EML 3262: Kinematics and Dynamics of Machinery
Number:
Test 2 Takehome:
Name:
Nov. 4, 2019
Problem 5: Take-home (10 pts)
Given: A student has designed a new package lifter as shown in the figure below (shown 1/20th actual size). The output force is applied at C, opposite to the lifting motion. The input force is applied at G, so that the output moves upward.
Find:
a) An expression for the rotational speed of link 3, ?3, in terms of speed that the hydraulic cylinder gets longer.
b) An expression for the rotational speed of link 2, ?2, in terms of ?3.
c) An expression for the velocity (magnitude and direction) of VC
d) An expression for the magnitude of VC
e) The MA (mechanical advantage) of system (speed of input divided by speed of output).
f) Is the lifter designed for strength (high MA) or speed (low MA)?
c:My Documentscleghorn_42046App_Acleg42046_app_a04.jpg
C
G
Problem 6: Position Analysis (10 points)
Given: The mechanism shown below is drawn to 1/20 scale (use cm for measurements).
Required:
1) Draw the graph of mechanism and identify its closed loops.
2) Draw vector loops and label each vector. Show each angle in the figure below.
3) Write the vector loop equations for the mechanism.
4) Use Solver in Excel to solve the equations when window has opened (final position) and closed (initial position). Determine the position of the hand crank in these positions. Are the slots drawn below long enough to allow the motion?
5) Extra credit: Check your solution graphically (CAD or by hand). (Submit your drawing to get credit)
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