Individual Reflection: Branton Dennis IV

ME 250 has been one of my favorite classes in college to this date. Following a robot through the entire design process and then being able to make it real was an incredible experience. I feel that the tasks given in the class were very real world based tasks that can be applied immediately.

The design stage started out as generic as any process possibly could, which I liked. Each team was to start out with a strategy that they thought would be most successful as scoring the most points or winning the competition. As first our strategy was to score one ball and block but after some thought we decided to switch to a more complicated and challenging strategy, to push the tower. Through this design process we learned many things but the most important of these things was to keep any design as simple as possible. The more simple you could make something means less work for you and your team as well as a higher reliability of the robot. I encourage teams in the future to thing about ways to make interchangeable parts in their robot because it makes the design process much more simplistic in the end. Because of the time we put into making parts easy to make and interchangeable, our team had very minable manufacturing time and was able to make a few extra parts in case of failure. We were able to make all of the parts on the stock then simply cut them off, “Mass Producing” as Mark called it. But even with all of this time spent planning our team still hit some road bumps. Our team purchased our tracks which meant that we had to design based upon pictures that we could see of the tracks. This led to some drastic redesign because our treads would simply not fit within the dimensions. With this I would encourage teams to order all necessary parts before cutting any critical parts because it is hard to design around estimates. I learned that leaving tolerances where you can is never a bad thing because it helped our team to have some “wiggle room” where we could afford it.

As time management goes for our team I think we did quite well, there were some late nights in there but we always stayed mostly on top of our work. I learned that if you planned to finish the assignments a day prior to when they were due at the earliest than you could always stay on top of the workload, that was until around MS7. Once that point hit it was a complete scramble for us and most teams. With shop time being short and the design starting to come together it really took a lot of time to make sure that things were perfect.

I did enjoy taking ME250 and participating in the competition but I would suggest one change. One of the changes I would make would be the viewing of years past robots. I believe that this took most of the creativity out of the competition. Many robots that were created had very similar designs to the years past.

I believe that I could have improved my performance in the course by spending more time in the early stages of the class preparing our final design so that when we were able to manufacture we could have spent more time in the shop while it was basically empty. 

Individual Reflection: Luc Hildebrand

Me 250 was unlike any other course I have taken here at the University of Michigan. The hands on experience we get in this class is extremely valuable. I learned about the how much time and effort is but into the design process and how to make CAD drawings. I also learned about the many different manufacturing processes; including how to use the mill, lathe, laser cutter, and water jet cutter to make different kinds of parts. I also learned how to create and properly dimension and tolerate engineering drawings.

In this class I found out that teamwork and communication is extremely important to successfully complete a project that takes as much time and effort as the one in this class. In order to complete the project on time everyone had to be on the same page, and had to be committed to spending multiple hours on the project almost every day. With such a short time constraint to finish the machine we really had to manage our time wisely to get all of our machine done in time.

Throughout the manufacturing/assembly process we came across a couple of obstacles that caused changes to be made. Once our machine was fully assembled we realized that the 100:1 gear ratio was not providing enough torque to push the tower, so we then switched to the 400:1 gear ratio. We were also using zip ties to keep our axle and the rubber tubing coupled together, but our motors ended up being too strong and were breaking the zip ties, so we then decided to use some copper wire  to couple the axles together.

I believe that this course could be improved in a couple of ways. The first way would be to give teams some more time for the manufacturing/assembly for the machine. It seemed like almost every team (including ours) barely had enough time to finish their machine, yet alone to make changes to features that did not work properly. Even just an extra week of manufacturing time would go a long way to help making our machines better, and would result in a much more competitive competition.

The second way would be to make the lectures shorter. The hour and half lectures, especially early in the morning, are very hard to pay attention too, no matter how interesting the material is. Although the lecture material is important, the lab and hands on learning are what make this class so great, and I’m sure that it would be possible to incorporate that material into labs. Any time that could be taken away from lecture and added to the labs would make this an even better class.

I think I could have done better in this class by paying better attention to detail. It seemed like every assignment I would lose a couple of points here or there just because I misread a question. Also for our machine attention to detail was very important to making the machine function properly and to look professional, which for the most part we did a good job on, but I feel that there was a few areas where we could have improved.

Overall I had a wonderful time this semester in ME 250 and I can’t wait to take the subsequent 350 and 450 courses. And lastly I wanted to thank everyone involved in making this such a wonderful class. It was definitely the best I have taken so far here at U of M.

-Luc Hildebrand

Individual Reflection: Adam Kloess

Individual Reflection

First, I would like to thank Professor Shih, Mike, Bob, Mark, and all the GSIs for a great, and especially fun (although somewhat stressful), semester.  Not only have I learned about the process of manufacturing something, but I have also learned how critical the steps are before the manufacturing process (including strategizing, narrowing down strategies, deciding on a concept, and designing).  For example, I never knew how important tolerances can be for certain components, such as bearings/bushings and holes for fasteners.  One trouble, that I’m sure was pretty common, was finding out that some parts don’t fit as expected.  Adding in this to the mix of everything made the work even more stressful.  Also, I have learned that designing and manufacturing a product take a lot more time than expected. 

Time management is a key factor when it comes to projects.  Even with lots of homework and exams from other classes, one must make time around all of this in order to stay on schedule (late nights will most likely be needed).  Scheduling with teammates can also be tough but you find out which days of the week work best, and you make the most of those days.  In addition, I have also learned that teamwork is crucial when you have a tight and busy schedule.

I believe there a few ways that this course could be improved.  First, it seemed that the workload for the first two thirds of the course was manageable (choosing a final strategy and designing out robot).  However, the workload for the last third of the course was too heavy.  When began to manufacture most of our parts, we still had many milestone assignments to complete (which I felt were also not spread out enough).  I believe the course will be improved if this workload was more spread out through the semester.  For example, I think if the design process started a week or maybe a couple weeks earlier, there would be less chaos in the machine shop.  In addition, I believe that some of the rules should be changed for the following years (that is, if the balltower competition is still around).  I understand that playing defense was allowed once a team scored.  However, I believe that the majority of the game should be spent trying to score.  This would truly test which team’s strategy was the best and it would make the game much more exciting!  Also, I believe that the higher valued balls should be more challenging to attain.  This could encourage more creativity and more differentiation between teams, and would also make the game more exciting.  As far as the machine shop, I believe we should have had some more practice with the machines.

In the course, there were a few aspects that I could have improved on.  I should have paid a little more attention during lectures.  Doing so would have helped me out on the exam and in the machine shop.  Also, I wouldn’t have had to go back and look at the lecture slides as much.

Overall, this course was by far my favorite.  There is nothing like getting a hands-on experience along with learning some pretty interesting material.  Congratulations to all the teams this semester.  I really enjoyed seeing all the hard work that was put into each robot!

- Adam Kloess

Roger's Reflection

ME 250 Reflection   -Roger Graves

                Let me just start out by saying this class has become my favorite class so far. I really have enjoyed all of the hands on work and the team atmosphere that the competition brings. It’s nice to actually go through all of the steps (even though there are probably too many) and have a final product that you are proud of. Throughout the term I have learned a lot about the whole design and manufacturing process that will become useful in the future.

                The main thing I have learned in this class is designing something with the mindset of manufacturer. I have never thought about all of the steps that go into making a design a reality before so having the appreciation of building something yourself gives you a new outlook when designing. Also we learned simplicity is key. During the competition we saw some very complicated machines that both worked and did not. We started the class with the mindset of creating a practical, simple, durable machine that would function exactly like we wanted it to. Also, we thought about if an actual company hired us to make them a robot that would look like a finished package not something with a tangle of wires connecting two robots for example. So designing a simple machine with the mindset of the manufacturer is extremely important in the success of any project.

                Another thing I have learned is if you are going to order parts make sure to do it early. There were a couple times where we had a deadline and we were still waiting on parts. This creates a couple problems. One you have absolutely no idea if the parts are going to make it on time. Another one is you do not know if they will operate exactly how you want so you need to leave time for alterations. For example, our machine is based off treads which, though awesome, were a bit thicker than we anticipated so we needed to drill additional holes in the base plate which took up time. In conclusion make sure to order accurate parts early.

                In order to improve the course, I suggest making it much less back heavy. The first couple months of the course consist of rewriting the strategy in different ways and drawing pictures. Although important should not take up the majority of the time. Literally all of the manufacturing was completed in less than 1/3 of the course. My recommendation is start manufacturing earlier to avoid the chaos of students in the shop and to ensure everyone has enough time to finish their machines. In addition to letting teams start earlier, I would recommend getting different gear boxes. I talked to multiple teams that had problems with their gear boxes or motors or even both. These tiny plastic things get ruined very quick and then it renders that vehicle that the team has worked extremely hard on completely useless.

                I could have improved my performance in the class by paying more attention in lectures. Having them early in the morning and sometimes a little slow made it very difficult to be involved.

                Overall I really enjoyed the course and the competition. Well done!

Thanks

               

               

Final Bill of Materials and Manufacturing Plan

Here's the link to our final bill of materials and manufacturing plan:
Step-by-step manufacturing plan and bill of materials

FInal Documentation

Starting out this competition with the lofty strategy of sliding the tower across the length of the table and placing it over our goal, we were setting ourselves up for a huge challenge right from the get go. Our initial ideas including a shallow box that would have treads mounted to the outside and would have a somewhat rounded ball catch in the middle. This would have had a horizontal base plate surrounded by 4 vertical 'walls' that would form the box. After more contemplation and discussion with our GSI, our direction significantly changed into having a single base plate with everything from the motor mount to the treads mounted directly on the base. This new direction gave us a significant increase in stability and accuracy, especially when mounting the treads due to crucial alignment of the axles.

The treads were another challenge that despite the difficulty we opted for because of the increase in durability and  traction that the heavy duty rubber would offer. These treads were driven initially by two 100:1 planetary gear boxes which in turn drove the sprocket/hub combinations in order to move the treads. Due to the inability to initially push the tower, we ended up changing the gearbox from the 100:1 to 400:1. With the new ratio and finally getting all of the tread components to fit in the base plate slots, we became the first and only team to successfully push the tower and reach a single round score of 175 g! 

In addition to our tanks ability to push the tower, we were able to collect loose balls on the table with the back catch and the treads forming a collection area. These balls could be scored by driving over the goal and letting them drop in. 

Overall we are very impressed with our machine and how it functioned before and during the competition. 

Thank You

Video!

Our video is finally finished! Please use the following link in order to watch it in 720p or 1080p for much better quality.
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http://www.youtube.com/watch?v=w199-ZJPdDA
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Or watch it here right on our blog.

Thanks for watching!

-Roger