MENG 371 Fall 2000
Test 2
1) For the mechanism shown
(θ3=90°=constant), a motor is placed on the
slotted link, giving a constant angular
velocity ω2. It is desired to find the angular
velocity and acceleration of link C, as well
as the first and second time derivatives of b.
a) (30) Set up the equations to solve for the
required variables
b) (10) Create a MATLAB script file to
calculate the velocities, assuming that the
position analysis has been done and all
known variables have been entered.
ID:_______________
θ4
d
c
θ1
θ2
a
θ3
b
2) It is desired to have a quick-return cam with a time ratio of 3:1. The cam should move
forward and back 100mm. Total cycle time is one second.
a) (28) How would you use Dynacam to design such a cam system? (Describe what you
would enter into Dynacam.)
b) (4) Do you expect to need eccentricity in the follower? Why or why not?
3) (7) For the SVAJ diagram shown,
what function was used for the rise?
What is the advantage of this
function compared to the other cam
functions?
4) For the following questions, answer
them in your own words and in
complete sentences.
a) (7) Why is the measured
acceleration in the cam larger than
the designed acceleration?
b) (7) Describe the types of motion
constraints for a cam.
c) (7) What is an instant center?