Dumb Turning Question

[HimyKabibble]

I'm doing something perhaps a bit goofy, but....  I need to make a batch of parts that basically look like a tootsie-roll pop - a cylindrical section, with a sphere on one end.  The cylinder is roughly 1/2" diameter, while the sphere is 1" diameter.  The goofy part is I'm doing it on my 3-axis mill, with a lathe tool clamped in my vise, since I have not yet gotten around to CNC'ing my little lathe.  I've got it programmed to do the right motions, but it appears to me it's not really practical to do this without using at least two tools - one right-hand, one left-hand.  Use the RH tool to cut the bottom half of the sphere (up to the "equator"), and the LH tool to cut the top half of the sphere.  Either tool can be used to cut the cylinder.  Is there a better way that I'm not seeing?

Regards,
Ray L.

[Hood]

Button tool or  a neutral VNMG type.
Hood

[Hood]

Oh just reread think its a full sphere on the end of the cylinder, you would need the button as VNMG wouldnt work.
You also get MDT tools which are sort of like grooving tools which would work as well especially if you need a tight radius at junction between cylinder and ball.
Hood

[HimyKabibble]

Hood,

If I'm understanding you....  You're suggesting using a tool with a circular profile, then program the movement along a circular path whose radius is the sum of the radii of the sphere being cut, and the radius of the tool?  Why didn't I think if that?  :-)

Thanks!

Regards,
Ray L.

[Hood]

Sounds about right

I do it with CAM so its simple
Hood

[HimyKabibble]

Yes....  I can tell you, without CAM, generating the toolpaths is a PITA!!   

Regards,
Ray L.

[RICH]

Ray,
If your going to try and cut the ball profile in one continous movement ( finish cut ) about the only tool that will do it is a point tool ie; has a radius ground on both sides and the radius is bigger than the ball. Otherwise it will gouge the piece. Have seen but never done what your doing. BTW, may be able to manipulate the code generated from LazyTurn via axis substitutions. Beats hand
coding it maybe. Best to get that lathe CNC'd....

RICH

[Hood]

Yes few mins in CAM and its done, best £200 I have ever spent, well apart from money I have spent on Mach and machines themselves.
Heres a few screenshots to annoy you

There is also what is called  Form tools and was a big thing before CNC but no way your mill is rigid enough for that as they have the profile in them and you plunge in to form the ball..
Hood

[HimyKabibble]

Hood,

Yup, that looks exactly like what I need to make.  I've already hand-coded some parameterized G-code to do the job, with parameters for the sphere diameter, tool tip radius, etc.  May get to give it a try later today.

Thanks!

Regards,
Ray L.

[Hood]

Ray, I could CAM it for you if you wanted but it would be all metric and my post processor is heavily modified for my lathe although likely that wouldnt really matter too much as it would only be one tool being used.

Hood