K'nex Process

There are many differences between using K’nex pieces to build a bridge and using steel to build a ‘real’ 20’ bridge.  K’nex pieces easily fit together and you have a lot of options when picking ‘gusset plates’.  However, all of the connecting pieces are 45 degree angles, and you are very limited to the types of triangles you build.  In real life, you can make any desired shape out of various materials and connecting pieces.  This is a disadvantage of using K’nex pieces. 

Something our group struggled with was figuring out how best to use the connecting pieces.  We found out early on that the grooved pieces can easily slip and slide apart from each other when enough pressure is exerted on them.  We were just hoping that the designs we had would uphold a significant amount of weight.  The other disadvantage of using K’nex pieces is that there is no way to ‘bolt’ or glue the pieces together as you can do on a real bridge.  The pieces just fit inside of each other and we have to hope that’s enough.  The steel bridge in real life has the potential to be more efficient. 

Last week in class we brought sketches of a bridge design and compared them all to see which one we thought would work best.  In the end, we came up with a new design all together.  We had decided to use as many short members as possible to increase the strength of the bridge.  However, this caused us to use a lot of connecting pieces which really hiked up the price.  We are going to test it in class this week and we predict that it will fail due to the gusset plates sliding apart.