When physics are enabled, your pendulum will inevitably be affected by outside forces. So here’s what you can implement in your pendulum actor’s event graph:
You’d also wanna add a collision volume (box, sphere, etc.) to the actor like this:
As you can see, the collision volume slightly exceeds the bounds of the actor’s mesh on the sides but not on the top and the bottom. This way the player can stand on it without getting pushed.
And here’s the result:
Hope this helps! 