Alignment method RPS or Best fit or Base alignment

[[Ma...]]

Hello everybody, 

 

Im having dificulties in defining an alignment. Basically, i have Datum C and Datum B, which are holes and then a Plane Datum A. 

I have to create an alignment using these two holes, 3 points on the plane. 

 I used RPS, point recall for the holes and blocked with 6 points but the results were very different after comparing with linear height column or other devices. 

 

Then I created second alignment with plane on Datum A, projection of C theoretically 3 mm below and created a straight 3d line to block. This gave me better results. 

 

Can you help me what is the best way? I have tried a lots of things and its not resulting. 

I can not share the drawings directly, so i created a something similar in paint 😊

Thanks in advance. 

 

 

 

 

[[Ma...]]

This can be used as regular alignment.

Primary: One plane A ( A1, A2, A3 )
Secondary: I would use C as a point ( circle or intersection of cylinder with near plane )

Origin would be from A and B.

Now there is a button "Special" where you can put those 3mm to obtain this. Those 3mm should be as basic dimension ( in a rectangle )