Advantages of External Code

[Slug Dawson]

Hello all, I'm looking for an explanation of the advantage of using external code in your program.

Alignments: I've heard others here talk about saving alignments as external alignments and then recalling them into the program and don't understand the advantages of doing this. Most of our programs start with a manual alignment or a single point aligned as XYZ-0.

Features: Is there any advantage to having feature sets as external code to use for similar parts?

Dimensioning: Any advantage to having the dimensioning as extrenal code and then recalling it for parts checked through different stages of production as stated in my example below?

The reason I'm asking is because we have a part that gets stamped & needs inspected at that point. Then it gets formed & needs inspected at that point. Lastly, it gets inserts put into it and it needs final layout as finished goods.

Would I set this up as 3 programs, one for each stage & just pull in the code for the necessary steps for each stage?

What is the advantage us using external code over copy/paste into another program?

Thanks for your input.

[Matthew D. Hoedeman]

ALIGNMENT:

1) IF NEEDED, you can change the alignment for whatever reason, and there IS NO WAY POSSIBLE for it to screw up any of your check features.

2) NO alignment needed in the check program. If you are using a dedicated holding fixture (automotive), you align it and you never have to worry about un-marking any alignment features in the check program. MARK-ALL, no manual, will NOT un-mark the DCC alignment that should be part of your alignment process.

3) You can have MANY programs, and in the build area, you MAY have many programs, all checking the same part, BUT YOU ONLY have to align once! Typical job for me: Part check routine, TRIM development routine, SPC only, FIXTURE R&R (STFU up, it's the FIXTURE, not the CMM), "special duty" programs (catch-all phrase). Total, this can come to HUNDREDS of features. You can do sets or some such crap, BUT, the bigger the program gets, the boggier it gets. The R&R (hopefully) only gets used once, the trim development will get used as many times as needed to get the trim correct, the CHECK ROUTINE gets used every time (and includes the SPC), SPC only gets run at the end for tool buy-off. This helps keep the program size down and all you ever have to do is MARK-ALL, NO MANUAL and the program runs, over and over and over.

Lots of good reason for external alignments (and a separate program to align). NOT a good way to do it if you have to align every part, but other than that, it's the ONLY way to fly!

(edit) IF your part sits on the SAME holding fixture for all 3 stages, then you could align the fixture ONCE, then run the STAGE-1 program or STAGE-2 or STAGE-3 program without having to align and you can go back and forth, over and over, until the machine is re-homed or the fixture moved without ever needed to mess with alignment features in teh check program.

[Chally72]

Just starting with external alignments, because everything else is much more involved….I use L shaped brackets on my CMM table. I have an external alignment that puts my origin at the corner of this bracket, on the plate. This means that I can corner parts in the L and always know where they are close enough to start the program with no readpoints or manual touches. Just give a generous prehit and retract, and start with first rough features, then a final alignment, all in DCC. I’ve eliminated the operator touching the joystick for 98% of my programs. No readpoints, no manual features, just GO. This opens up new possibilities like machine operators running their own part on an open CMM, because it requires no intricate knowledge of how to take hits, where to take them, how to setup the part, etc.

I have posts asking these exact questions from 2 years ago. Do a search under my username. I got a LOT of helpful info from a couple of guys here, and it really advanced what I was able to do on the CMM.

[Slug Dawson]

Thanks guys. Right now, I am the only monkey pushing buttons on the cmm. Most of our parts are set up using magnetic posts on the Rayco plate. We do have some fixtures but since they are such varied size & shape, having a common fixturing "corner point" would not be possible.

At another job, we had 5 rows front to back of plates with 8 nests each on them. We used these for multiple cavites of the same part. I had programmed into the code that the operator just had to type in which plate # they put the fixtures & the program would pull a startpoint to the plate & then go to each nested fixture to run the program with step & repeat loops. (Man, that seems like so many years ago).

Chally, my search for advantages of external code pulled very few useful results. I will do a search like you suggested and see what wonders I encounter!

Matt, I'm still trying to digest what you wrote. I think after 3 hours of sniffing brake cleaner & brake fluid last night, my brain is on strike.

Thanks again.

[DeWain Hodge]

Thanks guys. Right now, I am the only monkey pushing buttons on the cmm. Most of our parts are set up using magnetic posts on the Rayco plate. We do have some fixtures but since they are such varied size & shape, having a common fixturing "corner point" would not be possible.

At another job, we had 5 rows front to back of plates with 8 nests each on them. We used these for multiple cavites of the same part. I had programmed into the code that the operator just had to type in which plate # they put the fixtures & the program would pull a startpoint to the plate & then go to each nested fixture to run the program with step & repeat loops. (Man, that seems like so many years ago).

Chally, my search for advantages of external code pulled very few useful results. I will do a search like you suggested and see what wonders I encounter!

Matt, I'm still trying to digest what you wrote. I think after 3 hours of sniffing brake cleaner & brake fluid last night, my brain is on strike.

Thanks again.

I use a Rayco plate with all kinds of risers, but our plate is bolted to the CMM and is only removed for annual calibration. So I wrote a simple alignment program for the plate and recall it into every CMM program and give detailed instructions (in comment) on how to set up each part. Since I have done this I never use manual alignments.

[Slug Dawson]

I use a Rayco plate with all kinds of risers, but our plate is bolted to the CMM and is only removed for annual calibration. So I wrote a simple alignment program for the plate and recall it into every CMM program and give detailed instructions (in comment) on how to set up each part. Since I have done this I never use manual alignments.

That was the philosophy of previous programmers here at the company. The problem is, if you have more than one part set up on the machine, you may not be able to put the set up in the same spot. And the previous programmer ALWAYS put his parts in the center of the machine, 12" from the Y- limit of the stage. With a 3'x2' stage, that's an incredible waste of resources!

I've been tending towards a single touch point or circle to start all programs so there is the flexibility to set up more than one part on the cmm at a time. That way, you can work on more than one start-up during the day if adjustments need to be made.