RE: [CAD_CAM_EDM_DRO] Re: Eccentric turning using CNC

Hi Roger, and the original poster,

Maybe the original poster (I've lost his name) is trying to make a simple
eccentric, like on a model steam engine. ;>)

If so, then an eccentric is a simple round bit of shaft, but drilled
off-center. If the contour (circumference) is other then round, it should
probably be called a CAM.

For turning on a lathe, one simply turns the stock 'round first, then offset
it 1/2 the desired throw in a 4-jaw chuck. The task can even be done in a
3-jaw chuck if a carefully chosen spacer is used. Really doesn't require
CNC!

Is it a CAM or ECCENTRIC? (Or something else?)

Roger,

Ornamental turning could be quite interesting. Definitely something CNC
could get around! Ask for Phil on the SBMETAL list, he's building an
ornamental turning machine, and he and I had talked about adding stepper
motors to it (or adding stepper motors to just about anything, a local club
joke).

Alan KM6VV

> vrsculptor
>
> Hi,
> Are you thinking about the oval/square type turnings that were done
> way back when on special lathes?
>
> If you are I think it could be done (in theory) if you treated your
> spindle as a rotary table and the cross slide as either the x or y
> axis on a mill. There are some interesting challenges to this approach
> such as how you run your spindle like a rotary table as the spindle
> motor is usually not a servo. I once saw a British rig where they just
> attached an indexing head to the end of the spindle for precision
> positioning.
>
> If you are looking at doing this kind or ornamental turning I think I
> would look into using a rotary table on a mill. I know that this is
> cheating but it is probably the most worakable approach. With ball end
> cutters you should be able to do anything the original machines did.
>
> Roger
>