Weblog Final Documentation Individual Reflection - Corwin Stout

At the beginning of the semester, I knew vaguely what the names of the machines in the shop were called and what they were used for. I had taken a CAD class over a year ago, but had used a different program that was 2D based. I had never built anything for a class that was more interesting than a balsa wood boomilever. Through the shop training, help from more experienced friends, and having time to experiment, I was soon able to create the parts we had designed for our machine. Solidworks was hard to understand at first, but after we finished the third or fourth CAD assignment I was able to make a model of anything I could think of.

We had a great group dynamic. We had no true leader, each of us lead the group in different ways. Michael was the perfectionist who kept us on track and didn't let us submit any work that wasn't error free and well organized. Mac had the most experience in the shop, and helped us by letting us know when our designs could be improved to make manufacturing easier and by looking over our shoulder in the shop. Vince was pointing out problems with the machine and proposing solutions all the time. The concept of having a spring-loaded, telescoping arm lifted by a winch was my idea, and I came up with various other ideas throughout the semester. Our group got along very well, and our final machine only worked as well as it did because of each of our contributions

Our group spent many hours on each assignment, and many more overall hours in the shop. We put in as much time as was necessary to get a good job done. However, several tasks we performed as a group of four could have been accomplished by one or two people. We also made sure to have the full team's approval before working on the machine, which kept the quality of the machine higher but meant that time was spent explaining ideas instead of manufacturing.

The class could be vastly improved if the rules of the competition and building materials are given to the students within the first couple of weeks, rather that halfway through the semester. We were asked to design a machine early on without knowing exactly what it had to do or what it could be made out of, and as the rules were clarified and the kit contents were finally released we had to constantly change our designs. Many creative ideas were abandoned early on in the semester by students who gave up on their Ferris wheels and conveyer belts because they didn't know if their idea was too complex and if it would be breaking any rules later on. Also, the homework should have been graded and returned much faster. We can't be expected to improve our work if we don't know that the last work we did wasn't correct. This was especially the case for our CAD homework.

I could have done better in the class by going to office hours for help in Solidworks for the first couple of assignments. I didn't realize that I had been using the wrong units for my models until after we got our second assignment graded. I also should have been more persistent in getting help on the FRDPARRC tables.

Weblog Final Documentation Individual Reflection - Vincent Ji

It has been quite a journey in ME 250! Having the perception of this was going to be a fairly easy class, I was blown out of the water by the amount of work during the first few weeks of the semester. Before I realized how mentally unprepared I was, I had already fallen behind on my homework grade. It was also difficult to grasp the important aspects of the class. For a while, I didn’t know how to apply the lecture materials on the homework or project. But as it was getting deep into the semester, I started to get a hang of the class. Seeking help from the GSIs and using design principle in my project analysis, I was adjusted to the right mode for this class. The biggest lesson I learned from this class was to never underestimate a class just because some older people said it was easy.

Looking back to all the busy work I did, it was probably the most important knowledge in engineering. From CAD to design principle then to machining, I have never left a class without learning. As an amateur to machining, I was completely unfamiliar to milling and drilling. Thanks to my experienced teammates who showed me how to use operate those machines without having catastrophic failure. Speaking of the team, I am very pleased with how well we were able to work together. Since day one, everyone showed strong professionalism. Although there were a lot of difficult and time-consuming tasks during the semester, all the members had always been dedicated and willing to contribute to team’s success. Through the semester, I think work was divided evenly and everyone always stayed with team until all the work was collectively completed. When the workload got heavier, everyone was able to overcome their busy schedules and accommodate other members. After every meeting, we always planned out the agenda for next meeting. Thinking ahead, I could always leave enough time so we never had to rush at the last minute.

Maintaining good team chemistry really came a long way toward our team’s success. The key to working in a team is personality. Fortunately, we get along with each other very well. Late night at the Dude, a joke or two could really make time go faster. Although bouncing ideas off each other sometimes could be vigorous, everyone was able to keep it professional and finally reach the best solution.

Despite the fact this class required a lot of work than the ones from previous semesters, I think ME 250 definitely prepare me better for ME 350. I found it very rewarding when we won the competition at the end of the term. All the hard work and all the late night parties at the Dude finally got paid off.

To make ME 250 a better experience in the future, it is important to have clear instructions about the game and materials from day one. Time management, in my opinion, is another component of this course needs to be improved. Students should be given more than one month for machining; at the beginning of the semester, the focus of the class should not only be on analysis because any change during machining will make the previous analysis completely useless. I really think this is the most interesting course I have taken and have faith in this class will become an excellent learning experience for future students.

Weblog Final Documentation - Individual Reflection by Mac Van Loon

I really enjoyed my time in ME250. After hearing what previous courses were like and how easy they were I feel like I will be more prepared for ME350. The lectures were very informative and gave a lot of good information about design and manufacturing. I often used them as a reference when I had questions about designing parts such as constraints and gearing. While the machine shop experience was not unfamiliar ground to me I still thoroughly enjoyed the experience. I found it much more difficult to machine in the busy environment of the ME shop than at a more organized business.

Teamwork was a very important aspect in this course. I feel like our team did not click right away and we had our disagreements but we managed to keep it professional and work very efficiently together. We were very good at bringing all of our ideas together and giving each other advice. Our team also did a good job at breaking up the tasks. During part of the manufacturing I worked on the arm mechanism with Corwin while Vince and Mike worked on the car. We had a lot of speed bumps to overcome when manufacturing our machine and I felt that our team did an excellent job coming up with creative solutions to our problems. In the end we designed and manufactured a very effective machine.

Our team did a good job with time management. We made an effort before all of our meetings were over to determine what was on our agenda for next meeting and when we would be able to get together again. There were a few cases where it was hard to get our schedules to match up so we were not always able to start meetings with every team member there. In these cases we would make sure to let the team members that couldn’t make it in time what had happened at the meeting. I believe that we could have taken less time manufacturing our machine if it weren’t for the large number of problems we had with the car.

I felt that the course has improved from what it used to be. I understand that it was a new system but I would have liked it if the course was more organized from the start. It would have been nice to have known what was in the kit and what all of the rules and electronics were before we started designing. Some of the homework that we had to do was very long and I wish that it was more relevant to what we were working on for our project. Other than the homework and the lack of information in the beginning I felt that ME250 was a successful course that helped to give students the needed experience in CAD and in the ME shop to do well in future design courses. I believe that my performance in the course was good but I think that I could have worked harder in the later design stages. I would have liked to have finished manufacturing the machine earlier so that we could have had more time to practice and work out bugs. It would have also have been nice to have this time to possibly find a way to get the squash balls.

Weblog Final Documentation- Individual Reflection by Michael Wang

I learned a lot from this semester and I would say that MECHENG 250 had a lot to do with that. First of all, I have never helped designed anything and then machined it. I was prepared for a difficult manufacturing process as I have little experience in the area and could see myself making parts that did not fit the specified tolerances. However, I was caught by surprise how many times we had to redesign or even come up with completely new solutions. Overall, I improve my skills in SolidWorks (CAD Program) through repetition and also got better at machining with the mill, lathe, drill press, and band saw. In addition to new skills I acquired, I also gained insight into how the creative/design process works and acquired a general knowledge of mechanical components (ie. Bearing, pulleys, gears). I think that this class has prepared me well for the next Design and Manufacturing course, MECHENG 350.

I really enjoyed working with my group. I think that we had pretty good teamwork and were very efficient. In the beginning we were bouncing ideas off each other and figuring out what would work and what wouldn’t work. I think that this was the key to our success. We collaborated and added all our strengths together in order to figure out the best solution. Furthermore, we all shared the workload of the project equally. Some of us did more machining, while others designed and performed calculations. As always, arranging meetings with our busy schedules was tough, but when we worked together we got our work completed even if it took us late into the night.

Similar to our teamwork, our time management was also pretty good. We made all of the deadlines for our project and did well on the assignments. This was in part due to the fact that we never had to cram the night before a project was due and rush through it. We followed our schedule and were able to foresee any big time investment early. As with all of the other groups, the end of the term and the competition snuck up on us. At the end we had to make some sacrifices in our machine and had we saved more time/resources could have still improved our machine more.

This semester has shown that this course has a lot of potential. Firstly, I understand that this is the first time this new format is being tried out, but this class was made a lot more difficult because of the lateness everything was revealed to us. On the other hand, I think the content from lecture was useful, but that it could be condensed into just a couple lectures. This would allow for more time to begin designing the machines. I also didn’t think that the lab sections on CAD were all that useful. I would have rather completed the CAD assignment on my own during class and have the GSI there for questions. I also think the project/competition could be improved. Having the thin (0.02” clearance) in the slot limited the designs very much. Having a wider slot would allow teams to be more creative. If the slot were made to be wider than one machine, then teams couldn’t just park their cars and just play defense. This would help to make the competition more exciting as there would be more action. Another solution is to just have two of the original slots in one arena instead of making a bigger slot. Also, making the slot shorter and not so tall would allow more strategies such as conveyer belts (F.A.I.L.) and slot loaders (Stiga) to work better as well introduce new concepts such as a shooter or vacuum designs.

I could have improved my performance in the course by increasing our team's interaction with our GSI and Professor. We could have run our ideas by Professor Hart and Jean to see what improvements we could make to our machine. The day before the competition, Professor Hart did offer some ideas about how to get the squash ball, but by then it was too late to try to change our machine.

Update #6 Final Team Documentation

Final Summary of Machine

Our initial concept of a telescoping arm lifted by a winch remained our concept throughout the semester. Ideas that came later were using a 20 lb steel plate as our main body to anchor the machine in place, using the winch to pull not only the arm but also the release pin to let our inner arm telescope out, and putting flaps on our base plate to reach into the slot to keep the machine from moving side to side. Another great addition was our car that we added late into the semester. The car was very basic, consisting of our double gear box direct driving two small wheels and a wheel in back for some reduction in friction. Though the car did nothing to score and was the lightest and possibly least powerful vehicle in the competition, it got in the way of the other cars and prevented them from scoring. During our quarterfinal and semifinal rounds, our car was able to stall the other cars long enough to keep them from scoring until it was too late.


Our designs changed constantly throughout the semester as we learned the limitations of springs, pvc pipe, and the shop tools. Our final design consisted of a winch (planetary gear box at 400:1) and a telescoping arm mounted on a base plate that had flaps to secure it to the slot. The winch was attached to the end of our inner arm using braided fishing line.
Our machine never broke in any way, never got scored on, and scored an average amount of 288.2 grams (compared to our opponent’s average score of 170.6 grams). We found it interesting that though the cars with arms designs were seeded relatively higher than mounted arms, the finalists from each bracket each had mounted arms and had auxiliary vehicles to disrupt other cars. Cars have a high scoring potential when unopposed. In a head to head competition, the cars couldn’t score against each other well because they both drove along the same path and interfered with each other, while mounted arms did not have this problem.


Results
Awards: Strongest Machine (Murphy's Law)

First Round Murphy's Law(289) Vs. DaFever(152)

Photo Courtesy of AnnArbor.com
(http://www.flickr.com/photos/36693965@N04/4174519063/in/set-72157622851153057/)

Second Round Murphy's Law(289) Vs. Team Rocket(177)

Quarter Finals Murphy's Law(277) Vs. Ping Pong Predators(180)

Photo Courtesy of http://me250-f09.blogspot.com/

Semi-Finals Murphy's Law(289) Vs. Sei Jin's Army(171)

Finals Murphy's Law(297) Vs. Team Legend(173)

Slot-Bot Champions: Murphy's Law
Thanks to Professor Hart and the GSI for a fun Slot Bot Competition.

Photo Courtesy of http://me250-f09.blogspot.com/

Final Version of BOM (12/11/09)

Team Introduction Video

Check this out!




http://www.youtube.com/watch?v=_nwufdsnmDM

Back-up Video

Finished Machine/ Test Run + Manufacturing tips

We have finished the car and are in the progress of testing our devices.

Manufacturing tips...
1. When possible (tolerance don't matter that much or can be filed down) use the hack saw and not have to wait in a long line for the vertical band-saw.
2. If you use fishing line and tie knots in it, put some superglue on the knot. This will keep it from undoing itself.
3. If you want to accurately change the hole of something that rotates, turn it on the lathe and do not use a drill press to make the hole. (This is hypocritical because we actually used the drill press to make these holes)
4. When tapping holes, use cutting fluid.
5. Go into the shop early to avoid the crowd.
6. Don't be afraid to ask for help.

Update #5 Recap of Week of Dec 1

Winch coupled to the motor

Platform lays on the arena

Arm connection to mounting platform


Inner arm pushing PPBs

Car sitting on the arena

This has been the most eventful week of the semester. We started the week with machining angle supports and cutting chassis plate for the car. As we moved on to assembling the car, we realized it couldn't turn effectively. So we decided to use one wheel in the front to increase the car's turning ability. After turning the car shafts, soldering the motor wires, and neatly arranging the wires in order, we finally finished making our car! The new car has double-tired wheels attached to the motor. This provides more stability when our car being pushed by other opponents. We believe this car will work effectively against other team's offense.

As far as our offense mechanism, we completed all the machining parts for the platform and driving winch including angle supports and shafts. We geared up our winch motor because we want to speed up our offense process and start playing solid defense before the other team scores. When we put both of the angle stock on the platform, we found that the two shaft holes are perfectly aligned. So we had to turn the shafts on lathe machine so it can rotate smoothing while being driven by the motor.

The competition is only days away. We are in the final stage of testing and minor remodeling. After months of hardwork, we are ready to see how well our machine works against the other teams.

Schedule Update (Nov 30)

http://bit.ly/2MUoRd

This Google Spreadsheet contains the most recently updated team schedule.

To Do List...
1. Finish Machine
2. Test Machine/Make modifications as needed
3. Finish blog
4. Attend competition

Update #4 (Recap week of Nov 23)

Photographs of MCM (Extending Arm Module)

Picture of the release pin mechanism

Picture of the inner arm attached with pulling string

Photograph of Steel Plate

Photographs of the Outer block attached to the taped threaded rod

After a late party at the Dude last Tuesday, we finalized all of our engineering designs including car, winch holder, and all the components associated with our machines. We also made a few changes to our original design. First, we add two slices of polyethelene to the inner arm; according to Saint Venant's principle, this can prevent jamming of the telescope. Secondly, we changed the location of the string attachment from the outer arm to the inner arm. After testing our design, we found that there is a major friction existed between the inner and out arms. Pulling the inner arm helps tremendously on overcoming the friction and allows the arm smoothly scoop the PPBs over to the other side. Lastly, we inserted a treaded rod inside of the inner arm; this rod guilds the spring and prevents jamming.

With only a hand full of working days left before the contest, there is still a lot of work needed to be done. We are definitely ready to spend hours and hours in the shop to finish all the machining by the end of this week. This is the most critical stretch of this project. We can see the light of victory, those who stay will be champions!

Update #3 (Recap week of Nov 16)

Corwin Cutting the Inner Arm


During Wednesday's Lab session, Corwin and Michael did a great job cuting the taper on the band-saw. The finished surface was very clean and smooth. Besides finishing the parts for MS7, we took a further step in terms of finalizing our design. Since we had some problems with using a string to constrain the sping inside the outer arm, we are now adopting the idea of using a rod to keep the sring in line. We also added another hole on the inner block to make this design possible.


Simplicity has been a key design principle of our project. As our car design is being remodeled, we will continue to keep everything simple while functional. Majority of parts for our car are given in the supply kit and avoid complicated machining.




Picture of Machined Outer and Inner Arm

Update #2 (Recap week of Nov 9)

Update#2

We recently redesigned our car which now has a more stable base and double-motor feature. We are also in the process of ordering parts that are provided by the class. Some of the parts include rubber wheels, nylon, and countersunk screws. Over the past weekend, we finished manufacturing our inner and outer arms. Mac helped the team drill the required holes on these arms. We also experienced our first incident in the machine shop. Mac accidentally broke the drill bit while working on drilling a hole on the block and left a flaw on it. Definitely, this is something we will try to avoid in the future.

As the due date of MS7 is coming up, we still have to finish cutting and adding filet to the end of inner arm and laser cutting a steel metal sheet to make the winch base. Also we are planning on remaking the inner block and possibly moving on to the next stage of our manufacturing plan. Hopefully, after this busy week, we are going to finalize our design for car and all the arm components.




Picture of Machined Outer and Inner Block



Picture of Platform in CAD



Picture of Car in CAD

Update #1 (Recap week of Nov 2)

Update#1

For this week, we ordered the spring off of McMaster and purchased the Outer Arm, Inner Block, and Outer Block for Speedy Metals (See above Bill of Materials). We are holding off cutting the spring until we complete the rest of the machining because we spent our own money and don't want to replace it if we make a modification to another part that will effect the required length of the spring. We have completed the CAD model for the MCM (arm module) and continue to think about modifying the CAD drawing for the rest of the components. We will work on the CAD models for the car and the mounting modules in the weeks to come.

Picture of Spring



Picture of MCM (arm module) Drawing



Picture of Outer Arm Drawing



Picture of Inner Arm Drawing



Picture of Outer Block Drawing



Picture of Inner Block CAD/Drawing

Murphy's Law Schedule

http://bit.ly/2MUoRd

*Note-See orange section of spreadsheet*

Strategy & Machine Concept

Our team decided on a scooping strategy and a drawbridge concept for our offensive machine and a driving strategy and pushing car concept for our defensive machine. The offensive machine is bolted to a steel plate which sits on top of the arena and it held in position with tabs that rest inside the slot. A telescoping arm is attached to one end of the steel plate. This arm has a spring in it which pushes it down to the bottom of the balls. On the other end of the steel plate we will have a winch motor which will pull the telescoping arm across the bottom of the arena and up the center barrier. Once the arm moves the balls up the center arena divider our car will be driven to the other side to defend against the opposing team.












This is the orientation of how the Arm Module and Pushing Car will sit on the arena.

This is the Pushing Car without the ramp sheet metal covering the internal components.