What size DC motor do I need to make a soccer ball launcher? What torque rating? I will be using two 9" pneumatic tires that weigh 3.3 lbs each. I want to shot a ball from 25 to 90 mph.
Hello @scottlogan23,
Great project you have there 
I am a big soccer fan (although we call it football here 
)!
Check out this instructions:
They used 2 x MakeBlock 10000RPM 24V High-speed CNC Motor which you can buy here:
https://www.robotshop.com/en/makeblock-10000rpm-24v-high-speed-cnc-motor.html
Their machine looks awesome! I hope we can see your finished here soon!