Week 8

The boat was worked on a little more to get everything just right.  The netting was adjusted to make the boat more secure and balance.  The second pro engineer drawing of the boat was started.  Testing for the lumber has yet to be completed but another ASTM was found that could provide enough information that we don't have to test it.  A program was created in Maple 15 that will allow users to select quantities and weights and find out how much cargo or water bottles this can handle.  This is not yet completed but will be in the week to come.

Figure 1: Maple 15 program

Week 7

The construction of the boat was completed.  In order to do this, the other pontoon of bottle needed to be created and the base constructed.  The first step was to collect more bottles.  This was done by visiting a view houses right before the recycling truck came.  This did not take long due to the fact that plastic bottle were abundant.
There were some changes made during the construction that differs from the original design.  The original design called for cardboard to cover the top.  We did not think this would provide enough support.  We attached a half inch thick piece of ply-wood instead of the cardboard.  Before adding any weight we noticed that it was too rigid and starting to crack from all the weight.  Two more two by fours were adding going across the base to provide spots to hold the weight of a person.  With this attachment the strength of the ply-wood was not needed.  We could have switched back to cardboard but left it on so we could provide more weight for testing.
The testing of the boat was held in a pool.  The first attempt we applied two people to the raft.  The raft held up but was very unbalanced.  This was due to the bottles collected in the middle of the pontoon causing the raft to act like a seesaw.  We solved this by applying rope around the middle of both pontoon forcing the bottles to travels the four edges.  This balanced the boat much better.  Another person was then adding to show that it can hold its goal of 450 pounds.  The three people totaled almost 500 pounds.  We concluded that any more weight added would cause the raft to become very unbalanced.

Figure 1: The boat with the added rope around the pontoon and 2"x4"s across the base.

Figure 2: Raft holding almost 500 pounds and staying afloat.

Week 6

This week, we tested how much weight the boat could hold. A 100 pound weight was placed on the boat, and then 25 pound cinderblocks were repeatedly added to the boat, to see how much it could hold. The boat supported the 100-pound weight and six 25-pound cinder blocks, meaning the boat currently holds 250 pounds. No additional weight was added because the pool was not clean and we did not want to risk sinking the boat. Also, ATSM standards were acquired from the engineering librarian. We hope to run the lumber and plastic tests this week.

Figure 1: Testing of the pontoon

Week 5

This week calculations were completed. We built the first model of the boat and construction proceeded as planned. The boat was built to match the original specifications. Three hundred and ninety eight water bottles were procured and split between the two sides of the boat.  The two by fours were nailed together, and the cardboard flooring was attached on top. However, the boat was not tested this week, due to time and weather concerns. We will test the boat this week to see if it can hold the 450 pounds it is required to.