Crane Stability & Rotational Overturning - Laboratory Worksheet

Name _____________________________________________	Date Performed _________________			

Team Partners ____________________________________

              ____________________________________

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Variables:
  • P = Load (number of pennies)
  • d = Actual Distance from
    the rotation point to the
    counter balance weight
  • D = Total Distance (1d, 2d or 3d)
  • M = Moment = P x D or P(cal.) x D
  • P(actual) = Actual Load Measured
  • P(calc.) = Calculated Load/Counterweight
  • Approx. Bridge Weight = P(calc.) - P(actual)
Note: If the Crane tips before adding a load then a counter weight must be used to balance the system.

Data Table 1:
Crane Arm - WeightXCounter Balance - Weight
DPMXDP(actual)P(calc.)
d
20
.X
d
..
d
40
.X
d
..
d
60
.X
d
..
2d
20
.X
d
..
2d
40
.X
d
..
2d
60
.X
d
..
3d
20
.X
d
..
3d
40
.X
d
..
3d
60
.X
d
..


Questions:

  1. Does it make a difference how high off the ground the counterweight is?
  2. Where is the best place on a crane to put a counterweight? Please be specific.
  3. Based on the results of this test, how will this concept influence your design? Please explain.