The above figures shows a schematic of the mechanism. Input rotation is applied to the crank at point p1. The crank is connected directly via a shaft to gear 2 which has 6 teeth. Gear 2 meshes with gear 3 which has 12 teeth. This causes a gear ratio of 0.5 and a torque amplification (mechanical advantage) of 2. Gear 3 is directly connected to the output turntable via a shaft. The center of the train is located at point p2 on the turntable.
Due to the difference in teeth between the two gears, the output turntable only rotates 180 degrees with every full turn of the input crank (see figure bellow).
The figures bellow show the velocity and acceleration of point p1 as a function of input crank angle. We can assume that the user provides a constant input velocity of 10 RPM. Therefore, there is no tangential acceleration. The velocity of p1 is a constant 1.047 in./sec and acceleration is 1.097 in./sec^2.
The figure bellow shows a similar velocity and acceleration analysis of point p2 as a function of input crank angle. The velocity of p2 is a constant 1.440 in./sec and acceleration is 0.754 in./sec^2.
