koobas.hobune.stream
Best Answer
The first effect of the ball passing through the upper plate attached to the stick might be because of the speed. Try to set the 'Collision Detection' to 'Continuous' or 'Continuous Dynamic' for your rigidbodies where their movement involves great speed as per what suits the best.
For more information: Rigidbody
There are also few suggestions at collision detection at high speed
If this does not solve your problem then you might want to use raycasting techniques but will require quite a lot of tweaks on your side: DontGoThroughThings
[4]: http://answers.unity3d.com/questions/587586/unity-high-speed-collision-detect.html
