How could least square be larger than minimum circumscribed

I'll get that data next weekend, appreciate the interest....i ran both BF and recomp, but only ran recomp once as I didn't want the brain damage of re_reading some of my old questions on that...even though I just did, lol. I'll run both next time, the programmer uses BF and I feel we should be defaulting to recomp, he's very good, but I doubt he understands both without learning about them. also, he will often local align to a feature before really taking hit points therefore making bfrecomp less helpful imho. How do you check for form error on a sphere? When I see form I think GDT straightness, flatness, cylindricity, circularity.

I'll get that data next weekend, appreciate the interest....i ran both BF and recomp, but only ran recomp once as I didn't want the brain damage of re_reading some of my old questions on that...even though I just did, lol. I'll run both next time, the programmer uses BF and I feel we should be defaulting to recomp, he's very good, but I doubt he understands both without learning about them. also, he will often local align to a feature before really taking hit points therefore making bfrecomp less helpful imho. How do you check for form error on a sphere? When I see form I think GDT straightness, flatness, cylindricity, circularity.

If you select circularity for the sphere, it should give you the form error (sphericity), or you can choose profile of a surface but be aware that profile will include size as well as form deviations - unless you are using the geometric tolerance command and select the dynamic profile modifier.

Whenever you construct a new feature from previously measured hits, you should use BFRE. BF should only really be used when constructing new features from existing features that don't have surface data - like constructing a PCD through the centroids of a number of previously measured circles. The reason you should always use BFRE when the inputs are hits is that it will re-compensate based on the geometry being constructed rather than taking the original, pre-compensated hits. By re-compensating, you can effectively cancel out any cosine error the original hits may contain - for example if they were probed slightly off location.