Why the middle man?

[Diedesigner]

Hi all,

 

As a relatively inexperienced Mastercam Programmer, I have always wondered why Mastercam uses an NCI file; why the "middle man?" I import all of my graphics, and then program off of said graphics. What is the purpose of Mastercam generating an NCI file, and then generating g-code off of the NCI file? At the very base level, it seems that g-code should be associated with the graphics, not a "go between" file. Maybe I just don't properly understand the relationship between graphics and NCI files because of my background in SmartCam

 

Can anyone be gracious enough to share some insights and/or explanations as to why Mastercam uses NCI files, and the different ways one can use them?

 

Many thanks in advance.

 

Chris

[Allan Brown]

If all G-Code were the same format, that would make sense. Since it's not, they use an intermediate/neutral format (Mastercam's happy place, if you will) that get's converted to actual code by the post. I think you'll find that this is the absolute norm in the CAM world.

[Rekd™]

quote:

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I think you'll find that this is the absolute norm in the CAM world.

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+1, Dave.

 

Also, it's worth noting that most other CAM systems just don't make you aware of this fact, although it does happen.

 

Mastercam gives you all options. Very cool.

 

'Rekd teh elaborating

 

[ 06-18-2003, 02:14 PM: Message edited by: Rekd ]

[McRae]

quote:

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background in SmartCam

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Actually all the cutter location data was inside of the PM4 file but you just didn't get an explicit file for this.

 

Do a search on SmartCAM transitions here and you will find the issues that you will face as you develop both as a programmer and as a person.

[Nominal]

and now you have the option of not creating an external .nci file in MC. Speaking of nci files, has anyone ever created an external postprocessor that used the .nci files? Is there a reference somewhere of what the integer codes are and the parameters that follow them in the nci? Some of them are direct from APT 1006 etc but I doubt the file is exactly the same as apts cl file.

[Simtech]

You can get from your reseller a set of Mastercam Post Processor Guides, Volumes 1,2,3 in PDF format that will outline in very very much detail all that youneed to know about post programming.

 

Other "highend" CAM systems will generate CL files (cutter location files) and one standard format is APT (I think it's Advanced Programming Tool). The NCI and APT are both neutral formats for the programmed path.

 

Mastercam supplies multiple posts that will convert the NCI into proper G-code for the machine. High-End systems will tell you to buy some other product to generate the G-Code file (ICAM, IMS,...).

 

In SmartCAM, you need the PM4 file, the TMP file, the SMF file and the JOS file to get the code. In Mastercam, the MC9 file can be used with the post (PST and TXT files) to generate code.

 

I hope this helps a bit

 

Luc

[bryan314]

quote:

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Speaking of nci files, has anyone ever created an external postprocessor that used the .nci files?

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Nominal,

 

I'm sure there are several companies that do this but the only one I'm familiar with is PostHASTE over at www.postprocessor.com

 

Bryan

[TheePres]

Here at Tri-Tech, NC code for our 5-axis head is generated with outside post processor.

 

5-Axis

 

Post Processors

 

[ 06-19-2003, 12:49 PM: Message edited by: TheePres ]

[Surface]

quote:

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has anyone ever created an external postprocessor that used the .nci files?

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Isn't this done by NC_utilitys/post_processors/run_old. It will propmt for an NCI file. There was a time when the geometry was not connected to the NCI file and the only way to post anything was with the use of an external NCI.

[bryan314]

I believe the actual process is like the following.

 

When a toolpath is (re)generated a binary nci is created and stored internally in the mc9 file.

 

toolpath -----> bnci

 

When you 'post' a toolpath the bnci is then written to a text nci file.

 

bnci -----> nci

 

Now the post processor is really made up of 2 files. The program (dll) file which in nothing more than a chook and the pst text file. The pst file is usually what we refer to when we say, 'the post processor'. Mastercam reads the pst file and determines what post processor (dll) to use. MP.dll for mill, MPL.ll for lathe, and so on. It's question 91 in the pst file. The dll is then fed the pst file name, the nci name, and the output nc file name.

 

Then the magic gnomes inside the dll convert the nci to the properly formatted nc file. I say gnomes because I refuse to think of all the work that must have gone into programming the post processor dll.

 

nci -----> magic gnomes -----> nc

 

Now if you told mastercam 'not to generate' a nci file, it is deleted. If you also told MC to edit the resulting nc file it is also passed to your favorite nc editor where you can admire the work of the magic gnomes.

 

Now I'm sure someone from MC could give us a much more detail explanation than this, but other than myself I don't know anyone who would be interested in that. [source code with detailed explanations can be emailed to bryan (_at_) ivanxxxx (_dot_) com. ]

 

Bryan

 

Yep, magic gnomes, and I'm sticking to it.