Re: [atlas_craftsman] Re: Making a ball turning attachment.
- In a message dated 3/1/2005 1:41:20 AM Eastern Standard Time,
> Hi Gang,
> I am at abit of a loss as to hoiw using the lantern
> tool post would work. You could definitly cut a
> concave radius like that, but the deigns that I have
> seen for radius cutters all have the point of the tool
> behind the axis of the holder. The distance would
> determine the radius of the sphere being cut.
> That is what makes building one a trifle more
> complicated. Sherline mini lathes have one as an
> attachement that mounts to the cross slide and is
> moved verticalls, which if you stop and think abput it
> for a second, it makes sense.
While you can't withdraw the compound rest enough to get the tool post in
front of the axis of the compound swivel (between the operator and the swivel),
you can advance it well past the swivel axis.
That gives you two options. You can cut on the back side of the workpiece,
or flip the compound around and cut on the front side. If you opt to cut on
the back side, you can do it with the lathe in forward and the cutter upside
down, or with the cutter in the normal position and the lathe in reverse. If you
choose the latter, just be careful that the chuck doesn't unscrew.
A pro would of course use a ball turning attachment, or a CNC lathe. An
amateur sometimes has to be a bit more clever.
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> That gives you two options. You can cut on the back side of theworkpiece,
> or flip the compound around and cut on the front side. If you optto cut on
> the back side, you can do it with the lathe in forward and thecutter upside
> down, or with the cutter in the normal position and the lathe inreverse. If you
> choose the latter, just be careful that the chuck doesn't unscrew.lathe. An
> A pro would of course use a ball turning attachment, or a CNC
> amateur sometimes has to be a bit more clever.I couldn't help but comment on John's suggestion of swiveling the
> John Martin
compound. My grandfather (a highly skilled machinist) taught me how
to do this when I was about 13 years old. I made a couple nice
spheres and replacement knobs this way.