Symmetry Plane in Base Alignment

[[Ra...]]

Hi - 

Alignment question. B1 & B2 are not coplaner surfaces. They are +.050 and -.050 on each side of zero according to the model. Would you measure both planes and then create (2) Theo planes with recall points and offset the actuals -.050 and +.050 and use symmetry plane for secondary alignment B? Wasnt sure if you could use symmetry plane with the actual measured planes and if that might skew things. It's just radially aligning after -A- is leveled. I know there is a Step Plane construction, but I've only used that if I have 3 stepped planes for my primary datum and offset them accordingly.

Thanks in advance. (ignore redundant post btw)

[[Ma...]]

Depending on norm you are working you can use Symmetry plane or symmetry of planes ( this is ordinary symmetry of features ).

Symmetry plane can give you MMB so use one depending of your drawing needs.