Rigid Transform to Get Rotation About X-axis

Consider the figure below:

As you can see, the world reference frame and the quadcopter reference frame are coincident with one another. I am trying to connect the quadcopter to the world frame via a "Revolute Joint" block so that the quadcopter can only rotate freely about the x-axis. I know that I must transform the reference frame of the revolute joint with respect to the quadcopter body, but I am having difficulty getting this to work. I have tried to use a transformation that aligns the revolute joint Z-axis with the quadcopter X-axis, but that didn't work like I expected it to. Could someone explain this a little further? Any help would be much appreciated!

I have attached my model here for reference.

Answer 1

[Steve Miller]

You will need two rigid transforms to create frames for the base and follower sides of the Revolute Joint that have the desired orientation. You can see by looking at your image that the transforms need to rotate the existing frames by 90 degrees about the +y axis.

This image shows the connections and settings. Pay attention to the Base and Follower connections.

--Steve