Carly in Mech Systems

  Finding Polynomial Functions  Polynomial functions are versatile types of functions that can be used for cam design. These types of functions can be used for either single or double-dwell.  The general form of polynomial functions are:  In this equation s is the follower displacement, x is the independent variable and the C_n values are the constant coefficients.  The polynomial functions are determined based on how many boundary conditions there are. These boundary conditions are specified on the SVAJ plots. An example of SVAJ plots is shown below.    The boundary conditions that are found are then substituted into the following equations to get the specified constant values to then get the polynomial equation. 

  Graphical Velocity Analysis Graphical velocity analysis allows for quick checks of problem to find out what is going on before checking analytically.  In this type of problem you are given a linkage along with w2 and theta 2. With that information you are expected to be able to find theta 3 and theta 4. On the linkage you draw on the velocity vectors perpendicular to each of the links. This allows you to obtain VA, VB and VBA.  You then draw the vectors VA with the correct direction and magnitude. Then you draw in VB and VBA with the correct directions and the intersection point is where the magnitudes are correctly proportioned.