Final Reflection

         From the onset of the ME 250 course it became evident that the course's subject matter focused directly on engineering principles of design, manufacture, and test. From the very first lectures, I was explained how this procedure allows a team to begin at point A, where a problem or task is identified, and end up at point B, the final product. To get to the final product, however, a "bridge" must be constructed in order to cross over. This bridge, metaphorically speaking, is one which is constructed from a series of links, and this called the engineering design process. In this course, I learned how to build this bridge. 

         In regard to the design and manufacturing in this course, I learned that it is important to complete the design in its entirety before any manufacturing can begin. This seems like an obvious statement, but until this course, I didn't realize how crucial it really is. I am specifically referring to the mathematical analysis behind the torque calculations and extensive design of the physical machine in order to satisfy the parameters that our strategy encompassed. Before this course, I would have opted to manufacture the machine first and then attempt to choose a motor and gear ratio by testing a few combinations, thereof. Thankfully, the process was carried out contrary to my (amateur) instinct, where all the meticulous calculations were done beforehand, and because of this, no altercation of which motor and gear ratio we needed to use was performed. The implementation of CAD performed on Solidworks allowed us to agree and modify certain design aspects as well as double check that pieces align properly. As far as the manufacturing of the machine is concerned, I learned the importance of tolerances and how they impact the interaction between machine pieces after they are put together, i.e. the meshing of the gears, and clearance hole fits for screws, bearings, and shafts, but not so much the actual use of the Mill and Lathe due to some prior experience with the Baja team. Time management and teamwork was key to keep our progress moving at a constant pace as well as making this project very bearable, if not exciting . Although time management of our team proved not to be our strong point, we were still able to complete tasks on time, using each other to motivate such progress, as well as address any issues that arose. Our team worked together well, especially because certain strengths of team members accounted for weaknesses of others, and vice versa. All in all, I learned that teamwork and time management is absolutely vital for engineering projects such as this, as opposed to it being completed individually.

         As far as the course is concerned, I thought it was put together very constructively. I am thankful for the coursework in the beginning of the term which taught us background knowledge and theory behind the manufacturing process and engineering elements. The posted lecture slides were very useful throughout the term and contained all the necessary information, however, were not specific enough in what certain assignments asked for, especially when it came to torque calculations. The material was there, but it felt like certain elements had to have been "fished" for . Also, the Mill and Lathe availability was too low and our team was often scrutinized to reserve enough time in the shop. For next year, I would hope that the shop hours would be extended from the very beginning of the manufacturing process, as opposed to later, especially because ME 250, 350, and 450 must share the shop. This way, it would take away elements of stress on the teams especially if some unforeseeable problem arises. 

         I felt that my performance in the class was very adequate and that our machine benefited from my input. However, I certainly would like to become more experienced and independent at using Solidworks to CAD as I feel that is my weakness. Furthermore, I regret starting some of the milestone assignments so close to the deadline. Were it the contrary, there would have been less stress amongst our teammates and contributed to a smoother experience. It has been a pleasure working with my team and am very proud of our final product, even though we fell out of the competition in fourth seed. With the experience gained from this project, I am eager to continue to ME 350

Final Reflection

Over the course of the Fall 2011 term I have learned a great deal about engineering through all of my classes. However the most important skills I have picked up have come from ME 250 due to its applied nature. Specifically I learned a lot about design and manufacturing in the context of completing a mechanical engineering project. My background knowledge of the material presented in class was insubstantial so overall I made a lot of progress. Beginning with the design process, I learned that in order to create a successful design one has to begin at a broad, general level and progress through multiple steps focusing on progressively smaller details. Also, in order to properly go through the design process, knowledge of the manufacturing procedures used to create the final object must be at the forefront. In particular, ME 250 taught me about motors, gears, bearings, springs, and screws. In lab we learned how to use CAD through the program Solidworks and how to conduct simple engineering experiments. While I am far from an expert on these topics, I now know how these pieces fundamentally work. Overall the most beneficial aspect of this class was being able to apply the principles learned in lecture first hand and learn from experience. Especially physically learning to use the machines in the shop such as the mill and lathes helped to teach me about how things are actually made. Another essential aspect to ME 250 is the ability to work as a part of a team and manage time well. While our team was far from perfect as far as time management goes, we certainly learned from our mistakes and are more focused on accomplishing tasks well before the deadline in order to leave time to combat unexpected problems. As far as the teambuilding aspect, our team worked well together. This made learning about teamwork fairly easy. In general ME 250 is a very useful class that taught me about what it means to be an engineer.

While there are many positive features to this class there are also some ways it can be improved. One big potential improvement could be increased access to mills and lathes (especially mills) throughout the term. With three different classes sharing the machine shop, times had to be booked days in advance. Because of this, it was difficult for us to complete our machine on time. Also, while the amount of work required to complete the machine paid off in the end and greatly added to the value of the experience, it is not fair for a four credit class. Throughout the term my teammates and I spend an absurd amount of time in the lab and in the library completing assignments and making sure our machine turned out good. For future classes, the process should be accelerated early in the term so that the workload can be evenly spread out. The total workload would be more manageable this way if it cannot be made smaller.

As far as my personal performance in this class goes, I believe that there is not much room for improvement. One mistake that I made was dealing with the modeling for the required motor torque which severely set us back during the competition. The details of this mistake are chronicled in a previous blog post. Also, as a team we started late on some of the milestones and made some manufacturing errors that could have been easily prevented.

In final reflection, I am proud of the overall performance of our team and the final result of our machine. The staff did a great job teaching a mixture of hands-on and theoretical engineering that led us to build a competent robot. I am proud of receiving the fourth seed in the tournament despite the failure of our machine during the competition. I am looking forward to future classes of similar nature to build upon the foundation of ME 250.

Alex

Final Reflection

It has been a long semester with many hours of time put into the design and manufacturing of our machine, and now that it has finally come to an end, it is to reflect.

In class lectures, we received a thorough introduction to design and manufacturing processes.  First, we learned about the creative process behind coming up with an innovative design. We then learned how to visualize our design using hand drawings, like orthographic views, and using computer aided design programs like Solidworks.  In our preliminary designs, we were taught to use fundamental design principles, such as simplicity and constraint, to make the most efficient machine possible.  Then we came together as a team to decide on what designs we liked and which we could use for our course project.  This task always is difficult because every group member has their idea of the direction they want to go with the design, and the group has to narrow the ideas down to one comprehensive design that will work.  Once a design is agreed on, the manufacturing process begins.  Through training sessions and class lectures, we were given and introduction to machining processes and learned how to use the mill, lathe, laser-cutter, and water jet.  These processes proved to be extremely useful in the manufacturing of our machine, which was mostly made on the mill and water jet.  My favorite part was the solid plate across the back of our machine spelling out our team name, made on the water jet.  Safety was stressed while being taught how to use the machines, which is always important working with heavy equipment. 

During the last half of the class, we were very stressed for time.  If we knew that it would take as long as it did to master the machines and to get enough hours on them, we definitely would have started in the shop before we did.    I learned the importance of building in time for things to go wrong because, especially when working with new equipment, they usually do.

            This course on design and manufacturing has probably taught me more about practical engineering than I have learned anywhere else, which is why it has been one of my favorite courses.  With saying that, there might be a few things I would do to improve the course.  First, I would emphasize to the students that machining needs to be started earlier due to time constraints with getting on machines, especially the mill.  During the time leading up to the milestones, our group had a very had time getting mill time when it was needed.  This was partly due to that fact that we were all new to the machines.  It took a few sessions to get familiar with the equipment so that we could get pieces done quicker.  Also, during the introduction of the game, we were made to believe that some tasks on the table were more possible than they actually were.  For example, some slides were dedicated to calculations on pushing the tower, but many groups tried this strategy and none were successful.  The competition, for the majority of the games, came down to who could move balls from the front edge of the table to the goal.  This made the game less exciting than it could have been if other strategies were more reasonably achievable. 

            I believe that I, as well as my team, did relatively well overall in this course.    Our machine turned out to be manufactured well and was very sturdy.  One thing we could have done better would have been to get started well before the milestones were due so that mistakes could be fixed in the time period.  Also, we could have checked the validity of our calculations to make sure they were correct and that we could achieve our strategy realistically.  If we would have realized that pushing the tower would be so difficult, we could have incorporated a design more skilled at other tasks.  

            In conclusion, this class has been a valuable hands-on experience that has taught me a lot.   I never would have envisioned our team being able to build such a machine out of pieces of metal before this class; nonetheless, we did!  Had it not been for the significantly bigger hinge on the second table, our team could have been much more successful in the competition.  Thanks to the GSI’s for all their help on the project and all the hours they spent in the lab. It’s been fun!

 

Trevor

Reflection

            I doubt that I have learned in any class at Michigan so far as much as I have learned in ME 250 this semester. This has truly been a rewarding experience. At the beginning of the semester we were told that our project would be to design a machine that we would hook up to an RC control box and drive around to collect balls and deposit them in a hole. While it was exciting to think that by the end of the term, this would be something that we had accomplished, I had no idea how this would be something feasible for me to do. I had no idea how to build a machine within tolerances, so that it would fit together exactly as I saw it in my head. I did not know how I could possibly hope to become competent enough to engineer a remote controlled functional machine. Now at the end of all of this, I am positively proud of what I accomplished this semester, and of the machine that my team and I put together. Despite a poor showing in competition, I maintain that we would have had the best functioning robot of anyone and won the competition had we used wheels on the front instead of the ball caster.

            I learned this semester how to come up with an idea, and use the design process to bring this idea to life. I learned how to be an engineer. With the help of my teammates, I was able to design a machine to meet certain tasks and qualifications, and then make our design a reality in manufacturing it. It was a fun process seeing it all come together from the Lathe, Mill, and Waterjet. It was particularly enjoyable when we had to make difficult pieces like our aluminum coupling for the metal motors. While this was frustrating, there was an immense feeling of accomplishment when it ended up working, and came together as planned. The best feeling in the world was the first time we drove the machine, and everything just ran so smoothly. If there is one thing that I am utterly proud of in this project, it is the quality of our manufacturing. Everything worked exactly as it should (outside of the ball caster, but that is more of a design flaw). I felt that our design was the most efficient that we could have gone for, but it might have been fun to do something a little more creative and exciting with it. I really had a great time working with my teammates, and because of less enjoyable team experiences in the past, I really realized the value in a solid team. We all got along well, and I have a whole lot of respect for my partners. They are some of the most intelligent and hard working people I have ever met. Our success was largely due to our ability to work together while still doing our own separate things that we were most comfortable doing. There were very few issues that I had with our team, and without my teammates, I could not hope to be as proud of this project as I am.

            This course could be improved with more time in the machine shop and in the lab. We simply needed more time in the shop to comfortably manufacture our machine. We finished our machining on the last day without too much concern, but there literally had to be two of us in the lab and shop for at least 4 hours a day every day for us to do this. I was in the lab for more than 4 hours every day except the Saturday and Sunday for the last week and a half and Trevor was still there more than me, I think he might have lived in the shop during this project. We had to have that happen in order for us to complete the project, and I think that is a bit excessive. Also the 8:30 am was just tough, changing that would do wonders. I found it very difficult to get up in time to travel to North for lecture, and when I did, I found it even more difficult to stay awake during lecture. I eventually stopped going, and tried to teach everything to myself, which showed on my exam score. The best way that I could have improved my performance would have been by going to class or by making a better effort to understand and retain what I was learning when I tried to teach it to myself.

            In all though, I really did have a good time with this class, am very proud of our machine, and enjoyed working with my teammates. I had a good time developing relationships with the GSI’s during all the hours spent in the lab, and cannot thank them enough for their help. I also took great pleasure in getting the number 4 seed and rubbing it in Davor’s doubtful face, that was a great time. While stressful and I don’t miss it, it was a fun semester.    

Competition

        Unfortunately, today was a definite disappointment. We went in to the competition with high hopes, and fell far short of the success that we had been hoping for. While our machine was running better, perhaps, than it ever had, and I was more comfortable driving it than ever before, the table for arena 2 had a ridge in it that just proved to be impossible for the ball caster to clear. Regardless of the effort that we took to go at the ridge perfectly perpendicular at our maximum speed. It was a fun day, but a definite let down. We had much higher hopes. While we were able to clear the ridge after time expired somehow, and had been in scoring position for the entirety of our run, we were not permitted to advance since we had not scored, despite being given a win. It was an unfortunate and premature exit for Team Awesom-O. I am confident that without that obnoxious ridge, we would have had a real shot at winning the entire competition.

Time Trial

        Today in lab was the time trial for seeding in the competition tomorrow and was full of ups and downs. Our first task was to attach the bead rails to our machine, which, as previously mentioned, was a selection between losing points for manufacturing or not being able to collect rubber balls. When speaking with Jean, she encouraged our group to do all that we could to get points from the balls, as this would be far more of a help to our function grade than the beads would hurt our manufacturing grade. We therefore went ahead with gluing the bead rails securely to the side rails. This proved to be a great success.

         One obstacle that we were faced with was the wiring of our motors. This was an extremely worrisome obstacle because we were only aware of it minutes before we were supposed to start our trial. When we initially hooked up the control box to our machine, we discovered that the back left wheel would not work. We also accidentally ripped out one of the connection wires to the 6 speed motor that works the front arm. We quickly re-soldered all of the connections that were giving us trouble, and after re-arranging the leads to the metal motor controlling the back left wheel, we were able to have everything functioning perfectly just as we had to run our trial.

        The trial itself went better than we could have expected and the machine was running the best that it ever had due to the care we had taken in securing all of our connections. I had been a bit nervous when first starting the drive, and knocked the first rubber ball and the ping pong ball off of the table. The ping pong ball was the only points that we knew we could for sure get. This meant that our success would depend entirely on the function of the beads, which we had not been able to test. Luckily they worked perfectly. We trapped a single rubber ball and took it back to the hole and scored with no problems at all, and we had a full 60 seconds left. We therefore went back down the table and collected the last rubber ball from our side of the table and one of the rubber balls from the other side of the table in one go and went back to the hole. Unfortunately, our machine got stuck on the ridge in the table and we could not get to the hole. We hit the ridge and took a hard left turn and rode the ridge all the way to the wall. For nearly 50 seconds I struggled to get the machine to force itself over the ridge but the ballcaster would just spin along the ridge instead of rolling over it. Then with 3 seconds left the ballcaster cleared and we dropped the two rubber balls into the left side of the hole right as time expired in an exciting finish that brought the crowd to their feet.

        The three rubber balls that we scored with were enough for us to win our section and secure us the number 4 seed for the competition tomorrow. Such success really made all the hours spent in the lab tirelessly working on our machine worth it. Now, we can go into tomorrow confident that we can make a real run at winning this competition.