Re: [CAD_CAM_EDM_DRO] Re: Help needed with G code

Hi Jon,

Arc moves in two planes at once sounds like a neat math problem! Any
idea how it's done? I understand (and have implemented) moves in each
of the single planes. How often is something like this used? OK,
probably not necessary in a hobby controller!

R radius parameters are not that hard to implement, but I'm told they're
not always useable (or accurate for all arcs). The do appear to make it
easier to write arc blocks in an "interactive mode". I guess it just
depends on what you know about what you're drawing.

Adding a linear move along with an arc move is also not that hard
(helical), but I haven't made much use of it... yet.

Alan KM6VV


Jon Elson wrote:

>
> The standard definition for arc moves using relative offset coordinates is
> that I is the X offset to the center of the arc, J is the Y offset, and
> K is the
> Z offset. In general, most controls don't support arc moves except in on
> of the 3 planes, XY, YZ and ZX. There are more sophisticated controls
> that can do arbitrary arc moves in any plane.
>
> A lot of controls do not support arc moves with the R radius, unfortunately.
>
> So, to follow the language spec, an XY plane move may only have I and/or J.
> A YZ arc may only have J and/or K. A ZX arc may only have I and/or K.
>
> The plane of arc moves is specified by :
> G17 XY plane
> G18 ZX
> G19 YZ
>
> Jon