Re: Postprocessor

Jerry,

Post processors are still very much needed. An example I know of is
with a 5 axis machining center owned by a customer. They're doing
high speed (hundreds of ipm's) contouring in non-ferrous material.
The work could be done with a conventional 3 axis mill/ball nose
cutter combination. Except by using a conventional ball nosed cutter
the cutter's peripheral speed is near zero when cutting on the very
tip which means the effective contouring speed has to very slow.
This doesn't allow for the needed high speed contouring, which means
under utilization of this $300K+ machining center.

The post processor comes in by taking the normal Gcode output and
modifying it so the machine's extra two axis movements on the head
will align the cutter with respect to the part's surface such that
the cutting is taking place near the major diameter of the ball nose
cutter rather than near the tip.

This gets to be fairly complicated stuff. Last I heard, the guys
were getting bids on having a custom post processor written, bids
were around $15K!! I should mention that they looked at and own
some of the latest and greatest in high end CAM software and nothing
quite does the job out of the box.

I expect with all the varieties of multi-axis machines coming on the
market the need for high end post processors will increase.

Doug

--- In CAD_CAM_EDM_DRO@y..., Jerry Kimberlin <kimberln@h...> wrote:
(snip)

> Thanks to Bob Campbell, Tim Goldstein, and Fred Smith for their
> comments on Post Processors. I'm glad that post processors are
> pretty much un-needed now that some advancements have been made
> in the past 20 years when I first heard about post processors.
> It really makes no sense to me to have a cascade of programs from
> drawing to motor driver.
>
(snip)