PCM problems?

[[Cl...]]

This may, or may not be PCM related. We have a family of parts (different sizes/same geometry). So we use PCM inside one "master" program to use for each size. A problem with a scanned surface just happened out of the blue. The individual
curves look fine. The reason I think it may be PCM related is that the model almost looks small?

When they are viewed after being recalled into a FFS for profile evaluation, they look terrible (pic attached). We requalified
the stylus, and no change. When the surface in question is being scanned we see nothing out of the ordinary. I did not
write this program. We believe that we've ruled out all potential problems other than PCM.

Poly.png

[[No...]]

Could you post your picture again? I think Zeiss updated the forum software and it seems some older attachments went down the drain.

[[No...]]

Difficult to say anything about possible PCM influence without knowing which parts of the program are parametrized and how.
Some questions that come to mind are:
- How does it handle the different CAD models (if at all)?
- How are the FFS nominal definitions extracted from the CAD models? Assuming they are different for each size. Are they pre-defined? I'm not aware of a PCM command that can do this.

I'm not sure I understand what you mean by "the model almost looks small"? Could you explain that in more detail?

[[Cl...]]

I'm not real familiar with all the program details, as I did not write it. I do know that the FFS you see is made up from several 2d imported curves. What I meant by; "the model almost looks small" was, some of the outer points (in attached pic) look like they are glancing off the part. As we watch these curves get scanned, we see no such thing. I know it's kind of vague, but that's all I've got.

[[Am...]]

It does kind of look like its importing a surface that doesn't match the part, how does it choose which curves to import? That would be what I'd look into first, is it possible its selecting the curves from a different sized part and that's why the FFS doesn't match. I kind of want to see what the surface looks like without the wire frame it seems like its scanning off the edges.

[[Cl...]]

Ok, thanks. I'll get back soon with a pic of this in a better view.