I brought a CAD model in and checked some nominals to make sure the origin was where I wanted it. After doing my alignments, I like to take some test points just to make sure that everything is good. When I went to do this today, I noticed that the CAD nominals changed.
For example. The part I am working has two bosses that are 1.85 inches up from the origin, which is the bottom of a flange. I aligned and zeroed to the bosses and then moved the 1.85 back to the origin. Now when I check the CAD nominals, one boss checks 1.849 and the other is 1.88 or something like that, and the bottom of the flange which was "0" now ranges from 0 to .030.
something wrong with your alignment is my guess open a new program import the model check the nominals before any alignment. The model should be perfect should it not?
Already opened a different program to check nominals. Nominals are good. That's my point, how do they change? When I check the location of the bosses that I aligned to and they are at nominal locations ( because they are what I set up to ) how can the CAD nominals not be the same?
What do the IJKs's look like after the alignment, perfect or slightly off? I have found with arms that if you don't do two alignments (kind of a rough align and a final align using autofeatures) that the nominals, and vectors change ever so slightly. Take a look and let us know if the vectors after the alignment are showing what they should.