Re: Interplotation?

John,

Turn one knob and you have plus and minus direction in one axis. Turn
the second knob and you again have plus and minus direction in a
second axis. These two axes are usually called x and y , and are at
right agles to each other. Anyway, the two directions of each axis,
times the two axes, make the four directions available with one knob
AT A TIME.

Parabolic interpolation is the SAME as circular interpolation, EXCEPT
the curves are parabolic, rather than circles or arcs.

Note that the axes do not "tip". They are, by definition of Cartesian
coordinate space, always at right angles to each other. Start with
the xy plane described above, and "shoot an arrow" through the point
where the xy axes cross. The arrow will represent the z axis. the
point will be in the minus direction and the feathers will be in the
plus direction.

Any point in space can be defined in terms of where it lies with
respect to these 3 axes, x,y,z.

Our milling machines are normally set up with the xy plane as the
work surface. The tool is carried by the Z axis and moves toward and
away form the plane of the xy.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., <e.heritage@b...> wrote:
> Ballendo,
>Thanks for the descriptions of interpolation. They do indeed sell
>ech-o-sketches here. You said in the very beginning of your reply
>that if I was to imagine a machine with just the X and Z axis then
>turning one of these knobs would move the pen in four directions.
>Wouldn't it be turning both the knobs at the same time? Turning just
>one will only move it along one plane so it would only have two
>directions.

Turning just one knob will move in a LINE. Adding the LINE formed
when you turn the second knob will define a PLANE.

>I have absolutely no idea what parabolic interpolation is all about
>but I will have a guess and you can tell me how many miles I'm off.
>Is it that the Z plane can also be tipped on it's axis to form
>curves that are vertical to the bed.
<snip>
> John