Building Toothpick Bridges

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Building ToothpickBridges

• 6th Grade Project

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Materials

• Elmer's Glue
• 60 Toothpicks
• Wax Paper
• Project Board

3
Project Rules

• Each bridge must be at least 11 inches long and
  stand 2 inches above the ground.
• Each bridge must be EXACTLY 2 inches wide.
• You may only have a maximum of 15 toothpicks
  connecting the right and left sides.

4
Construction Steps

• Draw your plans on a piece of 8.5 x 14 inch
  paper.
• Make sure your plans are symmetrical and use
  triangles for strength. There should not be any
  rectangles in the sides.

5
Construction Steps

• Now find the point half way in between the
  beginning of your bridge and the middle point.
• Draw a line to the top of the paper from this
  point.
• Do the same thing on the other side of the middle
  Point.

6
Construction Steps

• Draw a horizontal line 2 above your bottom line.
• Now begin to draw your bridge using the points
  where these lines Intersect.

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2
0
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0
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0
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Construction Steps

• Place your drawing on a project board and cover
  with a piece of wax paper.
• Put a staple in each end of your drawing to hold
  in place on project board.
• Put a drop of glue half the size of a dime in an
  upper corner of your project board.

18
Construction Steps

• Begin dipping each end of A toothpick in the glue
  and lay on the bottom line of your plan.
• Dip the next toothpick in glue and lay beside the
  first with about one half inch of overlap.

19
Construction Steps

• Begin laying down the toothpicks for the top and
  bottom lines.
• Build in the diagonals for the sides.
• Build the abutments for the bottom.

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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
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Toothpick Overlap
Tips should overlap about ½ with glue between
them.
29
Construction Steps

• Complete one side, let dry over night, and remove
  from project board.
• Build second side the same way.

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Assembly Instructions

• Now add 2 x 2 abutements.

2
2
Abutement
31
Assembly Instructions

• Now stand the two sides up 2 apart.
• Connect the two sides with 5
• toothpicks across the top and 10 toothpicks along
  the road bed.
• Let this dry for two days