In general, the profile of involute teeth by using a cylinder. The involute curve by using a pencil which attached to the end of a taut string and unwinds from a cylinder. It is imagined that an end point of the string is pulled taut in one direction, then project its trace onto a plane that rotates with the base circle of culinder. The mating of teeths can be understanded by imahingy two taut strings that unwind from cylinders seperately. A moving intersection points formed along the tangent line of both base circlers when the gear pair is rotating. This pair of involutes is conjuate becaouse all points of contact having the common normal and tangent to their base circles. The tangent line two base circle "line of contact" which passes through the line of centres establishes the pitch point P. This in turn sets the size of pitch diameters.

Speed and even the torque of the output gear, train value e is a most relevant data that we can find from the formula below:

e=P1/ P2 = N1*N2*N4/N2/N3*N5

NL= e x nF

Where

NL: speed of the last gear

NF: speed of the first gear

N : teeth number