WOOD TOWER DESIGNS

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WOOD TOWER DESIGNS

• Objective Students will be able to construct a
  tower out of wood in order to investigate the
  physics of structures.

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Towers are antennas.
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Towers are Buildings.
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Towers support power lines.
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Towers are support wind power.
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Towers hold clean water.
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Towers are vertical structures.
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Towers are shaped differently.
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TOWER REQUIREMENTS

• Tower teams of up to two members
• The structure must have the minimum dimensions of
  (a) height 14 inches
• The structure must weigh no more than 2 pounds.
• The structure may be of wood only.
• Any type of standard white glue may be used,
  nails, etc., are left to the discretion of the
  builder.

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TOWER REQUIREMENTS

• Before the test of the Tower, each team must
  promote their tower - give a sales pitch to the
  public (2 minutes time limit strictly enforced).
• The weights loading and testing apparatus will be
  provided.
• The weights may be added in any order.
• The structure must support the weight for five
  seconds.

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GRADING RUBRIC

• Towers must support a minimum of 69 pounds
• A Over 100
• B 99 90
• C 89 80
• D 79 70 Pounds
• E 69 pounds or less

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JUDGING

• The structure supporting its weight will be given
  points based on the grading rubric.
• The sales pitch will be worth 100 points, with
  the judges' decision to be based on features such
  as oral skills, knowledge of physical science,
  audience appeal, etc...

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GRADING RUBRIC

• Extended Constructed Response (1) 200 pts
• Brief Constructed Responses (3) 300 pts
• Sales Pitch (Oral Presentation) (1) 100 pts
• Warm Up Assignments (6) 600 pts
• Tower Building Participation (1) 100 pts
• Tower Test (1) 100 pts
• TOTAL 1400 Points

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WARM UP ASSIGNMENTS

• Create a daily plan of action
• This is a 4-5 sentence statement about what the
  group intends to do that day.
• Every group member must complete a daily plan of
  action that shows how they plan to contribute to
  the group.
• Each plan of action must include all actions and
  show a progression every day.

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BRIEF CONSTRUCTED RESPONSE 4

• Watch the video on www.youtube.com and comment on
  the strength of the tower presented. Write a
  statement about how the tower has succeeded (what
  principles of physics) to carry the designated
  weight.
• Http//www.youtube.com/watch?vCkCmtaPepww

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BRIEF CONSTRUCTED RESPONSE 2

• Write a four to five sentence statement about how
  your group plans to support the selected weight.
  Explain your design concepts (structural design)
  and building plans (construction methods) to
  complete your project.

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BRIEF CONSTRUCTED RESPONSE 3

• Compare your tower design to another group.
  Explain the similarities or differences in your
  design as compared to their design. Take into
  account construction, design, symmetry, joints,
  and shape.

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EXTENDED CONSTRUCTED RESPONSES 1

• You have been hired to complete a water tower for
  the city of Hyattsvilleburg, Maryland. The tower
  must carry three times its previous weight
  because of the increase in residents. Explain
  how your tower will support the weight of the
  increase in water. Use scientific principles in
  your explanation.

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BRIEF CONSTRUCTED RESPONSE 1

• Watch the video on www.youtube.com and comment on
  the strength of the tower presented. Write a
  statement about how the tower has succeeded (what
  principles of physics) to carry the designated
  weight.
• Http//www.youtube.com/watch?vCkCmtaPepww

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TOWER DESIGNS

• Engineering students frequently use wood to build
  model structures and then test them for
  weight-bearing capacities. The best wood tower
  designs incorporate some basic engineering
  principles.

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TOWER DESIGNS
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TOWER DESIGNS
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TOWER DESIGNS
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TOWER DESIGNS
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TOWER TIPS
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Structural Shapes

• The best wood tower designs use basic structural
  shapes, such as triangles, whose firmness allows
  them to support weight in a secure fashion.
  Squares and other polygons can also be used in
  tower designs, but require support if they are to
  bear weight without twisting and giving way.

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Joint Types

• A good wood tower design incorporates several
  types of joints to help increase its tensile
  strength. Butt joints are the simplest of joints
  as they simply consist of two members butted
  together and adhered with glue. Lap joints, on
  the other hand, use an overlapping method to join
  two pieces of wood or other material and offer
  greater stability.

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Symmetry

• Symmetry is essential to an excellent wood tower
  design. It is a good idea to form each one of the
  two main sides of a tower as they rest directly
  on top of one another.

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Adhesives

• The best wood tower designs require the sparing
  use of glue and other liquid adhesives. Many
  competitions require you to have your tower
  weighed, and excessive glue adds a considerable
  amount of additional mass to a tower. Do not use
  glue to fill gaps, and make sure all measurements
  are exact.

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Tensile Strength

• Pre-tests are important in determining good balsa
  wood tower designs. Strips differ in
  weight-bearing strengths, or tensile strengths,
  and it is important to group similar pieces
  together. During the final assembly of the tower,
  the strongest pieces will be most suitable for
  the longest parts of the structure, while weaker
  pieces better support shorter portions.

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INSTRUCTIONS

• Diagram the tower using the grid paper to give
  you scale one grid square represents 1 square
  inch, for example. Start with the base of your
  structure, making it wide to keep the center of
  gravity low. Design the exterior structure.
• Don't forget the rules of the competition, but
  feel free to brainstorm a little. When you have a
  design you like, make diagrams for several angles
  of the design--at least a front, side and
  three-quarters-rotation view.

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INSTRUCTIONS

• Use the diagram to figure out how forces, like
  gravity and competition weights, will push or
  pull on the tower, and imagine how that will
  stress the various parts of the tower. Add a
  system of supports to counteract this most
  buildings are built in layers with a series of
  triangular trusses that hold the structure
  together.

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INSTRUCTIONS

• Measure, mark and cut the base pieces for your
  structure. Miter them if you can, this will give
  more surface area to glue and make the structure
  hold together more cleanly. Don't mash the wood
  as you cut this will damage the fibers of the
  wood and make the structure weaker.

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INSTRUCTIONS

• Glue the pieces together. Hold them together
  until the glue is dry.
• Measure and cut the next layer of pieces. Glue
  them onto the base, and hold until dry. Repeat
  this process until you have built the tower. If
  you find a weakness while building, add a strut
  as necessary, but stick to your diagram as much
  as possible.

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INSTRUCTIONS

• Leave the tower to dry overnight. Test it with a
  light weight, to see if the glue is holding. If
  the structure has any damage, repair it and find
  ways to strengthen it.

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START PLANNING, DESIGNING, BUILDING.