BoBCad Question

Art Fenerty wrote:

> I gues the reason I asked, is that my flashcut customer seems to be using a
> canned cycle that used such things as
>
> M98 P1
>
> which seems to call a subroutine that is specified at the end of the G-Code
> file in the form.
>
> O1
> G00Z.05
> n10 G00X-1Y-3
> ...
> M99
>
> What exactly is this form, it doesn't conform to any thing else I've
> seen. EMC does support the usual G80-G89 canned cycle codes, but what is
> this M98P1 stuff, I suspect its a macro declaration. Can BobCad put out
> regulat Canned cycles??
>

Now I recognize what they are doing. O (letter) is a "search code". The old,
paper tape based CNC controls could search the tape for a line like O1234.
I never actually realized that this could be used as a subroutine. I did use
it to mark good manual restart points. You could type in the "search code"
you wanted to search for, and then hit a direction button, and it would go
find that block of code on the tape.

Yes, the M98 P1 tells it to go find the block starting with O1, and execute it.
So, it is being used as a macro (or subroutine) in this program.

The reason canned cycles are not used that much in the lower cost CAM
programs is that they are so non-standard. basically, for the Allen-Bradley
controls, the end user or machine builder would tell AB what they wanted the
canned cycle codes to do, and they would code that into the CNC executive.
So, the canned cycles are not even standard to a particular control. Some
later controls had programmable canned cycles, so they could be loaded
from a shop's library of canned cycles, or set for a selection of basic operations
at the beginning of a program.

BobCAD CAM CAN put out canned cycles, if you define them and associate
them with a tool. It has a bunch of stuff where you can write your own
G-code commands and store them in a custom function. I'm not too sure
how you get Bobcad to call up these functions when generating a toolpath
from a drawing, though.

Jon