Torque, RPM, and Chosen Gear:

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Before we chose the gears we wanted we first considered the speed/rpm we wanted the horizontal base to rotate at. We chose a value of 15 RPM. We thought this speed was slow enough to control easily but fast enough for the control system. However we wanted it to be slower, so we thought gears were a good option.

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We also estimated that the launcher in its entirety would weigh less than 30 lbs (13.6078 kg). So we based our motor torque off of that. Our first instinct was a gear train, get a small cheap geared down motor to 15 RPM. The chosen motor had a torque rating of 15 kg.cm. This was the motor we chose.

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So we had the torque and RPM of the motor, now we wanted to know what number of teeth would work well. We began by calculating different output torques and speeds off of different gear teeth ratios. This was our result:

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*Note: we had to convert the 15 kg.cm torque into units of Nm to make calculations easier.

Converting back to kg.cm we resulted with a torque of 49.9999 ~= 50 kg.cm, which is more than enough for our system.