"Michael Koblic" wrote in message
...
I have sort of worked out the headstock which should spin things as low as
60 rpm.
I am kind of stuck with the tooling side: the carriage, crosslide etc.
One of the questions I am struggling with is the size of the tooling
appropriate for this job (turning disks up to 9" in diameter).
Instinctively I feel that a 3/16 tool is not going to cut it (sorry about
the pun). But am I right?

One of the things of concern is a tool's ability to handle heat. Small
tools dissipate less heat, thus are prone to overheating, and failure.
Same goes for the grind of the tool. Too slender of a cutting edge can also
lead to premature tool failure (assuming HSS).

If you were to machine steel at recommended speeds and feeds, using brazed
carbide, it's possible you could actually soften the silver solder to the
point of tip failure when running small shank tools. Use the largest you
can accommodate, especially if you can move up to 1/2" sizes. They are far
more robust, and should serve better than small tools. Their greater
thickness of carbide, and larger size, are a good offset for the higher
price you will pay. The added rigidity is a bonus.

Harold

I have a boxful of 3/16 and 1/4" tools, toolholders with carbide inserts,
toolposts and something which I take to be a crosslide of some sort into
which all these things fit. They all look rather puny. Would they do a job
of truing up the edge of a 9"x 1/4" disk? Would they face it? Or should I
design around something more beefy? If so, how much more beefy?

--
Michael Koblic,
Campbell River, BC