Re: [CAD_CAM_EDM_DRO] Rope turnings in wood.

Roland Jollivet wrote:

> That sounds like a hellish amount to pay for a machine that could be made
> for $2000 or less.
>
> If you consider that a router is generally hand held, the forces on the wood
> are very low. Sure, you don't want it to dig in, so it has to have resonable
> rigidity, but the parts are simple.
>
> Roland

Actually, using my understanding of lathe CNC terminology, the "Z" axis
is parallel to the headstock spindle and the ways, the "X" axis is
perpendicular to the "Z" axis and parallel to the floor, think of it as
the cross slide.

The router should be mounted with the bit parallel to the "X" axis,
think of mounting it on the cross slide with the centerline intersecting
the centerline of the headstock spindle.

Based on the above and what he appears to want to do, it sounds like the
spindle will need little power, just good rigidity and low speed. With
low backlash, the system is simple and reasonably easy to build. I am
not so sure about the g-code writer since the "Z" axis wraps.

Practically, an 18 tooth and a 10 tooth pulley (with belts) on a 200
steps/rev stepper should give 1º/step at the spindle. With
microstepping (e.g. 10X on Geckos, 8X on many others, etc.) the
resolution should be quite good (under 0.002" on a 3" workpiece) which
should give good results. Is it a good idea? I don't know, but I would
guess so.

However, making your own ways, etc. is more work than reusing a clapped
out lathe, IMHO.

There may be better ways (from the software view) than using standard
lathe nomenclature, however. Calling the "Z" axis the "A" axis for the
purposes of software ("Z" is often linear, "A" is rotary), which may be
contrary to lathe terms, better describes the function of the axis from
a router standpoint and potentially from the software standpoint.

--
David G. LeVine
Nashua, NH 03060