make, grabs well.

Gunner

Works real well with a pipe plug, too. It's a good idea to try to make
your cuts at 90°, so when you expand the mandrel it does so uniformly and
retains concentricity. Rough turn, drill, tap, split, deburr the threads
with your pipe tap, then finish turn with the pipe plug tightened ever so
slightly. You can do surprisingly precise work with a mandrel so made.


The "splitting" part is what becomes the problem here--it's best done in
this case with just a plain ole hacksaw....with the mandrel still firmly
chucked in the lathe....

From start to finish, once you chuck your mandrel blank you should forget
that you even *own* a chuck key--throw the darned thing out the bay door and
retrieve it later......cause if you unchuck the work and have to re-set it
then all bets are off....

===

Never forget that turning or milling, makes no differance--your primary axis
is always gonna defined by your spindle bearings, and all other planes are
defined from that referance.

--

SVL