This document provides instructions for a lab experiment on static and dynamic balancing. The objectives are to demonstrate static balancing techniques and draw force polygon diagrams. Students will use a balancing apparatus, weights, protractor, and Allen keys. They will adjust weight positions, observe the system's rotation, and draw force polygons to balance the system both statically and dynamically. Questions address why balancing is important and how static and dynamic balancing differ.

1. JJ508
ENGINEERING
LABORATORY 3
MECHANICS OF MACHINE
EXPERIMENT 3
STATIC AND DYNAMIC BALANCING

2. At the end of the lab session students should be able:
i. To demonstrate a simple balancing technique for
static balance.
ii. To draw a force polygon diagram.
Experiment Outcome

3. i. Static and dynamic balancing apparatus
ii. Set of weights
iii. Protractor
iv. Allen key set
Apparatus/Equipment

4. Apparatus/Equipment
LEGEND
A - Safety Acrylic Cover
B - Weight Piece
C - Circular Rod
D - Belt Pulley with Belt
E - Spring Damper
F - Fuse
G - ON/OFF Switch
H - Motor ON/OFF and Speed Controller
I - Digital Speed Display Meter

5.  Ensure the main switch (G) of the apparatus is switched OFF
when conducting the experiment.
 Remove the safety acrylic cover (A).
 Remove the belt from the pulley (D).
 Loosen the screw of the weight pieces (B) using the Allen key.
 Arrange all the weight pieces in a line where all the angles of the
weight pieces are identical to each other. Tighten the weight
pieces.
 Rotate the shaft to 90°. Release the weight pieces and make the
observation.
Procedures

6.  From the table provided, calculate the unbalanced moment
that makes the system unstable.
 Arrange the workpiece along the circular rod (C).
 Set the angle to 0° for the first mass and 60° for the second
mass. Arrange the other two masses to balance the system.
 Rotate the weight pieces and release it.
 Observe the system. If the system is balance, it should not
rotate after it is released.
 Draw the force polygon diagram for the system.
Procedures

7. Result/Data
Record the data obtained
Mass (kg) Radius (m) θ (°) Mr (kgm)
1
2
3
4
Total

8. i. Why does the balancing of forces must be perform
at any rotating machinery or shaft?
ii. Differentiate static and dynamic balance.
Discussion

9.  Give your comments based on the results obtained.
Conclusion and Recommendation