Re: G Code questions

--- In CAD_CAM_EDM_DRO@y..., Ethan Vos <ethan@f...> wrote:

> I need to cut and arc of about 55 degrees with 4 or 6 passes

of .003 each.

> There are six of these arcs per part, so 36 passes.
>
> Is there a repetitive cycle that will do arcs?
>

Nearly any CAD system will allow you to draw using arc beginning and
ending in degrees. You can usually inquire as to the exact locations
of the end points, or else snap points to the ends of the arcs and
then inquire as to the value of the points. The Vector Cam demo will
let youdraw the arcs and use the Copy-Paste command to make the
multiple copies with one click. You can also then connect them all
together, and either generate the G-code directly with the CAM or
save the DXf file and use one of the DXf to G-code translators to
make the G-code.

There is not a "standard" G-code to repeat an arc, but some controls
support subroutines that can be used to repeat patterns, make a
slight adjustment, repeat the pattern again, etc.

Some machines have what is called a conversational control. This
type of control may be able to directly process the commands to cut
what you want. So far none of the hobby class machines have this
capability, but Ron Ginger has done some investigation and
development. You might want to search the archives if you want more
info about what he has been working on.

> If not, I think it would be possible to redo the same arc 6 times,

but

> decrease the tool radius compensation by .003 to get the desired

result. Is

> there any way to do this with sub-programs and counters rather than

writing

> the same code 36 times?
>

Yes, however you must understand that the arcs will have a different
radius if you do this with cutter compensation values. You will get
6 identical arcs if you use subroutines and execute the same G-code,
with just a translation, rather than a change in the cutter comp
radius/diameter offset.

> Can I program using start angle, end angle, radius and center point

(0,0)

> rather than end points?

Not with G-code.

> And last, but not least, is this the proper forum for these

questions, or

> is there another list I should belong to?

This is the place.

Best Regards,

Fred Smith
IMService We are THE source for low cost Cad-Cam

http://www.vectorcam.com/cced.html