Offline > Online

[khenry]

I wrote a program online and am trying to run it online. The probe angles are inconsistent. TA90B-90 offline is 90 degrees off online. When I changed it to TA90B-180, it was correct on the machine. Is there a machine parameter that's off? Any tips on troubleshooting when transferring programs offline to online? I'm new to this. Thanks.

[brian.freeman]

check your XYZ of the machine vs your model
F5 Part Machine

[Cumofo]

There's a powerful tool in the OPERATION/ GRAPHIC DISPLAY WINDOW/ TRANSFORM

You can move the CAD coordinate system to perfectly match the part's orientation to the CMM, and the available for measurement primary datums used. When sucessfully performed, you can then use CAD=PART. Pc-DMIS now more robustly displays graphic items properly, and queries the CAD data for nomial values and vectors quicker and does a lot of background feature set-up and analysis better too.

[khenry]

Thank you. This was helpful. Now I'm running into another problem. What is the best way to align the program to the part? I'm trying to do this by DCC alignment. So I'll open the offline program, delete the planes used for alignment, measure 3 planes on the part with the machine and realign. (This is DCC, idk if that matters.) When I realign it asks me if I want to change nominal dimensions. If I say "Yes" the other feature are off by >100mm. If I say "No", the features are off but by much less. What am I missing? Is there a good procedure to follow when bringing an offline program online? I don't want the operator to have to manually align every part. Thanks.

[derekvegeta]

I'm having difficulty understanding what exactly you want/mean by that.

If you mean making sure a program you make without cad lines up when you add cad after the fact (this is regardless of offline vs online): Use edit>Graphic Display Window> Cad Levels. From that menu, click on the Cad layer (0 if you have only one cad item) and then click transform. This will move your cad to relative to the XYZ of your program. If this is what you want, do NOT try to accomplish this in any alignment, manual or DCC.

Luckily for you, there's a lot of currently free online courses due to Hexagon's kind gesture during the current COVID-19 pandemic. The alignment one in particular you may find helpful. (though the others could still help)

[derekvegeta]

As far as modifying alignments go, you do NOT want to say YES given your situation where you want to replace an alignment feature. whenever you say YES to that question, PC DMIS will try and 'compensate' for the difference between theoreticals of the change for everything following the change. This will cascade changes throughout your program that will have you pulling your hair if you do not want PC DMIS to compensate that for you.

And even when you DO want it to compensate, some funky things can happen in my experience.

[Schrocknroll]

I don't follow your deleting and recreating the features. Could you post the code up to the DCC alignment? I don't even know where to begin to guess the problem.

[khenry]

Thanks, I'll take a look at the training. In the meantime, here is my process:
1. Create program offline with CAD model.
2. Open program online with machine.
3. Adjust CAD axis to match machine
4. Delete alignment written in offline program.
5. Turn on DCC at the beginning of program. Measure 3 planes on the physical part with the machine.
6. Add alignment. Select "No" when it asks to adjust nominal dimensions
7. Run the program. It finds those planes and align correctly. When it starts measuring it is off, probing in the air

[derekvegeta]

Why are you deleting your alignment? Also, the manual alignment is necessary for the first time you run the part: There are more advanced ways to bypass a manual alignment, but the simplest way is by marking/unmarking.

Your program broadly should go:
-Manual Alignment
-Start DCC command
-DCC alignment
-Measurements and dimensions

[BKulpa]

As stated by derekvegeta need to do a manual alignment of some sort to bring the machine coordinates to the part.
We typically do Plane, circle, point.
But a readpoint is an option as well.
Search the forum.

[Schlag]

1. You need to program your part as it would sit on the CMM. You need to orientate the CAD model to match that before you start offline programming. You also need to get to a training class. When you do step 5 on the program, none of your features will actually " overlay" the cad model anymore. Step 4. Why ? What are you trying to do that this is your work around ?