[nathan_hui]

I believe RobotIn3Days did something like that, but basically what the issue was that without a controller, the first wheel slowed down quite a bit first, so a second wheel was used to boost the muzzle velocity. Having the first wheel move slower would theoretically allow more overhead for a controller to work to improve the performance, but then again using the proper controller for a shooter wheel would improve the performance without the need for a second wheel.

Alternatively, without a controller, you could simply use the slower wheel to gradually speed up the wheel, so you might be able to shove more shots through.