So, now that I have this 4th axis, and it works, however badly, I
wonder how to I attach parts to it.

I have a 10 inch three jaw Cushman chuck and some smaller lathe
chucks. I think a 7 inch plain back chuck.

This would seem to be quite acceptable for things such as making
gears, and whatnot?

The 10 inch Cushman, of course, is kind of hard to center because it
is so heavy.

i

Ignoramus30636 wrote:

So, now that I have this 4th axis, and it works, however badly, I
wonder how to I attach parts to it.

I have a 10 inch three jaw Cushman chuck and some smaller lathe
chucks. I think a 7 inch plain back chuck.

This would seem to be quite acceptable for things such as making
gears, and whatnot?

The 10 inch Cushman, of course, is kind of hard to center because it
is so heavy.

i

This is entirely dependent on what you are making. You could have a
chuck on the RT, you could have a part clamped to the RT with the usual
clamp bars, step blocks and studs, you could have a collet closer
mounted to the RT, or you could have a custom fixture mounted if you are
making a lot of parts. What would not be common would be mounting a vise
to the RT since it doesn't really provide alignment suitable for an RT.

Ignoramus30636 fired this volley in
:

This would seem to be quite acceptable for things such as making
gears, and whatnot?



In addition to what Pete said, it also depends upon whether or not you'll
machine all surfaces. If you start with slightly oversized stock, a 3-
jaw will be more convenient; so long as it's tight, the work will
ultimately be centered as well as the run-out of your table, not the
chuck -- because you'll be machining off any "out of roundness" to the
piece.

If I'm machining (say) a hex profile from round stock, I start out with
stock only a few thousanths greater in diameter than finished piece. I
know my 3-jaw will center within a couple of thousanths, and the milling
takes up the "slack" in the precision of the chuck.

If you're doing spot-work on an already-machined piece, you'll need more
precision, which you can get with a 4-jaw and some indicator work.

LLoyd