Week 6-Greenwood

After using Knex over the past week designing and redesigning our bridge, my views have only slightly changed.  The main difference between my post last week and now is that I know that WPBD and Knex are two entirely different tools.  Since Knex requires us to think in 3D, WPBD really is only the first, most basic step in building a bridge.  

When building an actual bridge made of steel instead of Knex, there would be no loose "joints" where the Knex is having issues staying in a rut.  On a real bridge, the connectors are finals.  This just means that Knex allows the group to more accurately create a working bridge model, as opposed to just putting together something that is large, expensive, and ugly.  Hopefully our team can complete this task in the coming weeks, as the module draws to a close.

A2 Greenwood

The goal of this module is to create the most cost effective, useful bridge using Knex which spans a distance of two feet.  In order to accomplish this, many designs and prototypes had to be used.  In this case, we have just began the transition from WPBD to using Knex, and it is very difficult.  First of all, we are very limited by the cost and amount pieces/connectors we have to work with.  To overcome these obstacles, we have worked hard as a team to create designs which will work.  For this A2 design, I have drawn up a simple prototype which I believe could be cheap and strong.

Above is my rough sketches of my design.  Basically, it is a simple truss bridge which elevate to an even high sections of trusses at the top.  I believe this will add stability as well as good support for the weight apparatus.  The only issue now is the price.

Above is the projected price of my bridge.  Although I have not actually put together my idea, I am almost positive this will increase as I find mistakes in my design.

Week 5 Post- Greenwood

For the past five weeks we have been using West Point Bridge Designer as our groups main tool for creating prototype bridges.  Last week, we began using Knex to bring our ideas to life.  At first, using these tiny building pieces posed obstacles in our design process.  For example, it was difficult for us to bring our WPBD design into 3 dimensions.  Also, it was hard to pick which types of connectors and joints to use.  Overall, though, I believe that Knex are a useful tool for learning how to bring ideas to life; whether on a large scale or small.  

Therefore I believe that Knex and WPBD should not be compared, but used together.  This is because they compliment each other's usefulness.  Designing first in the bridge designer and then using Knex should be our process for the next few weeks, and I believe this will be the most efficient way of creating our bridge.

Jordan Banyas Week 5

Transitioning from WPBD to K-NEX is a lot different then I initially thought. The strategy when using WPBD is to keep a moving vehicle supported while it drives across where as the objective of the K-NEX bridge is to have it hold as much dead weight as possible. This week our group has come up with multiple designs we think will be successful. Our goal is to find the weaker areas of each design and improve upon them.

Transition

As we move from one design style to another, many new opportunities arise.  Unlike before, we are now able to be hands on and see each piece's strength's and weaknesses are.  In addition, we can now view our structure in a three dimensional space.  This allows us to make modifications inside and on top of the truss.  However, there are some drawbacks.  The biggest one is that now the revision process after failure is not as simple as WPBD.  The time and effort applied into forming a structure has to be applied over and over again after each failure.  It is tedious and frustration.  Yet, it a sense it is similar to before.  We still use the same geometric to distribute force and we definitely use what we learned from WPBD and apply it to our hands on approach.

A2-Carr

  The way I designed this bridge was quite standard but I believe it will still perform effectively.  It is the shape of a trapezoid to disperse the forces better. I chose to use triangles throughout the bridge to distribute the forces throughout the bridge and not have it deform before failure.  As I was advancing through my design process, I had to make many corrections to make sure that the connections of pieces was possible.  Also, I desired to not make the connections between the frames too detailed as it would add weight and cost.  I had a few drafts but settled with this one.  After this process, I learned that if one has to design a bridge, he or she needs to be patient and consider many factors.  Multiple drafts will only strengthen the outcome

Bill:
3.375" chord: 21- $31,500
5.00" chord: 14- $ 28,000
360 degree gusset plates: 18- $18,000
Total: $77,500

A2-Jordan Banyas

Our assignment for week five was to design our own bridge that can span two feet in length and at least four inches in width using K-NEX pieces. The goal of this design is to create the lowest Cost/Failure-Load ratio of the class. To do this, I tried to use as many triangles as possible in my design as triangles are the strongest geometric shape. along with making triangles, I made the angles under the most pressure forty-five degrees to evenly distribute the weight among the triangle. These were my final design images as well as a spread sheet of my designs total cost($140,500).

 Throughout the process of designing this bridge, I realized that just the acute triangles would not be long enough to cover the two feet span. because of this my design changed to add two right triangles on the end of my initial design. During the process I learned that the angle constraints are very limited when using basic K-NEX. There is not a whole lot of flexibility in the design process due to there only being a limited number of different pieces.