CNC 101 was Re: what is POSTPROCESSOR? a fundamental question

Well my understanding of post processing , having wrote many, has to
do with the format your controller needs.
ie G3 X5.766 Y6.706 I0.210 J-1.566 F37.7
or G03 X5.766 Y5.756 R0.244 F34.4 , for circles. The useage of I
and J or R being important here. A post process does just that ,
generate the gcode, and in the flavor your machine can understand.

Frank







--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Marcus & Eva" <implmex@a...>
wrote:

> Hi Ballendo:
> I am puzzled by the comment you made (snipped below).
>
> > The post processor is what "decided" to use the wide overlapping
> > circles instead of the back and forth rows to cut the lawn. It

had to

> > consider the needs of BOTH the part geometry AND the machine
> > capabilities to create the necessary mowpath (toolpath).
> >
>
> My understanding was that the post processor merely translates the

toolpath

> information from the CAM output into G code, and that the operator

creates

> the inputs via dialogue boxes to set the cutting strategy.
> I further assumed, that the internal calculator within the CAM

program

> (ahead of the post processor) was what determined the actual places

that the

> tool was intended to go, and in what order.
> That certainly appears to be how Mastercam and Featuremill and Work

NC

> operate (these are the CAM programs with which I have the most

experience)

> Mastercam, for example, creates an intermediate file called an "NCI"

file

> containing all the position and tool parameter information that is

then

> translated to G code by whatever post I choose.
> I still have to choose to make parallel vs circular cuts, and I do

so by

> accessing dialogue boxes on the GUI in the CAM program (not in the

post)

> and selecting my preferences.
> Are there programs out there that do this differently?
> I always assumed that they were all essentially alike.
> Cheers
>
> Marcus