Load LinkageDesigner package
The benett mechanism should satisfy the following constraint between the angle of the joint axes and the length of the consecutive links
Define benett mechanism using the redundant equations (linkage1)
Animating the mechanism one can see that the solution of the constraint equation are correct in the whole range of the driving variable
Define benett mechanism not using the redundant equations (linkage2)
Animating the mechanism one can see that the solution of the constraint equation are correct only in certain range of the driving variable
Compare the constarint equations of linkage1 and linkage2