RE: EHP External Hardware Proposal

> -----Original Message-----
> From: Matt Shaver [SMTP:mshaver@...]
> Sent: Wednesday, February 02, 2000 1:07 PM
> To: CAD_CAM_EDM_DRO@onelist.com
> Subject: Re: [CAD_CAM_EDM_DRO]EHP External Hardware Proposal
>
>
> I think that RS-274 needs to be updated to reflect the current "state of
> the
> art" by surveying all the additions and improvements that various control
> manufacturers have adopted, and resolve any conflicts (ie G2846.3 is used
> by
> two companies for different purposes).
>
> Matt
>
> P.S. It sure would simplify post processors!
>

I think the problem here comes from a gross lack of professional
conduct on the part of machine tool manufacturers. Before anybody takes
offense to this, let me explain.

We have standards in the computer industry, standards in the medical
industry, standards in automotive, aeronautic and marine industries. They
were developed from within and generally work well. The machine tool
industry does not share this cooperative atmosphere. The mood seems to be
one of distrust and short-sighted greed, as evidenced by the fact that more
than one well known manufacturer starts with a basic (and outdated) pc
motherboard design and has it rebuilt to a queer footprint. The result
allows them to charge $4500 plus $115/hr labor to replace what is really a
$65 board. At least one manufacturer pots their boards to prevent the
owners from repairing them. Another was requiring the owner to sign a
statement acknowledging that the manufacturer retained ownership of the
boards with the right to confiscate them (went belly up, of course).

EIA RS-274D provides guidelines for the language of CNC commonly
known as the G-codes. Most of the 100 preparatory (G word) commands are
unassigned, leaving the manufacturer to use as he wishes. In other
industries such unassigned coding would eventually become standardized
through market demands and industry cooperation. However, manufacturers of
CNC controls have not only consistently failed to agree on these issues,
they have blatantly disregarded the assignments established by RS-274D. For
example, one manufacturer uses G60/G64 for G8/G9. Another uses G43/G44 in
place of G41/G42. The list of conflicts I've seen could fill two pages. It
is one of the biggest obstacles to teaching CNC programming. It also
accounts for the fact that Mastercam ships with about 60 post processors.

Is cannibalization of RS-274D necessary? Consider the fact that one
modern CNC controller does just about the same thing as any other controller
and you wonder why they all do it so differently. Profit may again be the
answer. If you can run somebody's controller without training, they can't
charge you for that training.

The machine tool manufacturing industry is the lowest paying of
engineering fields in the US. Coincidence?

OK, maybe I ranted a little too much. Sorry.

Doug