Adam Sachs' Individual Reflection

            I had a great experience in ME 250 and I learned a lot. Firstly I learned a lot about what the design process really is and the work that goes behind it. For example, before this class immediately after deciding the strategy I would have gone straight to the shop to start building the machine. This class taught me the value of having a well-planned design including working CAD models and engineering drawings. My internship this summer involves a lot of CAD modeling and testing so I have very happy to gain a lot of practice and experience with Solidworks. I also learned a lot about the specifics behind manufacturing. Before this class I had no knowledge of thread sizes, chamfering, nor the knowledge to use the mill and lathe machines. After help from Bob and Mark, I am very confident in my abilities on both machines as well as deciding on which thread sizes/drill bits to use.

           

            I also learned a lot about teamwork and time management in this course. Since I am usually the person to put off assignments until it is close to the due date, this course was a wake up call for me. I like how the course forced us to abide by a different timeline and thus, enabled us to be prepared come manufacturing time. I also learned more about how to work on a project like this as a team. At first it was pretty simple, the team would meet up one night a week and do the homework assignment. However once the project really started, that was when the teamwork was very important. We decided to work in twos in the lab because it was more than enough manpower and nobody would be working alone if they ran into a problem. We also found it easy to split up some of the assignments that didn’t necessarily require a full team effort such as the bill of materials and the CAD models. Of course, every person on the team had input as to what the model should be and what materials to use but more that one person was not required to actually do the work.

            One way I would improve this course would be to alter the lecture. The lectures were filled with some good information but I felt as if the bulk of lecture was unnecessary information that we never talked or used in the course. One way to do this would be to combine a couple lectures together and have the midterm early. This would give more time for teams to work on the projects together and eliminate unnecessary information.

            I could have improved my performance in the course by putting more effort into the planning and design of the vehicle. Unfortunately, we ran into a lot of problems in the manufacturing phase due to a lack of consideration for some obstacle such as planning for the battery box. If we also spent a little extra time planning, it could have been possible to improve our vehicle even more by making our arm retractable.

            Overall, I enjoyed this course very much. I found ME 250 to be a necessary step for all engineers to take in learning to master the design process. I am much looking forward to ME 350 in the fall because of this course. 

Jason Cassell's Individual Reflection

This semester in ME 250 has really been a great experience. Coming into this class I really did not know anything about the many machines that adorn the machine shop and which must be used in order to create a vehicle for our competition. I learned about the proper way to use the mill and the lathe. Bob Coury and Mark Stock were very eager to help when problems arose and when it was just confusing how to use one of the machines. I learned how to properly select drill sizes, how to use the drill chart, how to tap holes, as well as the entire design process. This class showed me just how important it is to have a good strategy. You could have a vehicle which executes your strategy perfectly, but if the strategy is flawed you will not win in the competition. Now I know why we spent so much time at the beginning of the semester creating different strategies because the strategy you select at the beginning of the semester can limit or boost the capabilites of your final machine.

This class really reinforced my time management skills. Throughout the term our team usually had two people at a time working in the shop outside of class time. At first it was very difficult to make the simplest parts for the vehicle because I was not used to using the machines. As the term progressed I became more comfortable using the machines and making parts took less time. I definitely gained a much better feeling of the proper way to use machines and tools in the shop. Every week we had to plan out who was going to the shop and when. This class is also balanced with 3 other classes so it was very important to make sure that I left enough time to get all my work done in every class. As team captain, I signed our team up on the machine shop website for the use of the mill and lathe.

ME 250 also showed just how important team work is. One person could not possibly complete the entire project. Every one must contribute which lightens the load and makes it possible to finish and make a great vehicle. Our group disagreed sometimes about certain aspects of the design of our vehicle but we eventually always came to an accord and were able to create a vehicle to execute our strategy.

In this class I also learned about many design principles and technical terms in the lectures. Under the leadership of Mike and Albert I learned about principles such as resolution, exact constraint, Saint Venant's principle, Occam's razor, and many others. Also I learned about many different parts such as different types of screws, bearings, and even about pillow blocks. Learning about SolidWorks was also very helpful. Jean was a great GSI and was very helpful whenever questions arose about SolidWorks or the design of our vehicle.

To improve the class the structures of lectures could be changed. Most of the information could be simply read off the slides so lecture could sometimes seem tedious, perhaps there could be more informative videos showing the design principles in action instead of mostly definitions. When videos were shown they were mostly very interesting while other information such as definitions was less interesting. Also the lectures could probably be 1 hour instead of 1.5 hrs which seems like a long time considering the lectures could be condensed to 1 hour. Also in the competition I was under the impression that intentional contact was illegal before a point is scored for the team initiating contact. Some teams actually had a strategy of initiating illegal contact. For next semester maybe the rules could be made more clear or disqualifications should be handed out because the rules clearly restrict that type of a strategy.

I could have improved my performance in this course by spending more time in the machine shop. Our vehicle was not too complicated, but by utilizing a different strategy the vehicle could have had a different design which would have enabled it to retrieve red sand filled balls in addition to the black squash balls. This design would be more complicated, but would have more potential for points and this machine would also require more hours in the shop and it would result in a more successful machine. Overall, this class was really informative as well as organized and I feel I have moved one step closer to being an engineer.

Brendan Person's Individual Reflection

Brendan Person

Course Reflection (Individual Weblog)

ME250 has taught me much about the aspects of design, teamwork, and machining.  I worked previously in a machine shop; however, I never used the mills or lathes before this class.  The project really helped me understand all of the steps of the design process.  First, we started with a basic strategy to use, then we picked a concept for a vehicle that seemed appropriate, then we designed a prototype that we thought would work.  Finally we used SolidWorks to model our vision, and then finally put our machining skills to work in the shop.  The SolidWorks training in this course was excellent and I am happy that I have gained much experience in the subject. 

This project involved a great deal of time, and therefore, time management.  We started on this project towards the beginning of the year, but somehow it still ended up being a tight fit to the deadline.  The machine shop got really packed after the break because every group had the essentially the same time schedule to work with.  Our team managed time pretty well, but the major problem with time occurred with our machine malfunctioned or a piece wasn’t machined correctly. For example, we had originally planned on using wheels that we bought online, but when we inserted the axle into the bushing, the hole was too small and the axle bent.  This problem forced us to act quickly and reinvent our machine using the wheels that were provided.  

The course was run very smoothly, except in my opinion, the lectures.  The lectures seemed too long and didn’t give enough useful information relative to the goals of the class.  Needless to say, the lectures did provide a strong base for the exam, but the 1.5 hr lectures seem too much for the material needed for the course.  The lab sections were run very well, and the grading was always very fair.  Jean was a great GSI, and even helped us earn a second chance in the competition when our wires were taken out by the other team.  In my opinion, the course can be improved in three ways: shorter lectures (or only 1 day a week), smaller discussion sections (it can get very packed), and a better spacing of requirements.  The requirements were spaced fine until about the last 3 weeks of class.  We went from having to have the MCM completed, to having 90% done within about 4 days.  I feel that if the MCM would have been due sooner, people would have spread out the times, and the machine shop wouldn’t have been so packed in the last week.

I could have improved my performance in the course by allotting myself more time to go into the machine shop earlier.  If I would have gone into the machine shop to work on this before break, I would have had better skills at using the machines, and I wouldn’t have taken so long to do the parts.  Another way that I could have improved my performance is to not mess up on the last problem of the exam (I lost 10 points from that one problem).  Overall, the class was actually entertaining and I was able to learn a great deal.  I am actually looking forward to 350 after taking this course.      

Ryan Rodeman's Individual Reflection

Before I say anything else about ME 250, I’d just like to say that this was easily the most fun I’ve had in a class at the University of Michigan so far. That being said, I also learned quite a bit in the class. Before ME 250 I had never done any kind of manufacturing. In this class, not only did I learn was a lathe, mill, and laser cutter were but I learned how to use them and use them properly. There were so many things about manufacturing that I learned, such as tolerances and what kind of parts need to have what tolerances.

I learned a lot more in ME 250 than just about manufacturing though, I also learned quite a bit about design and design principles. Before this class I always thought design wasn’t quite as important as the manufacturing, but I learned that a good design can go very far. First off, the better the design, the easier the manufacturing can be.  I learned that design is actually a very important process, like the Balltower competition was for us, when given some sort of problem or situation that you need to solve, first thing you should always do is come up with a design to help solve said problem. When designing, it’s very important to keep design principles in mind. Some of the more useful one’s for our team’s design included Occam’s Razor, keeping things simple, Repeatability, the ability to do the same action over and over, and Exact Constraint, the number of points at which a body is held is equal to the number of degrees of freedom that are to be restrained. Design was a huge part of what I learned in ME 250.

Teamwork and time management were also key to what we learned in ME 250. Teamwork was essential for the project. Everything we did was as a team so learning to work well in a team setting was crucial. One very helpful way to learn how to deal with future possible problems was the lecture with Russ Pitts. His lecture was both fun and informative, and very helpful. I am really glad that my team worked so well together and we did not have any problems along the way. I learned quite a lot about proper time management from this class. With a full semester course load it can be very difficult to find time to work on everything I need to do. In ME 250, especially, where the project is very time consuming, it is extremely important to make sure that my time is managed well. For this project I was able to do that. I learned how to properly manage all of my time so I could succeed in this class as well as all my other classes.

In my opinion, as I stated before, this class was very fun and interesting, but that doesn’t mean it couldn’t be improved. The biggest problem I had with the class was the lectures were bland and seemed almost unnecessary to attend in order to really do well in the class. All the necessary information that was given in lecture was on the slides so one didn’t really need to show up to lecture. Also, like I said, the lectures were bland. Maybe there could have been more interaction, such as the iClickers used towards the end of the semester. Other than the problems with lecture, I thought the rest of the class was run very well.

Lastly, I believe my course performance could have been improved in various ways. First off, time management, though my time management improved with the class, it always could improve even more. Other than this I felt like I worked very hard and feel like I did about as well in the class as I could.

In conclusion, I had a lot of fun in this class, but more importantly I learned a lot about design/manufacturing and teamwork/time management. Most importantly the skills I learned in this class I can use in real life situations in the future.

Bill of Materials (Addition to Final Documentation)

The bill of materials is shown below, but here is a link to the google document in case that doesn't work.


bill of materials

Final Machine Description

Throughout this entire semester we have been working diligently on completing our machine while devising strategies and eventually creating a module and design in solidworks which had the purpose of executing our strategy. The competition was this past Thursday and after only watching a few machines in the competition it was clear what the best strategy would have been in this competition. Our strategy was to retrieve as many of the four black squash balls as we could from the wave field. This strategy is both time consuming and inprecise. Our vehicle has an arm while not mechanical was able to achieve our goal of knocking two black squash balls off the wavefield. The best strategy would have been going for the red sand balls from the perches of the tower by use of an arm to dislodge the balls and then a funnel or tube to catch those balls. Our vehicle had two phases: one was to move the ball and the second was to secure it, but with this new improved strategy you can dislodge and secure the ball in one step.

Our final vehicle was smaller compared to most of the other vehicles in the competition. Our base and all of our walls were built out of aluminum. We used a double gear box with a gear ratio of 115:1. This gave us more than enough torque considering we only needed our vehicle to move and knock down a few balls from the wave field. Our vehicle was also faster than most vehicles in the competition. At opposite ends of our gearbox we have two shafts which were connected to two axles (which connected to the wheels) by flexible tubing. We were originally going to use 4'' diameter wheels but we realized the weight distribution of our vehicle might be thrown off and also the front compartment of vehicle would be unable to capture balls because it would be too high off the ground. So we used the wheels provided to us by the supply box. We also had two small arms at the back of both ends of our vehicle behind our wheels. The purpose of these arms was to move and/or capture any balls by the back of our vehicle. While good in concept, the arms did not prove much actual use considering their size and range.

Our control box was secured on top of our arm by velcro. We were originally going to put the control box and battery pack underneath the arm but this interferes with the arm so we decided to secure it to the top of the arm. Also putting the control box in this location also helps to even out the weight distribution of our vehicle. After what happened in the competition, we would definitely have made the walls of our vehicle higher in order to protect the wires of the motor and control box. In one of our games in the competition another team was able to pull apart the connection of one our wires which connects the control box to the motor and effectively made it so we could no longer move. To prevent this we should have made higher walls.

Overall our wheels provided very good traction with the use of sand paper. We had no problem turning and it was not difficult to dislodge the balls from the wave field because our vehicle was precise in its handling and maneuverability. This is one aspect of our machine that actually worked out better than we planned. Our vehicle was quite small so we could have increased its size without sacrificing too much speed so we wouldn't have been pushed around as much in the competition.

Our vehicle has 3 walls and a base plate. There are two walls on the right and left side of the base plate which extend past the front of the base plate and serve as the compartment for captured balls. Also there is a back plate which sits between the two side plates. Attached to this back plate is a hinge and this hinge connects our arm to the back plate. Our arm was made from the 1'' aluminum hollow stock. Attached the end of this arm was a prong which was also made from the 1'' aluminum hollow stock. The prong is secured to the arm by two plates on either side which overlap the two pieces. The arm was secured (in addition to the hinge) by a support beam which is secured to the base plate by two blocks on either side of the support beam. The arm as can be seen in the pictures rests on the support beam. The final parts of our vehicle were three bent aluminum pieces which rested underneath our base plate with purpose of pushing the black squash balls forward. Since our baseplate was above the ground when we tried to drive the vehicle without this innovation the vehicle would simply squish the black squash ball and be unable to move but this small altercation pushes the ball forward without letting it get stuck underneath the base plate.

After having a full design complete we painted the walls of our vehicle black and also adorned it with various decorative images. One of which was a Herman Cain Train wording on our arm as well as a Yes We Cain! slogan on the side of our arm. We also have a picture of two American flags on the back of our backarms as well as two pictures of Herman Cain our name sake on the base plate of our vehicle. Our design worked very well for the strategy we designed, but our strategy had limits, such as being unable to get red sand filled balls. Overall we were very happy our vehicle worked as we intended, but we now all realize even more so just how important selecting a strategy is and can result in you ending up with a vehicle that is limited in what in can do or a vehicle that can achieve all that you hoped for and more.

Recap April 9-10

     During this week, we have begun to test and do some practice runs on our vehicle. After some testing, we realized that we needed to resolder some of our wires. We also decided that we should add some walls below the motor so the black squash balls do not get run over from out vehicle. Using some of our unused parts, we solved this problem and proceeded to run some tests.
     Another problems we noticed was that our vehicle was not moving as fast as we thought it could. We added some sandpaper to the wheels which greatly increased our speed.
     After successfully running some tests, we also realized that we needed to add some color to our vehicle. We brought the vehicle home and painted some of the parts with glossy black paint and made some decisions about adding pictures to the vehicle as well to go along with our team name Herman Cain Train. A picture of the finished product can be seen below.

Finished Vehicle