Re: Re: How does G02 & G03 work?

Subject: [CAD_CAM_EDM_DRO] Re: How does G02 & G03 work?

> From: Ray Henry <rehenry@...>
>
> BTW I've been thinking about writing some processors for emc that will fix
> nc differences and can be run from the tkemc program editor. Some are
> already working on this for mastercam. I'd need clear descriptions of

what

> code is generated by commonly used cam/?? systems. Need bobcad and vector
> using the closest post. ahha and flashcut. Any others. If you have such
> writeups you could attach to me, rehenry@..., I'd really appreciate it.

Ray,

Bobcad and Vector put out different values, depending on the settings
selected for a given "Post". I use the term post loosely, as neither has a
true CL file post processor, but rather convert directly from the drawing
geometry to G-code. All arcs except G17 are automatically interpolated into
line segments in Bobcad.

Following are Vector arc options in the iso driver, note that there are 3-4
other drivers for European controls that are not too common in the US:

Arcs

The direction of arcs (G02 or G03) is determined (as usual) by viewing the
arc from the positive Z axis.
The driver generates I, J and K values for every arc (may be suppressed if
not changed) . Please do not forget that arcs, which do not lie exactly in a
coordinate plane cannot be executed by the NC machine (mostly). You must
first interpolate such an arc before executing it. (until somebody comes up
with a control that can cut true 3D arcs, then you can use Vector to program
them)

Options for arcs, besides signed, relative or absolute - IJK:


G02/G03 arc with R instead of I, J en K:
G02/G03 X.. Y.. Z.. R.. to (2)
Automatically divides complete circles into two semi-circles.
R positive: angle less than or equal to 180�
R negative: angle greater than 180�

G25 fillet between two lines:
G01 to intersection (4)
G25 R...
G01 to end point (3)

G06 tangential from line to point:
G01 to start of tangential arc (1)
G06 X.. Y.. Z.. to end point (2)

G26 fillet between line and line or arc:
G01 to end point fillet (2)
G26 R..
G01/G02/G03 etc.

G27 fillet between line or arc and line:
G01/G02/G03 to start point fillet (1)
G27 R..
G01 to end point (3)


Best Regards,

Fred Smith
IMService

imserv@...
Phone: 248-486-3600 or 800-386-1670
Fax:248-486-3698