[Vikesrock]

It is possible that the wheel is not wide enough to power the moon rocks well, but there are a number of other possibilities.

As Eric mentioned, this type of mechanism works the best when the wheels are already spinning and then the ball is fed into them.

Another potential issue is compression. Based on what teams have been reporting here and what my team has seen in very limited testing you want at least an 1" of compression at the narrowest point between the two wheels meaning they should be 8" apart at the most. You also don't want more than about 2" of compression so they should be at least 7" apart.

The last potential issue results from the drills. If the drills are not providing enough speed or torque or both your design may not work well. If the wheels are not spinning fast enough they will not transfer enough energy to the ball as it passes through. If the drills don't have enough torque, the wheels will slow down too much as the ball passes through and the wheels will then not transfer enough energy to the ball.