Monday, December 14, 2009

Ira Goldberg - Individual Reflection

To say the road traveled in this class was a difficult one would be an understatement. Between mismatched schedules, components and modules not working as intended, and nearly missed deadlines, it was beginning to seem that our project was the embodiment of Murphy’s Law, “Anything that can go wrong, will go wrong.” However, it was not all doom and gloom in the end. Through hard work and perseverance, we were able to step up to every challenge put in our way and produce a machine that was simple, effective, and most importantly, able to perform how it was designed to function.

Even though I would have to say that this has been the most stressful and time intensive classes I have ever taken, the end result has made it more than worth it. The experience I gained in the ME shop has been more than invaluable. Though I would have to admit that I made my fair share of mistakes during manufacturing, I was able to learn from these mistakes and make a better product as time went on. Before this class I could say that I had basic knowledge about the mill and lathe. Now, I can confidently say I can use these machines along with other tools in the shop to produce very precise custom components, a skill I will take with me for the rest of my engineering career.

As my other group members have pointed out, time management and communication played a big part of how our machine came together and it’s pace. Unfortunately, our group quickly learned that our schedules didn’t exactly match, and unforeseen circumstances prevented our team from being able to make vital decisions and produce critical parts as a whole. During these critical times, with group members missing, exams looming, and deadlines coming closer with each passing second, a great deal of frustration set in. It came to the point where I was probably pushing myself too hard trying to get everything I could for this project.

But out of the need to get things done and my frustration, I did my best to enact minor design changes to streamline manufacturing and ensure a working product. Though some of these changes were considered temporary by the rest of my team at first, the ideas behind most of them were implemented, or even adopted outright with minor changes. Everyone in our group had great ideas, and the machine really is the culmination of all of our thoughts put together, but stubbornness in taking criticism and adopting each other’s ideas hampered the early design process. It wasn’t until we started putting components and modules together did we start to see what parts of the design were working and what was not meeting expectations. It was at this point that everyone was able to get on the same page and start working toward the same goal on our final product. If we had a bit better time management and group dynamic, our design would have been optimized to its greatest potential, but the end result was more than satisfactory.

We may have had many issues along the way in getting our machine done, and it may not finally come together until the final days before seeding and competition, but seeing our final design in action was more than a rewarding experience. After a couple minor design tweaks, we were able to create a machine that during seeding was able to push all but two ping pong balls and all the squash balls over the divider. And seeing that our machine was seeded 4th, I would say that our design met the expectations that were given to us. Just witnessing our design going up against others in competition and succeeding made me forget of all the hardship and be proud of the fact that I made this thing.

But I have to say, if I were taking this class again, I would really hope that a few things were changed about it. As a member of a FIRST Robotics team in high school, I was excited to hear that we were being given the opportunity to compete. Unfortunately, unlike in FIRST, we weren’t given any details on kit parts, control systems, or the rules until after we started our group designs. I personally feel that many designs would have been better thought out if we had been given all of this information from the get go. It was more than frustrating trying to think of a design when I didn’t even know if it was feasible or not. Also, especially during build time, it seemed like many of the later milestones were not finalized until last minute. MS7 particularly stuck in my mind, as we weren’t given details on when to sign up to show our parts until the day before. Seeing as this was during an exam week, and everyone in our group had at least two exams, it did not seem fair to give us such late notice. The beginning of the class was also a bit rough in terms of scheduling. Three homework assignments a week put its toll on me, as this class provided about half my total homework for all my classes.

Other than these criticisms, I would say that the class gave me valuable engineering experience. We can learn all we want in books, but this, practical engineering experience, is how engineers really learn. Being able to physically touch a part you just made, seeing how a module really moves, and seeing an overall design come to life is more rewarding than doing calculations all day. Our robotics mentor in high school used to always say, “design is an iterative process.” This class and this project showed me that this saying is very much true.

Some Screenshots of our Solid Model

Here are some shots so you can compare to the photos of our machine a few posts down. (That and some of us are just pretty proud of our work with SolidWorks...)

Individual Reflection - Mike Ross

As a veteran of the FIRST Robotics Competition in high school, I probably had more experience with the design process coming in than most of my classmates and teammates. I had twice before seen a design through from beginning to end, and done my share of CAD modeling and part fabrication along the way. That experience, while it helped me to guide my team with a steady hand, did make me a bit overconfident in my own abilities and ideas. I did however manage to keep an open mind throughout, which wasn’t hard, what with the multitude of Type A personalities on our team.

Working with my team was a somewhat frustrating, but ultimately rewarding experience. Every member of our team, myself included, had strong opinions on the direction of our design at various points, occasionally to the point of stubbornness. This may be one of the reasons our design process bogged down a few times fairly late in the process. However, every decision we eventually made was made as a team, having explored multiple options, and I believe this due diligence made our final product better because of it (albeit at a slower pace than we would have liked). Every member of our team brought something different to the table, and I think we all complemented each other well.

I do appreciate the opportunity this class gave me to revisit using SolidWorks (which I used on my FIRST team), as well as machining on the mill, lathe, etc. because it’s been some time since I’ve used any of them. It’s always good to stay practiced, and I feel much more comfortable around all of them as a result of this opportunity, which is never a bad thing.

So in the end, our machine came together, almost exactly the way we designed it. With a few tweaks, it functioned about as well as we could have hoped. There are only a few things that bother me about our final machine. One: we had an issue with two gears meshing because I failed to adequately constrain the end of a motor shaft in the design. While we came up with a mostly functional fix, it is a problem that could have been avoided with a little more effort early on. Two: We did not anticipate quite the pace at which the matches would play out, possibly because we did not have much time to practice with our functional machine or other teams. That could have led us to Three: our lead screw extension mechanism was simply geared too low to score quickly at the beginning of the match. Had we dropped the planetary gearbox from 16:1 to 5:1, I think we could have scored much faster and made a much bigger statement in the competition. Oh well. We learn more from our failures than our successes. Live and learn (to test more) I suppose.

I must say, at this point I am pretty relieved this course has come to a close. While it is always exhilarating to see parts of my ideas go from vague sketches to concrete, functioning reality, I am thoroughly exhausted. The last three weeks, especially, have driven me (and as far as I can tell, my classmates) to our collective wits’ end. Some of the fault undoubtedly lies with myself and my team, as we underwent several minor and major overhauls of our design plans fairly late in the game. However it still seemed to me that the course was unnecessarily back-loaded. I believe some of the early milestones could certainly be condensed, to give us more time to actually work on our designs, before the work in our other classes begins to pile up as well. That brings me to another point. I would have really liked to have the game rules much earlier than we did. I appreciate that this format is new to the staff as well as the students, but fleshing out a concept is extremely difficult and tedious when you have only a vague idea of the problem’s constraints. Even if the rules have to be updated frequently at first, it is still preferable to any attempt to design without any references.

Sorry, if that was a bit of a rant. I would like to say that I did not expect this class to be anything like this, and am certainly glad it was. I can’t imagine making a tape measure or a flashlight could be nearly as exciting or engaging.

Detailed Pictures of "Veronica"

To highlight some of the individual components and modules of our machine, here are a few close ups for your viewing pleasure.

The Machine


Pillowblock for Lead Screw Bearing and Mounting Bracket for Arm
Interior of Upper Arm: Acrylic Hex Brackets, Pillowblocks and Bearings for Lead Screw, Turned Down Hex Shaft, and Bushings for Hex Shaft
Detailed shot of Bronze Bushings and Hex Shaft turned to 5/16th inch Diameter
Rotational Module for Arm, as well as Mounting Brackets for Telescoping Module being worked on
Bracket Designed to Constrain Motor Shaft Movement due to High Torque:
Torque required to lift the arm was putting too much radial stress on the unconstrained shaft, preventing the gear from properly functioning. This was designed to allow only one axis of movement in the shaft.
A View of the Mechanical Components of Our Machine on the Arena
Machine Nearly Fully Extended in the Arena
Our Machine Actively Scoring During Competition

Sunday, December 13, 2009

Individual Reflection - Michael Townsend

Although the first portion of this class seemed overwhelming, the process we went through to get to a finished machine taught me a great deal. I learned a great deal not only about general engineering principles and concepts, but also about working with a team to complete a common goal.

Prior to my experience in ME250, I had very limited background with basic manufacturing processes. In manufacturing the individual pieces that made up our final machine, I learned a great amount about the precision that needs to go into such processes. I also gained a good understanding of how to perform processes like milling, turning, and drilling. I feel that in learning how to do all of these things in this class, I will be much better prepared for challenges I will face in ME350 and ME450.

What I feel were the most important lessons learned through my experience in this class are those in teamwork, time management, and organization. I was apprehensive about trying to pick a team, especially since I did not know anybody in my lab section. It is always an uneasy feeling knowing that you are going to embark on a semester long engineering endeavor with people that you really don’t know anything about. I realized, though, that it was all part of the experience of the class and that I would learn a great deal from it. In picking our team and our initial discussions about how we wanted to approach the problem given to us, I found that I ended up in a good group. We had a wide range of experiences and capabilities, and every person was the type that I knew would be willing and able to get things done.

Once our team was picked and we started the process of designing and building our machine, teamwork and time management became very important. We all have busy schedules, so it took a lot of effort on everybody’s part to decide when to meet and get things done efficiently. In doing this, I learned the importance of communication in a group setting. Without each of us communicating with everybody else, we never would have been able to meet some of the deadlines we were presented with. Overall, the strict timetable we were presented with, as well as the necessity of cooperation in order to produce a working machine, taught me these lessons and will be extremely beneficial in my future experiences, both in similar classes and in my life after school.

As far as improvement of this course goes, I feel that there is definitely a great deal that can be done to make the semester move smoother. At the beginning of the semester, I was extremely overwhelmed with the amount of assignments we were required to hand in. Not only was it a lot of work for this class, it made it extremely difficult for me to keep up with the work I needed to do for my other classes. Also, I felt that the details of the contest were relatively disorganized throughout the majority of the semester. As the semester progressed, I did become more satisfied with how the class moved. When the homework and CAD assignments were done and the majority of our time was devoted to the design and manufacturing of our machine, the class seemed to be far more rewarding than it previously had. It was nice to see an actual product come from the time and effort we were putting into the project. Although the course had great room for improvement, I feel that it was a good experience, and taught me many things that I know will benefit me in future projects.

Final Team Post






Final Bill of materials:
https://spreadsheets.google.com/ccc?key=tu_sqkuMm3LA8psXtB_CqdQ&hl=en







Our final machine went through many different steps before becoming our final product. We originally planned to build a conveyor belt that would collect the balls at the top of the arena and then would drive to the other side to score points. However, through our design process we came to decide this would not be as effective in competition. For this reason, we decided to build an arm that would rotate and extend into the arena.
When we first came up with this idea we were going to build a car with an arm that could drive. Upon further analysis, we began to see that getting the car to line up and drive straight would be difficult. We also saw a car as being easier to block and play defense. Building a stable arm that would be able to reach all parts of the arena and even into the opponents’ side became our final project idea. It would be able to reach all parts of the arena, play defense, and be difficult to defend against.
Through the process we ran into various issues that required our engineering skills to come to a final solution. One main problem we encountered was lining up the motor with the gear on the hex shaft. In order to solve this problem we built a bracket that held the two gears closer together. This resulted in a working machine and kept the gears from being pushed apart. We were very proud that our idea actually worked and saved our machine from not working in competition. Our final machine ended up being a mechanical arm that fit into the slot and could rotate and extend. This was very effective and could scoop over almost all of the balls.

Eric Zech: Individual Blog

At the beginning of ME 250 was very annoyed with the class. I didn’t think our assignments were contributing to manufacturing and design process. I actually regretted signing up for this class as a technical elective. However, as the class progressed I began to have a greater appreciation for what we were doing and came to really like the class.
The amount of physics we had to do in the beginning did not make sense to me. I though the class was about building and design. Later on, we began to build our robot and I understood the importance of the physics and analysis before the building. Physics is part of design and this became very apparent when we realized our arm did not have enough torque. We didn’t account for enough weight for the steel arm and had to gear everything down in order to allow the arm to rotate. If we had done better analysis prior to building, we would have saved time trying to fix this and could have improved another part of our machine.
The CAD design and manufacturing was also very rewarding. Being able to design something on a computer and then going through the process and being able to see a finished project was very rewarding. The moment we finally got our arm to rotate and extend without problems was one of my happiest of the semester. I am very glad I took this course and I think I learned a lot about the amount of work needed to make something great.
Working in a team was very helpful for this project. We all had different ideas and were able to mesh our ideas into a final project. Seeing things from other’s points of view and working in teams is very important and was a very beneficial part of the course. As a team we were able to work through any issues we had encountered and eventually came together in the end to make a completed, working machine.
Time management was a bit of an issue for our team. My knee surgery and other conflicts that arose during the term made it difficult to meet deadlines. Although we did meet all of the milestones, we had to spend a lot of hours trying to get it done. Looking back, I would have taking beginning design ideas more seriously so we didn’t have to struggle to solve these issues in the end. This would have made meeting deadlines less stressful for our team.
Overall I was happy with the course. I think some of the beginning assignments did not contribute well to our final project and I think the lectures should be more focused on example design processes. It would have also been helpful if the project had more focus in lectures and not just discussion. I think groups would have produced better machines if this had been the case. I also found I had to learn a lot of the CAS on my own because lab went too fast for me to keep up and learn the program.
Looking back, I think ME 250 will help me in the future as a Chemical Engineer. If I could go back and retake the course I would have tried to be more creative with ideas to win the competition early on in the design process. After watching the actual competition, I think a good design would have been to grab balls on my side (including the heavy balls) and simply dumped them out of play because most teams couldn’t mess with any of the heavy balls. I think we would have done better in the competition if this had been the issue.