Surface perpendicularity - A beginners question

[Alexane]

Hello,
Please review the attached picture. The green surface must be perpendicular to the red surface, datum A, and to the blue surface which is datum B.
Datum A is perpendicular to datum B.
Which of the tolerance options is the correct one? Is it enough to ask for perpendicularity to one of the datums (Option 1 and 2) since the datums are perpendicular to each other?

Thank you,
Alex.

 

[drawoh]

Alexane,

Option #3 is the normal way to do it. Note how your datum feature[ ]A is your primary datum which is contacted at three points. Datum feature[ ]B is secondary, and contacted at two points.

--
JHG

 

[Alexane]

Hello drawoh, thank you for your answer.
While the part is conected to the secondary datum with two points, can't it still rotate about the axis connecting these points? If so, it will be perpendicular to datum A but not necessarily to datum B. What am I missing here?

 

[drawoh]

Alexane,

Your datum features[ ]A and[ ]B constrain five out of six degrees of freedom. Datum feature[ ]A controls X and two axes of rotation. Datum feature[ ]B controls Y and one axis of rotation. Your part is still able to move in[ ]Z.

--
JHG