scans not the same

[[email protected]]

I am comparing 2 programs. Using the same part and probe. Both are Linear Close Scans. scan.jpg The scans are smooth on one report but rough on the other. Is there a setting changing the scans? I'm using a PROBEPH10, SP25M, SM25-1, SH25-1. PC-DMIS 2017 R2

[KIRBSTER269]

Well for one, your calling out one in Xact measure calling out certain Datums and you're not locking down all degrees of freedom, the other your calling out in legacy which is calling back to your alignment. and your tolerances are different, so they are both not the same

[[email protected]]

I screen grabbed the wrong thing. You are correct one is Xact measure the other is legacy but the tol are both +0 -.003. The FCF doesn't have all the degrees of freedom locked down but the Surface Profiles are under the same alignment in both programs. What effect would this have on the analysis views? If none what would cause this?

[KIRBSTER269]

not locking all 6 degrees allows the profile to Shift or Rotate for best fit, whatever is not lock down. But if your Datums don't match your alignment, then it's basing the profile from a different starting point, take a square block, maybe your "X" is controlled by the right side of the part, But your Datum is on the Left side, so if You are using Xact, DMIS will create another Trihedron based off of those datums. In your Editor left click on the your profile callout, now look at the CAD model is there another Trihedron?

[[email protected]]

It creates another Trihedron at the same location as the alignment Trihedron.

[KIRBSTER269]

ok, but since you only have 2 datums, even though your trihedron won't move, it is allowed to either rotate or shift, which you won't see, but can and will make a difference based off of the condition of the datums and feature by calculating worst case for best fit.

[[email protected]]

Boy was i having a bad day yesterday. The FCF for the racetracks is as shown below. All datum's used. Why would the scans be smooth on one and not smooth on the other? One is still Xact measure and the other is Legacy.


scan1.jpg

[JacobCheverie]

There are issues when it comes to Legacy computing MMB (modifier on a datum). In Xact, what does your datum shift look like? The MMB may be correctly optimizing your result, making it look better than the Legacy result.