Catapult MA: Wheel & Axle, Lever, Crank?

[dbmorpher]

Our class was tasked with building a catapult.
We built ours based on DaVinci's
We have a wheel and axle MA of 8 and a lever MA of 0.108
We used a crank to stretch the cords, is this a machine that should be calculated in?

 

[berkeman]

Our class was tasked with building a catapult.
We built ours based on DaVinci's
We have a wheel and axle MA of 8 and a lever MA of 0.108
We used a crank to stretch the cords, is this a machine that should be calculated in?

Could you perhaps show us a sketch of your device, and be a bit more specific in the question that you are asking? Thanks.