Creative Crane Design Challenge

Sky Is The Limit, Inc.

The construction company is using a new, extremely dense alloy to build high-rise structures but does not have a crane that is capable of lifting the new beams and trusses into place. In order to make use of this revolutionary material they have asked that structural engineers with creative minds help them by designing a crane that is capable of lifting the extreme weight of the new beams and trusses. All they need is a scaled-down, fully functional prototype in order to move into production of the Creative Crane. With your creativity and problem solving abilities the Creative Crane can become a reality enabling the use of higher density alloys for building skyscrapers, bridges, and dams.

Specifications:

Design and build a lightweight crane that creatively lifts a variable load (P) from a structure a minimum vertical height (V) of 18 inches with a minimum horizontal (H) clearance distance of 9 inches from the edge of the tower or footprint of the crane. The crane structure may encroach on a 45° angle from the lifting point as shown in the diagram. The crane must lift the load a minimum of 6 inches vertically to qualify as a certified lift. The crane that lifts the greatest load and meets the design requirements showing proper application of the concepts introduced will be deemed the best design.

Criteria:

• You may do research to determine the design for your crane, but you must have an original design that you created.

• The crane has to be able to lift loads of increasing weight to a minimum height of 6 inches in order to be considered a successful lift.

• In order for the lift to be considered successful the crane must remain intact and standing upright while lifting the load.

• The load needs to be lifted and set back down for the lift to be counted as a maximum lifted weight.

• An exceptional crane should incorporate efficient use of materials (Efficiency = Maximum weight lifted / Weight of the crane) and craftsmanship.

• The structure of the crane must support the weight of the load and counterweight. You may not attach or fasten the crane structure to the test table, floor, or ceiling.

Competition Kit Materials

• Gearbox Motor Kit (Contains one electric motor: 1.5-4.5V, .20A, 11,000 RPM, 15.2g/cm.)

• One Creative Crane Motor Pulley (No modifications may be made to this pulley.)

• Four Pulley Guide Set (Used for directing the lifting cable from the motor to block & tackle system.)

• Two Quadruple Pulleys (Block & Tackle system used for mechanical advantage during lifting.)

Building Materials

• String (Twine) as supplied. (String shall be used for the lifting cable (25 ft.). For substitution as tension members of the crane, the amount of length that may be used is unlimited.)

• Balsa Wood (Maximum size and length shall be 1/8” x 1/8” x 36’-0”)

• 5 point score deduction for any alteration, coating with glue, lamination of two or more pieces together, splitting in half or any modification of any kind is not permitted to the wood. No other wood is allowed.

• 5 point score deduction for every 3'-0" additional piece of balsa wood above the total allotted length.

• Glue Type (No restrictions: i.e., hot glue, wood glue)

• Pins & Nails (Required for pulley guide set axles only.)

• Official Power Supply (0-30V DC, 3A)

Rules

1. No modifications can be made to the electrical components.
2. You may only use the materials provided in the competition kit (Motor & gearbox & pulleys).
3. Standard metal washers shall be used for the weights and counterweights.
4. Both the weights and counterweights must be suspended from the crane.
5. Instructor will provide all construction materials (nails, bolts, glue, and etc.).
6. A container shall be designed to hold washers for weight and counterweight, there are no restrictions except the container may not be structural and cannot rest on the ground.
7. You must mount the motor with the motor-mount gearbox provided.
8. All materials are the property of Elizabethtown Area School District and cannot be modified in any way.
9. You will have access to a power supply for trial purposes during the construction process.
10. The kit that was loaned to you must be inventoried at the conclusion of the competition. The kit must be returned in perfect condition (Each missing part will constitute a point reduction).
11. Violation of any of the above specifications constitutes immediate disqualification, as does any violation of the “spirit of the competition”.