I am using 2021.2 and have created a unilateral profile from a scan set on a CAD model. The points lie on the end of a part that is at a 75 degree angle and it shows out already but I haven't even ran the part?? Do I have to create it's own alignment? The profile is 2 (U) 0 to ABC
When you generate a scan from the CAD model, the hits will be populated from the CAD surface values. This means that normally, when you are working offline, prior to actually measuring the part, if you dimension the scan, it will have zero deviation. However, the way the U modifier works is that it has the effect of shifting the centre of the tolerance zone so that instead of it being centred on the CAD model, it is offset by a certain amount. In your case you have a tolerance of 2 with a U value of 0 which means that all of the tolerance zone is shifted into the material - the 0 means that you are not allowed any +material deviation. Because your scan hits are generated on the CAD surface, they are essentially sitting at the very upper limit of your tolerance zone which will give a measured value of 2.
When you generate a scan from the CAD model, the hits will be populated from the CAD surface values. This means that normally, when you are working offline, prior to actually measuring the part, if you dimension the scan, it will have zero deviation. However, the way the U modifier works is that it has the effect of shifting the centre of the tolerance zone so that instead of it being centred on the CAD model, it is offset by a certain amount. In your case you have a tolerance of 2 with a U value of 0 which means that all of the tolerance zone is shifted into the material - the 0 means that you are not allowed any +material deviation. Because your scan hits are generated on the CAD surface, they are essentially sitting at the very upper limit of your tolerance zone which will give a measured value of 2.
