Elizabeth Perez - Reflection

ME 250, being my first ME class, definitely began to put into perspective what it is to be an engineer; from hands-on experience with machining to teamwork and applied homework. Design and manufacturing mean a lot more to me now since I now know that a lot of work and effort are put into the final project.

Before this class I had no experience with machining so I was nervous about what the class expectations were going to be. After hearing about the mandatory shop training I was relieved, but after the training I didn't feel very reassured because I thought the training was very vague. It took me a while to get comfortable with machining but I enjoyed it in the end, particularly because it is commonly dominated by men. Manufacturing was easier to adjust to than was design being that I am left-brained and had trouble being creative and adjusting to SolidWorks.

I was glad to see that, as a team, we seemed to come together quite well besides being different individually. Our team put in a lot of time into this project, some of which, I think we can all agree, could have been spent more wisely. It took us some time to adapt to the project so we didn't figure out in time that it would have been better to split up the work. Time became precious as the project deadline approach and once we figured out that setting goals for the day helped us accomplish more, we began to use our time more wisely.

The course really opened up my eyes to all the resources that the Mechanical Engineering department has to offer its students. I had no clue that we had so many machines available and trained professionals to help us get through projects. Even with these resources I learned that setting yourself with a timeline or a to do list can help maximize the time spent on a project. Towards the end our team began to make full use of what we had learned along the way and we were able to get a lot more with our project.

Although the course was instructive and challenging, I think the experience could have been a little better. I believe the unfinished state of the rules for such a long time conflicted with the progress teams made. Being left brained I didn't feel too confident about making too much progress with our machine without having definite rules. The GSI's tried their best to answer questions related to the rules but at times things still remained unclear.

My performance could have been better had I made a slightly bigger effort instead of trying to give up on the class. The class soon began to consume much of my time and it frustrated me; had a kept a cool head I think I would have enjoyed it more. I also think I could have prepared myself a little more for the exam by studying more and having attended more lectures. With respect to our individual homework, I think I should have approached the GSI's more to clear up any doubts I could have had. Lastly, I believe I should have practiced with SolidWorks more than I did.

Mike James - Reflection

I learned a whole lot about the design process in ME250. We started by creating a strategy based on the rules and objectives of the game. We then determined how we were going to carry out our strategy. Our machine had to be designed in a way to accomplish specific tasks that matched our chosen strategy. We were able to narrow down our options through the use of Pugh charts, which was a new concept for me. Some requirements of our machine were determined experimentally, such as how to chose a gear ratio for pushing the flipper.

During lecture I learned many things about mechanical components. It was through this that we were able to decide what type of components would suit our machine and its specific tasks the best. Some of the things we learned about were gears, springs, linkages, pulleys, wheels, bearings, shafts, couplings and motors.

We created a model of our machine in CAD. This was entirely new to me. I really appreciated all that SolidWorks had to offer. We could see exactly what our machine would look like before making it. It was also neat to see the parts move together. It was very helpful to be able to easily make drawings for the machine shop from the CAD drawings.

In the machine shop, I learned how to properly end mill and use the lathe. I experienced a laser cutter and water jet for the first time. I also gained a deeper understanding of the importance of feed rates and tool speeds.

When our group began designing our machine, it became apparent that we all had differing skill sets. It was important that we took advantage of these differences. Some of our best and most efficient work came when we were all doing different things to accomplish one goal. One person would suggest an idea, while another did quick calculations and another put it into CAD for us all to see. I was able to learn CAD from my group and in return I taught them what I could about machining.

Time management is was a huge factor of this entire experience. That’s not to say that we were always the most efficient in our use of time. We found it was most useful to plan a time and list of goals for our next meeting. We could then immediately get to work when the time came. Sometimes, however, we did not plan so well. If there was a two-person job to be accomplished and all four of us were present, then it was a wasteful for the two people with nothing to do.

If I was to go through this entire experience again, I would put most of my efforts into improving our use of time. There were too many nights spent on the computer when we just sat around, discussing possibilities without really making any progress. I would try to make better plans and drawings before going into the shop to be more efficient. Some of our problems arose from engineering/designing while in the shop. I realize this is not good practice, but we faced a time crunch and a crisis that had to be solved.

There were a few things about this class to could be improved upon. I found it difficult to always know what had to be done next and by what time. Although all the information was available, I didn’t always know where to look for it. This was a problem when I realized at the last minute that I had an assignment to do. This could be a problem of my own, but perhaps the information could be organized a bit better. Our group found it extremely difficult to get mill time in the shop, and we were often forced to work in the autolab instead. While this was a good place to work, it was inconvenient at times. When we were finishing our machine and aligning its components, we tested it on one of the arenas. We then participated in the seeding round on another arena. This arena was slightly different and resulted in a misalignment on our machine. Because of this, we were unable to score at all. I was very frustrated to say the least. I had expected the arenas to be consistent. It was only a small difference, but it was enough to greatly affect our performance.

Personal Reflection: Juan Luciano

This class has taught me a lot not only about the design and manufacturing process, but also about teamwork and dedication. Being new to the world of mechanical engineering, I didn’t know what to expect from the design and manufacturing process, or how realistically we could replicate it in class format. I think this class really does give us a crash course of sorts in the design and manufacturing process. I now feel comfortable enough with the thought process that goes into the design of a product (as well as the technical aspects, like the use of Solidworks and the necessary tolerances and specifications) to utilize them at the next level of classwork, as well as in any jobs I may have in the future.

Along with everything I have learned about design and manufacturing, I have learned a good deal about time management and teamwork. At the beginning of the semester, I would have never thought time would be an issue. The exam is in mid November and we don’t have to go to class after that? It seemed too good to be true. I never knew how long it took to mill even the simplest part, and how all the setup time really seems to add up. I also found out how difficult it can be to schedule machining hours between four busy college students. During the last few weeks, this class became almost a full time job. I would find myself constantly having to make sacrifices, whether that be sleep or food or homework for other classes. I learned a lot about group work, too. I learned that it doesn’t take four people to mill a part, and that our time was often better spent separately than as a group. I learned to trust others more than I have in any group project before, and know that if one of group members was trusted with a task they would complete it. I also learned a lot about brainstorming as a team, and coming to agreements with team members even when we see things differently.

In regards to the manufacturing process, I also learned a lot about working in a shop. I learned about the importance of asking questions, and the consequences that you can face if you don’t. I learned that the setup is always the most important part. In Bob’s words, “you could train a monkey to use a mill.” This experience will definitely help me in the future in terms of realizing the feasibility of my projects, not only to avoid getting in over my head when I’m doing the machining, but to help make things easier on the shop workers in future jobs.

Overall, this class has been a crash course in all things design and manufacturing. In the end, though my grades have suffered, I have learned a good deal about what it means to be a mechanical engineer, and I look forward to putting that knowledge to good use sometime soon. Thanks for a good semester, everybody.

Carl Fuda Self Reflection

Throughout my time in ME 250 this semester, I learned a lot in regards to design, manufacturing, teamwork, time management, communication skills, and work ethic. I have come to respect the design process much more than before I took the class, and I undoubtedly have a newfound appreciation for products I use everyday and the designed objects that surround us every day.

I had no previous training in design or manufacturing before this class; needless to say, I learned a copious amount of information. The first and most important lesson I learned was that left-brained people like myself can have a very creative side; the creative process of left-brained humans is simply different from right-brained individuals. I then took this new information and enthusiastically took on the design process that we learned about in lecture. The “funneling” process of taking general strategies and molding them into concepts and modules through quantitative and qualitative analysis was an interesting topic and very useful throughout our project. The next step of taking an idea and bringing it into the real world was also unfamiliar grounds to me, and the learning process, while often intense, was very fulfilling. Using and learning SolidWorks software was and will continue to be very useful for me. Our team put many hours into our design; still, the most work undoubtedly was bringing our solid model into the real world and making actual hardware. With the amazing resources in the Mechanical Engineering Department at the University of Michigan (facilities I did not even know we had before this class) and the help of some very smart people (Bob Coury) our team learned a remarkable amount of information about manufacturing processes such as milling and lathing. Material properties, how to thread a hole, how to make sure through holes are the appropriate size for a press fit, and how to achieve a certain tolerance on a dimension are just a few of many tasks I accomplished this semester.

While the design and manufacturing aspects of ME 250 definitely dominated the class and learning, I also learned much about how to make a team function properly, how to communicate clearly, and how to manage time most efficiently. Without a doubt, at the beginning of the semester our team was, in a word, inefficient. We threw around too many ideas without a certain task or goal in mind and without proper planning. As the semester went on, I learned how to keep an overarching task in my head, and how to make sure our conversations were headed in the right direction. Furthermore, using multiple modes of communication (cell phone, email, etc.) helped our team meet often and promptly if we needed to. Additionally, while in the shop, setting a goal for ourselves forced us to make the most of our time. I do regret not splitting up tasks between the team more (we often spent the whole period all on the same machine); however, we were often limited by the resources available to us in the shop.

My only complaint for ME 250 is that there were many communication breakdowns/unclear standards. For example, I had no idea how the homework would be graded early on. If I did, I feel like I could have performed better. Furthermore, I often times found myself asking a GSI a question about the rules and hearing an unclear response for the simple reason that they did not know. It felt as though the staff did not do an efficient job of outlining competition rules and class standards.

BOM

Final Documentation

Yesterday was the final Slotbots II competition. Unfortunately, we lost in the first round (due to a controversial ruling!). Regardless, we had a lot of fun and were very pleased with our final machine depicted above.

The machine consists of three modules: the waterjet aluminum base plate, the front wedge arm, and the back scoring arm. The front and back arms were manufactured in a very similar process. The outer arms of these two modules were taken from the kit and milled to specific dimensions. The inner arms are made out of delrin bought from McMaster. The mounting of the planetary gearbox on the back of the outer arms (see pictures) was exactly the same for the front and back arms. The only differences in the two arms are the wedges located at the bottom of each. The front arm has a large waterjet aluminum wedge for securing the flipper, while the back arm has a wedge shape milled into the inner delrin arm for pushing ping pong balls. We used the 6-speed gearbox to rotate the back arm.

A few disappointments with our machine were how slowly our front arm took to make it to the flipper, and the lack of precision we had in rotating the back arm. However, overall we were pleased with the simplicity and clean look of our machine, and functionally it accomplished everything that we had desired.

Video