I began designing a clay disk launcher for when I go to a gun range and I want it to be something like this: I am having trouble sizing an electric motor since I don't have much exposure to E.Eng. The clay pigeon launcher is about 10cm by 10cm and I calculated my exit speed to be 20-35m/s if it's going in a projectile motion (min X distance = 30m & min Y distance = 10m) RPM = 20 m/s *(60s/min) * (rev / ∏(.1m)) = 3820 RPM RPM = 35 m/s *(60s/min) * (rev / ∏(.1m)) = 6685 RPM If I plan on using a 1:10 ratio of clay pigeon to driver I'd need a 1m dia. wheel going at 382-668.5RPM. This is where I run into issues.... 1) Is that possible with an electric motor? 2) How do I account for rolling friction? 3) How do I calculate the max RPM for the clay disk before it shatters?