Press Release

Announcement of Project Progress

Math, Science and Technology Application


Contact: Jeremy Kuhn
Period 7/8
FOR IMMEDIATE RELEASE
March 14, 2008

Systems Engineering II: Rov Team Arm Design

Sandy Hook, NJ, March 14, 2008-

Jeremy Kuhn is a student at the Marine Academy of Science and Technology on Sandy Hook, NJ. He is in the Systems Engineering II class, period 7/8. For Jeremy’s senior project he is designing and constructing a robotic arm for the Mates competition at Buzzards Bay, Massachusetts. This project began approximately January 1st, 2007, when the decision to work on this team event was finalized. Since then much work has been accomplished which is leading up to the competition. Recent progress made on this project includes construction and testing.



Introduction

For the Senior Design Project Jeremy has designed and constructed a robotic arm. This will be mounted upon his teams Rov, which will compete in the MATES competition on April 26, 2008. This competition has taken place for many years and encourages students to learn about possible careers in the marine industry. This year’s regional competition will have 18 teams, where the winner will go on to San Diego to compete in nationals. So far the majority of construction has been completed, and testing has already begun. The final steps of construction cannot be completed until all team members are ready to do so, which should be before March 20th.

Research:

This project began with extensive research. Jeremy began by traveling to the 2007 competition to get an idea of what he would be doing. Over the 2007 summer he came up with four basic designs which would later become his alternate solutions. Two of these designs were powered by hydraulics and two were powered by electricity. After discussing his ideas with his mentor, Jeremy was able to come up with the final solution. This solution has a large, narrow design and is powered by hydraulics. The hydraulics frees the arm from the electrical restraints of the competition. The arm was constructed out of polycarbonate, a very strong plastic which is used in items such as safety glasses and bullet proof glass. The hydraulic components, syringes of varying sizes, were obtained from a local pharmacy. The rest of the components were available within the schools shop.

Construction:

Once the polycarbonate sheeting was delivered, construction started to go very smoothly. Jeremy began by cutting out the four 12” by 1” by ½” pieces for the arms, and the two 6” by 1” by ½” pieces for the mounting blocks. He was able to do this very easily on the band saw. Next Jeremy glued the arms together using epoxy and allowed them to sit. Both arms lined up very nicely showed no major errors. After the glue had dried he cut the ½” by 2” triangles off of the corners. Jeremy then had to sand these areas so that they lined up together when the arm is closed. Before he could begin assembly, Jeremy still had to drill the holes through the polycarbonate. This step can be seen in Figure 1 below.

Figure 1, Main arm being drilled.


Jeremy was not sure if this would go smoothly so he tested it on a scrap piece first. After it was apparent that drilling polycarbonate caused no problems, he continued to drill the rest of the pieces. To fit the arm and mounting blocks onto the bolt Jeremy had to file the holes to make them slightly larger. This allowed all the pieces to spin freely. He then cut a small strip of sheet metal and used it to securely mount the on board hydraulic syringe. Finally Jeremy cut a small piece of tubing and filled it with water so that he could test the arm.
At first construction was very simple as it only involved measuring and cutting materials. As the actual assembly of the arm took place more problems arose. With the help of the team many of these problems were overcome quite easily. The most difficult part, connecting the arm to the syringe, took multiple attempts. After cutting the brass connecting wires for the third time they finally fit into place. Jeremy also had trouble mounting the syringe to the polycarbonate. At first he used epoxy, seen in figure 2 below, but this broke off a few days later. To fix this he used sheet metal as a bracket which holds the syringe tightly in place.

Figure 2, hydraulic syringe being epoxied to mounting block.

Testing

While not all testing has been completed, major progress has been made. While mounting the arm onto the Rov frame Jeremy decided it would be beneficial to test the arm while there is plenty of time left. To do this he cut a short 3 foot section of tubing, the same that will be used in the tether. This was first attached to the onboard syringe and secured in place with the use of both epoxy, as a filler material, and a hot glue gun to ensure a seal. The tube was then filled with water, and 1/2oz of the syringe was filled. Extra care was taken to remove all of the air bubbles from the tube. The other end of the tube was stretched out and secured to the control station syringe. At first the arms movement was very stiff. A few simple adjustments of the bolt assemblies and this was fixed. The arm was extensively tested out of water in the hopes of finding faults that would only show after extended use. None were seen. The arm was then submerged in the test pools to test its performance underwater. The results were very encouraging as it seemed to work even better. The assembled arm and frame can be seen in Figure 3 below.

Figure 3, assembled Rov in test tank

There were multiple problems Jeremy had been expecting to occur. He was worried the arms would not close all the way, but taping the arms closed overnight stretched the brass wires enough to work correctly. Jeremy also feared that similar to the model, when the syringe would spin 90 degrees it would lock in place. Since he used a slightly different method of securing the wires this did not happen. The arm is now capable of working equally efficient no matter what position the syringe is in. A third problem was his worry that the arm would not close with enough force. After testing this does not seem to be a problem as the arm can hold about five pounds before the item slips. This will increase once the rubber grips are installed. The true limit on the weight the arm can hold will be determined by its effect on the stability of the frame. This cannot be tested until the entire Rov is complete.

Expectations

Although the arm is very near the point of completion, Jeremy still must work to make it meet his expectations. The arm, when completed must be able to hold about 3 pounds underwater and carry it to the surface. This must be done in a speedy fashion to score maximum points at the competition. He expects that my arm will be able to complete all the tasks without problem, although this must be tested to be certain. Jeremy’s hope is that the arm will function very smoothly at the competition and will not be the teams limiting factor, should there be one.




Mentor

Many of the major decisions Jeremy made were done with the help of his mentor. While not directly related to the field of hydraulics, my mentor, an electrician, was very helpful during construction. His personal shop was used to work on the more difficult pieces, while his connections to others in the field allowed him to find the answers to questions Jeremy had. The mentor is a close family friend and lives very near to Jeremy’s own home. This had made it convenient for him to share ideas with his mentor.


Conclusion

The Mates Rov project is a great learning experience that has taught Jeremy about teamwork and dedication. While designing the Rov Jeremy had to study the math and science related to the field of hydraulics and was able to gain a better understanding of their functions. As the competition nears, the amount of work completed as a team becomes apparent. Although it is too early to celebrate, Jeremy believes we have a good chance at winning the regional competition and moving on to the nationals. All testing so far has had nothing but positive results, and the arm is highly specialized to the contest tasks. The narrow design will prove useful in capturing the rock crabs, while the sturdy construction will make sure that minor bumps will not put the Rov out of commission. As a team they have high expectations of their designs and await the chance to prove ourselves in the upcoming competition.


For more details about the Rov team arm design on Sandy Hook, NJ, contact Jeremy Kuhn at jkuhn@mast.mcvsd.org, or visit http://www.se2rovarm.blogspot.com/.