Concentricity Analysis on Cylinder Body HELP!!

[BrakeMaster77]

Hello All,

I have a debate occurring...we have a 0.7 Dia. (OD) Conc. callout relative to Datum A and a 0.6 Dia. (ID) Conc. callout relative to Datum A on the hub of a cylinder.

One group (Group A) is saying that it is better to measure multiple points along the radius of datum A (A1~A4) (both side of cylinder) to determine axis and the other group (Group B) is taking a few points on on each datum target and stacking the circles to create the axis.

My first thought is, the group taking multiple points around the radius of each datum target is doing it right. I think this due to having actual diametrically opposed points and more data on the datums. But then, I think, well if there is more data points captured could that potentially cause better reading on concentricity??

Note: Group A, more than not, measured conc. good and Group B usually has bad results...

Picture attached shows how Group A (Green Dots) and Group B (Blue Dots) are measuring on Datum A1~A4

 

[3DDave]

Can enough of the picture be shown to show what is being called for? It doesn't look like one would examine any radius for those targets but without showing the call out for the targets, it's not easy to tell.

 

[Burunduk]

Does the drawing specify interpretation per ASME Y14.5? If yes which year?

 

[TheTick]

Generic caution flag I throw out every time I see a concentricity callout...

Should this be done with runout instead of concentricity?

Most of the time, designers spec concentricity when they really mean runout. Most of the time, inspectors are measuring runout and not concentricity.