On Wed, 7 May 2008 20:08:15 -0700 (PDT),
wrote:

I have an aluminum tube that I need to bore about 1" at end out to at
least 5.57" -- it varies from about 5.47" to about 5.60".
Unfortunately, this is too big to put on my Sherline lathe--it won't
fit onto the outside of chuck that I can find for the Sherline. I
have this vague notion that there might be some way to do this by
putting an end mill in the headstock and rotating the workpiece so
that the end mill removes a fairly consistent layer. This doesn't
have to be spectacularly precise. I tried this approach, and except
that I couldn't figure out a way to get the workpiece to turn
consistently (since it wasn't supported), it almost seemed to work.

Does anyone have any clever ways to do what I am trying to do, without
breaking down and buying a bigger lathe? Some clever way to mount the
tube on a 3.5" OD chuck, for example?


If you can find a way to clamp the tube on the compound so that it is
centered vertically on the headstock center (you an align it
horizontally with the cross feed) you could make a fly cutter sort of
tool to bore the inside of the tube.

Or use a four jawed chuck, maybe with the jaws turned around and some
blocking to hold the inside of the tube while you bore the other end.

Or machine a two diameter arbor. The larger diameter presses into the
tube, the smaller diameter fits your chuck.


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)