Mechanical Computer

IMPORTANT! FREEZE AND UNFREEZE UNTIL ALL RED GEARS ARE SPINNING! This might take a number of attempts. This is a differential analyzer, a type of mechanical analog computer for solving differential equations. This one solves the differential equation Ydotdot=-Y. One solution to this equation is Y=sin(t) and Ydot=cos(t). This should trace a circle if plotted with Ydot on the horizontal axis and Y on the vertical axis. The current values of Y and Ydot are displayed with the red sphere on the output table, so if you move the red sphere from the center of the output table with IJKL it will start tracing out a circle. HOW IT WORKS: Each of the large rusty steel spinning disks which turns a rusty sphere is what's called an integrator. Meaning, they integrate a mathematical function. The large spinning disks are connected to continuous servos which provide the time input. The input is the worm gear rod which moves the disk horizontally. And the output is the sphere. This is sort of like a CVT. If you input a rate of change, IE, a rotation rate, into the screw, the sphere's position on the disk changes. This also means the sphere's rotation rate changes. So it outputs a rotation rate depending on where it is. If you're confused, here's a great youtube video on how it works: https://youtu.be/s1i-dnAH9Y4?t=1856 The upper integrator integrates ydotdot(the second derivative of y with respect to time), outputting ydot(the first derivative of y with respect to time) This is integrated by the lower integrator to get y, which is connected to some orange gears to reverse the rotation and get -y, which is input into the upper integrator. Some of the most important parts of a differential analyser are the torque amplifiers. The torque output from an integrator is very low and is not enough to drive the input of another integrator or the output table. This is solved with an unusual device called a torque amplifier. A torque amplifier takes in a rotating shaft and outputs the same rotat