Roller Chain Animation This animation shows the motion of a roller chain on both the driving and driven sprockets. In this case the chain has zero slack in either the top span or the bottom span. This condition requires much more mathematical accuracy than with slack. The program involves first setting the chain up so that if meshes on both of the sprockets and the leading end of all the links are engaged with the trailing end of the succeeding link. Second the chain and sprockets must be set in motion so that two setup conditions remain in effect. The difficult part of the motion is making the transition from the top and bottom spans to the sprockets. At first a simple integration the the x and y coordinates with respect to the motion along the chain trajectory was used but that turned out to have numerical accuracy problems where the chain radius eventually exceeded the sprocket radius. Because of that failure, it was decided, for the two sprockets, to set the chain rollers at the coordinates of the sprocket notches. This worked reasonably well except at the transition between the top or bottom spans and the sprockets. At these locations the chain link motion is not totally smooth but usually acceptable. The learner has access to the number of notches on the small and large sprocket, the link length, the total number of links, and the chain speed.
Small Pulley Radius
Large Pulley Radius
Total Number of Links
Link Length
Chain Speed
Single Step
This causes each press of the Start button to advance gear 1 by about 0.02 radians