How to make a component stationary in ProE mechanism

[bluepgt]

I'm trying to create a mechanism to display the motion of it and I'm very new to mechanism. I have read a couple of tutorials but none of them were addressing my issue.
How do I know which part will rotate.
I added a motor than a shaft to it. Got the shaft to rotate now the next part would be a bearing, but when I hit run the bearing rotates but the shaft somehow becomes a ground.
Can anybody help me or point me in the right direction.

Thanks