I chose to write this article because of a repeated problem I see
with CAM software vendors. They charge quite handsomely for
Post-Processors, especially 5-Axis or Multi-Axis Post-Processors.
However, more often than not, the VAR for a specific CAM software will
task the actual work to someone who is completely incompetent for the
task. The Post-processor is the most important part of the CAM system.
It takes all the work done in the CAM software and formats the output
for a given CNC Machine tool and CNC Control. I repeatedly come
across vendors who task post-processor development to someone who has
never even run a CNC! I recently had one where the person in question had never touched a CNC and his last position was a security guard. This is not to knock security guards but this person was clearly out of their element. I
recently dealt with this from a CAM VAR who believes someone with an
Associates Degree in Computer Science from a local Community College and
no CNC background is qualified to write a 5-Axis Post-Processor for a
CNC Control he has ZERO experience with. Talk about delusional! This is beyond unethical. It is borderline fraud. The history of
the CAM software is replete with stories of customers who were sold a
bill of goods by their VAR and left with essentially useless software. Whenever
anyone is purchasing a Post-Processor there are several questions one
should ask of your VAR to make sure that your aren't being ripped off. 1) Will someone within your organization actually be doing
the work or are you farming out the job to a sub-contractor to get the
job done? If you vendor is farming the job out, demand to
know who that sub-contractor is. You will become quite close to them as
there will ultimately be multiple iterations of a post before it can be
blessed and accepted. This use of sub-contractors is actually quite
common and should not be considered as something unethical. However,
disclosure and transparency is critical. Many smaller CAM VARs will take
this route because it's quicker to get the work done and satisfy the
customer. 2) Does the person developing the post-processor have any experience with the control system to be supported? If the answer is 'No', stop right here. Without the experience of actually knowing a CNC Control System, it is impossible to properly develop a post-processor. The
idea that someone with no experience with a SIEMENS 840D can write a
usable 5-Axis post-processor for that control is intellectually
offensive. If they can't explain to you what a CUT2DF statement is or a CUT3DC statement is then they are in over their head. 3) Does the person developing the post-processor have any CNC Programming and CNC Machining experience? Again, if the answer is 'No', stop right here. Without
the experience of actually knowing how a machine reacts in the real
world to a given CNC Control System, it is impossible to properly
develop a post-processor. If the post developer doesn't understand
FANUC AICC High Speed Mode or NANO Smoothing, it is foolish to believe
they can implement the functionality. If the post developer has never
operated a machine running a program that properly uses RTCP or G68.2
Tilted Work Plane functionality, it is foolish to believe they can write
a post that properly implements that functionality. I had a situation
where the CAM vendor in question actually caused a crash while trying to
operate the machine to test his post-processor. 4) How long will it take to develop the post-processor? This is a bit of a loaded question but an important one. An
ethical VAR will immediately tell the customer that question is
impossible to answer without knowing the specific Machine Tool, the
specific CNC Control, the options the customer will want supported and
what functions must be supported by the post-processor. 5) What do you need from me to assist you in developing the post-processor for our requirements? This
is a very important question and one that anyone in charge of procuring
a post-processor should have on their list. You should be ready to give
the CAM vendor as much data as possible. However, you, as the customer,
should NOT be responsible for getting any reference data regarding the
CNC Control System. CAM software companies are in the business of
developing software to support CNC controls. That should ALWAYS be the
responsibility of the CAM software VAR and vendor. The Applications
Department of the Machine Tool Company or Distributor should be the
first resource for the CAM software vendor. If your CAM software VAR obfuscates or in any way displays a
reluctance to answer these questions honestly, find another CAM software
vendor. Any equivocation is just an excuse. There are some very good CAM VARs out there with excellent post-processor developers. If you use Mastercam, consider Dave Thomson at Postability, James Wakeford at Barefoot CNC or Colin Gilchrist at eApprentice. Colin recently published an article on post-processors that every CAM system vendor and CNC Programmer should pay attention to. If
you use other CAM systems, reach out to other customers to find one
that you will be comfortable with. Don't assume that because you use a
well known CAM system, you will not get scammed. Conversely, don't
discount CAM systems that are newer to the US market. Bill Genc and his crew at TopSolid are top notch. (AlphaCAM users can feel free to contact me directly) You may also want to consider 3rd-Party companies like IMS Software,ICAM Technologies or Spring Technologies. All three offer custom post-processors as well as machine simulation that run directly from your NC code. Doing your homework up front and asking the right questions of your
CAM VAR will protect you from getting ripped off and given a expensive
but useless post-processor. |
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CAM Software Vendors and Post-Processors
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