Materials

Parts List

Here's a list of the pieces of wood you need to get from the Hobby Shop.

Selecting the Best Pieces

Wood is very expensive, and you don’t want to buy more wood than you need.  You definitely don’t want to buy wood you can’t use.  In order to tell whether wood is good or bad, you simply lay it down on its side.  Bad pieces either have gaps between them or are bouncy. Once you’ve selected the ones you think are good, turn them 90 degrees and repeat the test in order to see if they are good in all directions.

Quick Weight Test

The chart below shows how much the bridge in our video weighs. On the far left hand side, you can see the names of each bridge member. In the middle, you can see how much each of the pieces of wood weigh. On the right hand side you can see how much the piece will weigh once it is part of the bridge. You can see the total weights on the row marked “Total”. All together, the material weighs 6.5 ounces.  Once the material becomes a bridge member, the total weight will be approximately 5.15 ounces. The maximum our bridge is allowed to weigh in this contest is 5.29 ounces, which is 150 grams. So we’re in pretty good shape.  However, if the bridge weighed much more, we’d have to get lighter pieces of wood. If the bridge weighed much less, we’d probably make the end posts heavier since they are supporting the most weight.