Mechbox Torque Load, the Last Piece of the Puzzle:

The equation for expected rate of fire as derived allows us to calculate an expected rate of fire given a specific mechbox torque load and gear ratio. This is powerful in that if we know what load our mechbox currently exerts on the motor, the equation allows us to predict what our rate of fire will be with any other gear ratio. But just how do we figure out what torque load our mechbox exerts? Predicting the exact torque load is difficult given the multitude of parts which effects the ease with which the mechbox cycles. Different pistons, piston heads, cylinders, springs, bearings, gears, shims, lubricant, etc could all easily effect the overall torque load which the motor sees, making prediction of the exact torque load purely from a parts listing nearly impossible. Does this fact render the previously derived formula useless? Not quite. The same formula can be reconfigured to solve for torque load given a known gear ratio and a known rate of fire:

Starting with:

ROF = ((27552/1407)*(1407-(mechbox torque load/gear ratio)))/gear ratio

We can solve for torque load and get:

mechbox torque load = (-(ROF*1407*gear ratio)/27552 + 1407)*gear ratio

This gives us the critically missing piece of the puzzle. With the mechbox torque load now calculable for a specific combination, we can predict expected ROF with the same combination when different gear ratios are used. Below is a sample plot showing predicted rates of fire for 3 different arbitrary loads and 4 available Prometheus gear ratios.



It's critical to note here that at high mechbox loads such as with a strong main spring (yellow line), the shape of the curve takes a down turn at lower gear ratios, exhibiting behavior opposite that of medium and low mechbox loads. The apex of the downturn signifies the point where using a lower ratio/higher speed gearset sacrifices too much torque multiplication and ceases to improve the rate of fire.