https://grabcad.com/library/2016-525-swartdogs-2
You can download our CAD from FRCDesigns to see what we did.
We had two tanks on the high pressure side and two on the low pressure side. We used two cylinders on the catapult. We varied the shot distance by changing the length of time the solenoids were on and by putting a delay start on one of the solenoids. This gave us a decent shot from a wide range of distances. It took a bit of calibrating to find the best settings for different distances. The competition bot didn't work quite as well as the practice bot because we never had time to really dial it in. We used the sames settings from the practice bot but even small changes in valves and the robot make a difference.