ME250 Individual Reflection - Jenna Boeing

            Heading into this course I knew absolutely nothing about both design and manufacturing. Considering the class started with design, I will begin my reflection with just that. Before this course I rarely thought about how things were designed or put together (not very ‘Engineer’ of me I know!). However, after doing research on many of the topics brought up in lecture, I became fascinated by the variety of components that went into sound design. The more I learned, the more enthusiastic I became about the subject. Every time I sit at an unstable table now, I always look beneath it to determine the design flaw or the point of failure!

            In terms of manufacturing, I was terrified of going into the lab and operating such powerful machines, at first. Once I had used the mill for the first time, I fell in love with the process of machining. I am somewhat of a perfectionist; when I do a job, I do it to the utmost of my abilities. Machining seemed to compliment my anal retentive tendencies flawlessly, and I found myself playing a game of how accurate I could make the piece! With guidance and support from Bob and Marv (to whom I am eternally thankful!), I became a master of the mill and grew confidence in my ability to operate the machines.

             In terms of teamwork, I learned that the most efficient way of operating a group of people is to divide and conquer. I believe my group work could have gone a lot smoother if we had designated a team leader. Not a team leader who knows it all, but just someone who was comfortable dividing up the work to be done based on ability and keeping the group on target. On another note, this project taught me the importance of being selfless in your work when you are on a team. Comparing the amount of work you have done to that of another gets you nowhere at the end of the day, so why waste your time? If one works his or her hardest to be selfless, feelings of resentment will be non-existent, incapable of putting a damper on relationships between teammates. Of course for time management I must say what I’m sure most ME250 students would say: I should have started earlier. My team coasted through the beginning milestones, but when it got to the end, the work had just piled up. Work is hard to do non-stop and under the pressure of a deadline. My experience would have been much more enjoyable had we worked on time management and spent more time on the early assignments as opposed to doing the bare minimum.

            As much as I sometimes hated going through this class, I must say that in hindsight this is a very productive class. I learned more in this class than in any other class I have ever taken (however this is my first semester in UMich Engineering!). For constructive criticism, I think that the process of machining should have been started earlier in the course. A lot of time was spent on design concepts, and although I learned a great deal from this part of the class, I would have preferred if the time spent on it was shorter.  Several of the milestones I only spent about an hour on, whereas at the end of the course I was putting in 60-hour weeks. I would have learned the same amount in a shorter time period, it just would have allowed for more time in the actual shop. The time spent without beginning group work was also far too long in my opinion. Machining takes a great deal of time, especially to be precise. Compacting the experience into the last two weeks devalued the experience as a whole. I learned more in the last two weeks of the class than in the rest of the semester.

            If I had been more organized in this class I believe I could have done better. If we had been in the shop the second it opened, I believe my last couple weeks would have been less stressful. I should have encouraged my group to work harder in the beginning of the course and managed my time better. Also I wish I had spent more time taking advantage of the knowledge and expertise of Mike and Davor. A great deal of knowledge on this subject comes from experience and I should have taken advantage of their experiences. Lastly, I shouldn’t have taken so long to get on a machine. I was incredibly intimidated at first and I think that I let my fear get the better of me in the beginning. Hindsight is 20/20, but overall, I would not trade my experience in this class for the world and I am incredibly proud of the work my team and I did.

Individual Reflection on ME250 - Brian Thompson

ME250 was a very challenging, but fulfilling class. As a mechanical engineering major myself, being able to design and manufacture a machine from scratch was a great learning experience for me. I have taken a design class similar to this but I have not experienced such an in depth project from start to finish. Working in a group of four can be at the very least, a challenge. Having to work around each other’s busy schedules was one of the hardest parts of the project. By working around each other’s weaknesses and using each other’s strengths, we were able to come together and produce a quality machine for the contest. Manufacturing in the shop, was one of the most useful aspects of this class. At times the lectures seemed like a lot of information that was very abstract without a hand’s on approach. As we got into the shop it was much more useful to see what worked and what didn’t in our designs. Because the lab and shop time seemed so much more useful, I feel the emphasis should be placed higher in getting groups together earlier in the semester and getting them working in the shop as soon as possible. This is where I learned the most and I feel I can use this knowledge as a base to help my design for other projects in the future. As we neared the end of the semester, time was running short and tempers were running high. Even though some of our schedules were not the best in the final weeks of completing the project, I feel that the team worked well together and in the end, we all put in an equal and immense amount of work for the project. As the competition day arrived we had finally finished our machine and it felt great. I was happy with our success in the first round, and that is all I could have asked for. As for the second round, our design could not hold up to the competition, who pinned our front arm to the flipper even after we had reached it first yielding our machine useless. It was very frustrating watching the other team score as my controls were rendered useless. I feel that if I were to do a similar project, I would spend more time designing a machine to combat such weaknesses. One way to improve my own performance would be to work ahead on the project early in the semester when we had more time to focus on the class instead of having to do other extracurricular activities at the end of the semester. We ended up having to design some parts right up to the deadlines of the final machine, and this was very stressful on the team as a whole. In the end this has been one of my favorite classes of my college career. I hope to be able to use the knowledge I’ve gained, and build from it in the rest of my studies and hopefully into my career as a mechanical engineer.

Final Victorious Secret Blog Post!

We are sad to say farewell to ME250, but we will leave you with some parting words…

Our team was seventh seed overall starting the competition on Wednesday. We dominated our first match with the other team not scoring at all. However, in our second match we did not score. We reached the flipper first but were over powered by the other machine. We were disappointed we never got to compete against a top robot to deploy our defensive strategy. Overall, we were happy with our performance.

Our final design was remarkably similar to our initial idea. From the beginning our plan was to focus on quality manufacturing and not on winning the competition. Due to time constraints some of our manufacturing fell short of quality for which we were striving. However, our robot preformed exactly how we design and we could not be prouder.

Here are some photos of our final robot and a video of our competitions.

Round One

All I could bear recording of Round Two!

Looking back, we could have design our machine differently. The concepts utilized by Team Boss were unbeatable. The ideas of using a spring loaded flipper opener and a ramp to get the balls into the slot were brilliant. 

Here is a link to the final Bill of Materials
https://spreadsheets.google.com/pub?key=0AjuRz9rabCdLdFJCcUpGMjI4XzRhWXZkdUtiZXlxUFE&output=html

Final ME 250 Thoughts of Callen Richards...

ME 250 was my second mechanical engineering class and it was very different from my first ME experience of ME211. The design and manufacturing aspect and hands on portion of this class was the reason I chose it for my elective. I really enjoyed learning the steps involved from initial problem, to beginning problems, to final solution. The lab portion of this class was the most helpful in learning about design and manufacturing. However, it seemed that we were always to rush through our assignments in lab before time ran out. Our group even had difficulty getting our MS6 reviewed because other groups took too long getting theirs reviewed. The lecture portion of the class seemed to be a slight waste of time. The concepts covered were rather common sense. There were a few concepts, such as how to properly do an engineering drawing were interesting. Other concepts would have been better explained in lab. The drill speed, feed rate, etc. were difficult to understand when shown just on a slide. I would consider changing the lecture time to one hour and the lab time to one and a half hours.

I have had a lot of experience with teams throughout my college career. This team was one of the most fun and at the same time challenging teams I have worked with. I think the main difficulty with getting the team on the same track was that we were not assigned teams until late into the term. Additionally, we did not do many team assignments until even further into the semester. The restrictions of shop hours made it difficult for me to budget my time. I think one of the things our team did well was dividing up tasks to different members. We had one person focus on the solid model, two on the mill, and another on the lathe. While each person focused on a specific task, we all took part in each process to have everyone involved entirely in the class.

My overall impression of this class was a good one. Getting to the end of the class and having an actual working robot was quite rewarding. I was very excited when we scored so highly in the seeding round and did so well in the first round. I was a little disappointed that we did not get to show off our defensive blocking arm of our robot. I would have like to compete against a top robot. There are a few things that I would have changed about the class. There should be more little steps in the process evaluated. There should be a deadline for the final concept and more machining deadlines. There is always a big rush towards the end of a project, but with the restrictions of the shop hours, the time needs to be better allotted. Smaller milestones throughout the build would help teams feel less panicked in the last few days. The size requirements should also be thought through further for the different challenges of the new arena.

If given this option, I would like to take a class like this again. I am sure it would be just as exciting and challenging!

Final Thoughts...

ME 250 was one of my favorite classes and, at the same time, the most difficult class I have taken while at the University of Michigan. Throughout the semester I learned a lot about manufacturing and design as well as furthering my teamwork and networking skills. I liked the class because it gave me my first opportunity into design and manufacture of a machine. Most people have an idea of a good design, but few rarely ever get a chance to create it. I liked the fact that we not only were pushed to come up with a solution to a problem but to also build it and see the problems that oftentimes occur when theory is transformed into reality. Problems that arose included: making designs that were too complicated, poor time management, and difficulty sticking to deadlines. While I did in fact learn a lot this semester, there were also some things that I did not find as helpful. I did not find the lectures to be very helpful or useful in furthering my knowledge. I understand that technical information needs to be taught, but it is hard to explain how to use a mill or how to use a nut and screw—these things need to be done hands-on and used multiple times to gain a true understanding. I felt like too much time was also wasted on individual work and not enough time was utilized to work as a group. I see how individual design is important, but I think collaboration is more important to further ideas that one individual might have. Along the lines of the lectures, I feel as though it is difficult to explain design and the creative process. These are things that should be explored by the individual, since design is not necessarily something that is so black and white. I understand the assigned milestones and individual assignments were designed to keep the individual and group on track; however, I feel like the class would have benefitted both myself and my group as a whole even more if we had been allotted more time to work on our design. We then would have been able to see the theoretical ideas that had once seemed “plausible” fail and figure out simpler or more elegant solutions to deal with those problems. I feel like the quality of teaching and shop training was very good and helpful. However, I feel like the “learning” did not begin until the last 2 or 3 weeks of class when I was actually in the machine shop playing with tools and seeing what worked in reality and what only worked in theory. I think that is an important idea to discuss and discover, and one that I think was not covered well enough. An idea always seems good on paper, but bringing the idea to reality and actually creating it can be quite challenging and maybe even impossible. One of the things that I found the most beneficial and simultaneously the most detrimental to the outcome of the class, for me, was having a team. I like having a group of people to bounce ideas off and receiving feedback, but that only works when everyone is involved and dedicated. I was lucky to have a pretty dedicated group, but occasions did arise when people were absent and “busy.” However, I learned an important principle this semester that I have rarely said or actually done before: if you want something done, you have to do it yourself. With that I thank you for a great semester and hope everyone has a safe and happy holiday. ☺

Team Video!

Here is our team video for the competition. Enjoy!!

Crunch Time!

MS 9 is due this morning and things are coming down to the wire. We are completing the assembly of our machine this morning and will be done before our lab time. We hope that everything will be functioning well and we will only have small tweaks to do before Wednesday!

Below is a picture of some of the parts we have machined and assembled throughout the week. All of our team has become quite familiar with the machine shop and the auto shop. We used a variety of tools to manufacture our parts including the mill, lathe, heat treating, laser cutter, welding and more. During our machining we focused on quality, not quantity and that caused us to be in the shop for long hours perfecting our pieces.

Our team has been very busy machining and assembling all last week and a lot of the weekend. We will continue putting the finishing touches on assembly and completing the "business side" of the project. We have finished accounting for all of the purchases and trades we have made, and we came out under budget.

Please come back in a few days to see a pictures and a video of our final robot!

Working Video

Sorry, the previous post of our video did not upload properly. 

10 Days until Slot Bot Competition!

The slot bot competition is in 10 days and we still have a lot of work to do.
This is a video of our functioning MCM. This is the front flipper arm that will slide down to open the flipper. The head of the arm is hinged so it will fit within the 12"x12"x24" starting size requirements. The arm will be mounted onto our base plate and the arm will be moved with our motor using a rack and pinion.

The bearings of our flipper arm were the most challenging design aspect of our MCM. The Delrin bearings clipped into place, just as we had planned.

We have finished finalizing our design and the components for our machine. For MS8 we completed the drawings the bill of materials for each piece of our machine.
In order to make our design easier to fabricate we have designed our machine to use the same pieces in multiple locations. This will allow us to make duplicates of a piece rather than making many different types of pieces.
We have reserved machine time of the mill and lathe for next week. We hope to have finished all our parts by the end of the week to use next week for troubleshooting. We have 22 different drawings for the types of pieces we will fabricate.
Below is an example of some of the pieces we are currently working on. Each pieces is sitting on top of its respective SolidWorks drawing.

 We hope to update our blog with more finished piece pictures and have assembly done by mid-week!

MS7 Manufacturing

For assignment MS7 our group decided to manufacture the end piece of the flipper arm and the clip-in bearings which allow the flipper arm to slide.

The clip-in bearings were laser cut from the sheet of polyoxymethylene (more commonly know by DuPont's trade name, Delrin). Although we felt our design would function properly, we were advised to only cut out one clip to double check that we were correct. Fortunately, we designed the clip properly and it will be able to clip in. The clips will guide the inner part of the flipper arm while allowing it to glide through easily.

Delrin Clip-In Bearings

The end piece of the flipper arm required two main pieces to be manufactured: the support piece and the arm grabbing piece. The support piece was fabricated from 1/2 inch square stock. The material was cut to length and then the square section was milled out. Holes were drilled into the piece for attachment to the grabbing piece.

Aluminum Support Piece

Finally, the grabbing piece was manufactured. In order to create the bend in out piece of aluminum, we first had to anneal metal.  The purpose of annealing is to heat the metal above the recrystallization temperature create a homogeneous structure. This in turn will induce increase ductility and relieve internal stresses in the material. After we annealed the metal, we quickly quench using water. The pieces was then bent to approximately 30 degrees (+/- 10 degrees) and holes were drilled using the mill. The support piece and the grabbing pieces were attached to create the end piece of our flipper arm.

Assembled Grabbing Piece and Support Piece

Finalizing Our Design

This week our team focused on material selection. First we focused on material selection for machined parts and we also determined which parts we want to order. As time and quality are limiting factors in our manufacturing process, we want to allocate our resources accordingly. We will be ordering certain parts we will not be able to manufacture in our given time or that we do not have the expertise to manufacture to the degree of precision we desire.

We have also continued to improve our design to use our resources wisely. We have re-designed the end piece of our flipper arm. Our first design was over complicated and would require a large solid piece of stock material to be laser cut. Our new design can be made from smaller stock material using the milling machine.  We have also determined the motor mounting position for our moving arms.

We continue to finalize our design and we hope to start machining our parts early this week.

Original Flipper Arm End Piece

Flipper Arm Motor Mount

Most Critical Module

Our team has decided our most critical module is our flipper locking arm. This is the most critical module because without gaining access to the flipper we will not be able to score. We are still working on the other modules and trying to think of ways to play the game more offensively.

ME 250 Schedule

Here is a link to our schedule for the rest of the semester:

http://goo.gl/eDad

Our Design Concept

Our concept for the Slot Bots competition employs the two arm approach. One arm will extend to lock the flipper arm in the open position. Another are will use a sweeping motion to push the balls into the open slot. A third arm will act to block the other team from reaching the funnel. This arm will be able to move from one side of the table to the other, forcing an opposing team to either get to the other side faster or find a way to drive over the arm. Below two views of our design. The first is a three dimensional view of the bot. The second is how the bot will function on the playing table.

Three Dimensional View of Bot

View of Bot within the Table