Design and Manufacturing
At the beginning of the course, I had only ever used simple tools like screw drivers and hammers. I didn't know how objects were made, but now I feel confident with my ability to use a lathe machine and a mill as well. I think Bob and Marv did a good job teaching and were very patient with the unexperienced ME 250 students. Before this class, I would have hand drawn everything but now, I find using a computer and Solidworks is much easier.
Teamwork
Unlike other courses I have taken at Michigan, I feel this is the first time my entire team wanted to work hard towards a common goal. Normally I like to take leadership, but this time I feel Nick was the leader. It was a good experience to have to be a follower as well and listen to other people's inputs. Everyone contributed something special to the team as well. Amanda was good with computers, Nick and Tim had a lot of experience, and I think I was the creative one who came up with a lot of different ideas at the beginning. Our group worked very well together too. We had a couple disagreements, but in the end, we all came together to make the machine.
Time Management
I was skeptical about how much time we had considering we were still making CAD models with a few days left to build. Nick however had everything well timed out and with his experience he knew exactly how long the whole project would take. I would have liked to finish earlier, but we finished with enough time to run several tests and fine tune the smaller things. It was difficult to be efficicent though when the lab got crowded, so we would try to work at less busy times. I think we were a little crammed at the end and could have improved there.
Course Improvement
There are several things the course can do to improve. First of all, when we first started building stuff, I knew what a mill was, but I didn't really know how to use it. I think in lecture you should talk with more detail how to build objects. Perhaps do more of having an oddly shaped object and go through the steps to making the object.
Safety First. In lecture or lab I don't really recall talking about safety besides for wearing safety goggles. Sure enough, somebody drilled a hole through his hand later. These machines are very dangerous and I had a close call with the band saw myself. I think you should talk more about safety.
The rules and arena design and kits changed several times. It's hard to build a machine when the parameters keep changing. Please try to have rules set in stone from the beginning.
Personal Improvement
The thing I best improved on is working with others. In my life, I have built lots of little gadgets and random things but always by myself and not with others. My design was different from our final design and this was difficult for me to deal with, but in the end I had to trust my teammates. Also, whenever somethings needs to be done, I like to do it myself, but I learned I can use my teammates if they are not busy to help me out. At the end, I became ill with strep throat and the team had to work without me. I was afraid they would screw up, but in the end they did a fine job without me.
Monday, December 14, 2009
Sunday, December 13, 2009
Things I have learned in ME 250
Design and Manufacturing
The primary thing I learned about design and manufacturing is probably how to communicate my ideas to other people. I already had a lot of manufacturing experience on mills and lathes from high school robotics, and also welding and further machining skills from the Baja Team. However, several of my teammates had less experience, and I feel that I have started to learn how to explain machining processes during this class. I also learned how to make good engineering drawings that were clear because we couldn’t always communicate in person about what needed to be done. Often part of our team would be in the EPB CADing while others were machining, so clear communication was very important. I also learned about both laser and waterjet cutting, which I had not had experience with before. Both of these techniques were very useful to our design and were very cool to use. On the design side, I feel that I did learn more about all the steps taken in a design project. The lack of a a clear set of rules in the beginning of the class led to a more free and creative environment, much like what may be experienced in the real world at the very beginning of a new project. As the rules became clear, our ideas started to take a firmer shape, and we realized that we would be fairly constrained in the types of design we could pursue. As the final kit took place I also learned to be very minimalist in design because we didn’t have very much material to work with.
Teamwork
As mentioned above, I learned to communicate my ideas effectively without constant face to face communication. This became very important as our group was constantly in different places working on different parts of our project. Although we all had a good idea of our final goal, sometimes it was difficult to make specific ideas clear. It is always difficult to find a good balance between pushing your own ideas and accepting other ideas when they are better than your own, and I fell that our group did a good job at this. We mostly chose the correct places to really all get together and argue for our own ideas, but at the same time allowed personal creativity in other areas, were only certain criteria had to be met. Although we were far from perfect, I think we had a pretty good team dynamic, and the other classes we shared this semester also helped us to come together as a team when it came to crunch time.
Time Management
The most important thing I learned was that it is always the little things that will get you. Our team did a good job getting our major components drawn and manufactured early in the process, but were tripped up at the late stages because of string constraints. The string retraction, while important, was mostly left as a last minute “let’s just slap it together and it’ll work” type thing. This was very unsuccessful, and it proved to be our undoing in competition. We should have tried to find these issues early, but instead we were left scrambling as we broke thread after thread every time we tested our machine. Although we did complete everything on time, getting done a week early could have really helped our performance. However, given the time constraints we had, I believe we did the best we could and we did accomplish most of our goals on time.
How the Course can be improved
I think the major improvement would be a strict set of rules earlier. We were tripped up by rule changes several times and I feel this is unfair to the students. The rules should also have definitions for important terms, because several times we interpreted a rule one way but were later told that the Professor or GSIs interpreted it differently and had to change our design further. Finally, I think access to more metal stock would help. I think that only specialty materials should be limited, and things like Aluminum or steel bars should be available as needed to avoid partial solutions dictated by a lack of material
How I could have improved my performance
The major thing I should have done differently would be to have gone to OH or at least put more time into the HW assignments early on. Although I was very busy traveling with the sailing team, I still could have dedicated more time to them and done much better. This would be a major improvement for my grade in the course.
Reflection - Tim
Design and Manufacturing
I did not learn anything new about design or manufacturing, but I'm sure other people did. I was a part of the FIRST Robotics Team in high school for four years; the entire ME250 course was essentially a scaled down version of my previous experiences. I appreciate the massive effort that went into teaching basic design and manufacturing in the course. However, I noticed some gaps in the lessons that negatively effected students new to the process. This will be explained further in the "Course Improvement" section.
Teamwork
As opposed to Design and Manufacturing, I learned more about teamwork. Everyone on my team did their jobs spectacularly, that was not a problem. The problem arose when everyone was trying to work on the same design or machine piece at the same time. Everyone wants to help, but too many ideas or hands working on the same design or machine piece will smother it. Effective division of labor is an important lesson I won't forget. This problem never arose in my Robotics Team because people were often more concerned with eating the free food than working on the robot.
Time Management
I have a problem with time management. I hate being late, but I often get sidetracked easily and lose track of time. The milestones of the project have helped tremendously in my opinion. If there had been no milestones, things would've turned out differently for me. From this course, I learned that setting milestones will help more than simply setting a goal in the distance.
Course Improvement
The most important thing that needs to be improved is preparation of materials. We must have clear rules and objectives at the beginning of the course. This first course was fine though, seeing how it was a major change from before. The second thing I would do is create teams and start manufacturing a bit earlier. More time is always nice. It seemed like more material than necessary was presented for the first half of the course.
There needs to be more focus on teaching manufacturing. Design was taught well, but I saw many manufacturing mistakes during the course. For example, people did not know what parts needed accurate machining and what parts didn't. A drill press should not be used on pillow blocks for aligning a shaft, a mill should be used instead (one team had problems with the shaft grinding into a bearing). A band saw cannot be depended on for close accurate cuts, it should be roughly cut followed with milling. Another example, people did not know what fasteners to use for certain situations. Epoxy is easily broken in certain loading configurations (this was why one team lost). Putting screws (or even staples?) through wood isn't particularly effective. These are just small little lessons, but they can improve manufacturing quality a lot. This is important or students will create hard-to-manufacture designs that are ultimately inefficient.
Personal Improvement
The most important thing that could have been improved was time management. We rushed things at the end and created a working but un-optimized machine. If we had even three extra days, we could have eliminated the major problem bugging our machine.
I did not learn anything new about design or manufacturing, but I'm sure other people did. I was a part of the FIRST Robotics Team in high school for four years; the entire ME250 course was essentially a scaled down version of my previous experiences. I appreciate the massive effort that went into teaching basic design and manufacturing in the course. However, I noticed some gaps in the lessons that negatively effected students new to the process. This will be explained further in the "Course Improvement" section.
Teamwork
As opposed to Design and Manufacturing, I learned more about teamwork. Everyone on my team did their jobs spectacularly, that was not a problem. The problem arose when everyone was trying to work on the same design or machine piece at the same time. Everyone wants to help, but too many ideas or hands working on the same design or machine piece will smother it. Effective division of labor is an important lesson I won't forget. This problem never arose in my Robotics Team because people were often more concerned with eating the free food than working on the robot.
Time Management
I have a problem with time management. I hate being late, but I often get sidetracked easily and lose track of time. The milestones of the project have helped tremendously in my opinion. If there had been no milestones, things would've turned out differently for me. From this course, I learned that setting milestones will help more than simply setting a goal in the distance.
Course Improvement
The most important thing that needs to be improved is preparation of materials. We must have clear rules and objectives at the beginning of the course. This first course was fine though, seeing how it was a major change from before. The second thing I would do is create teams and start manufacturing a bit earlier. More time is always nice. It seemed like more material than necessary was presented for the first half of the course.
There needs to be more focus on teaching manufacturing. Design was taught well, but I saw many manufacturing mistakes during the course. For example, people did not know what parts needed accurate machining and what parts didn't. A drill press should not be used on pillow blocks for aligning a shaft, a mill should be used instead (one team had problems with the shaft grinding into a bearing). A band saw cannot be depended on for close accurate cuts, it should be roughly cut followed with milling. Another example, people did not know what fasteners to use for certain situations. Epoxy is easily broken in certain loading configurations (this was why one team lost). Putting screws (or even staples?) through wood isn't particularly effective. These are just small little lessons, but they can improve manufacturing quality a lot. This is important or students will create hard-to-manufacture designs that are ultimately inefficient.
Personal Improvement
The most important thing that could have been improved was time management. We rushed things at the end and created a working but un-optimized machine. If we had even three extra days, we could have eliminated the major problem bugging our machine.
Reflection - Amanda
What did I learn in ME 250? Here it is, broken down by category.
DESIGN AND MANUFACTURING:
Basically everything I learned, I learned in this class. Before ME 250 I made pretty much made nothing, not counting 6th grade shop class and a silly Engin 100 project. I guess I knew some of the design process, as made sense when we went over it in lecture, but the lectures gave names to steps in the process that before were fuzzy. I found all the info on mechanical components to be fairly interesting, as I didn’t know much about them before. It was nice to get a feel for each component in our kit before actually working with them and know what each component can do. I learned a lot about using the machines in the shop, too, as I had never really used them before.
TEAMWORK:
This class reinforced the things I have already learned about teamwork. If everyone is pulling their weight and getting along, things go very smoothly. If someone doesn’t, it increases everyone’s workload and annoyance exponentially. Also, things often take longer to accomplish when everyone tries to work together on everything. It’s often more efficient for group members to work independently and then come together for discussion. Playing to team members’ strengths is important, too. For example, a few of my team members had a lot of experience from robotics in high school, which made them the best people to start off our manufacturing and teach the rest of us how to do it. That being said, even if a team member doesn’t have experience, there were still valuable ways for them to contribute.
TIME MANAGEMENT:
My time management was decent in this class. One my teams’ reasons for designing our machine the way we did was so that we could finish manufacturing early and have plenty of time to test it. This didn’t really happen. Although the manufacturing wasn’t too complicated, we were still manufacturing things up until the week of the competition. This was partly due to adjustments that had to be made, but I think if we had started manufacturing earlier we could have made even more adjustments and figured out ways to make our machine better. For assignments that we had to turn in, we were often working on them the night before. Although this is not particularly outstanding time management, we still accomplished the things we needed too without too much last minute stress.
HOW THE COURSE CAN BE IMPROVED:
Just as the students could have managed their time better, I believe the instructors could have managed their time better by getting information out earlier. It would have been nice to have a complete version of the rules that wasn’t going to change at all at the very beginning of the class. I understand that this was a completely new way of doing the class, and I appreciate all the work that went into planning the competition, but I think it would have made things easier on us if we were better informed, earlier. Also, I think the kits could have been improved with less variety of materials, but more quantity.
IMPROVING MY PERFORMANCE:
I think I could have improved my performance by going to office hours for the lecture homework assignments. Those killed me a little bit. Also, as previously mentioned, time management could have been a better when working towards the milestones.
Wednesday, December 9, 2009
Machine Description
Our machine is very simple to understand. It consists of two essential modules: Tape Dispenser and String Arm. These two modules work together to slide a tape measure under the balls, lift them up, and form an incline to move the balls to the opposing slot. The details of the machine are described below.
Tape Dispenser Module:
This module consists of an aluminum framework, wooden box with wheels, tape measure, and motor assembly. This module is dedicated to holding the tape measure and extending or retracting the tape.
Aluminum Framework - This part is simply two sheets of aluminum plate spaced apart from each other with four aluminum posts. There are slots cut into the plate. The purpose of this part is to suspend the Wooden Box above the arena, mount the Motor Assembly, and provided a stable and secure platform for operation. This part also houses the control box.
Wooden Box - This part is constructed of four wood panels. Two wheels are pushed against each other inside the box with a set of springs. This part holds the Tape Measure in place between the wheels and allows the Motor Assembly to interface with the wheels.
Tape Measure - The tape measure itself. The end of the tape measure is cut off and curved so that it will move down the arena slot smoothly and follow along the walls.
Motor Assembly - The motor assembly is a Tamiya gearbox with a plastic gear. It's responsible for spinning the wheels of the Wooden Box, therefore causing the tape measure to extend or retract. It is mounted to the Aluminum Framework.
String Arm Module:
The module consists of a base plate, slot arm, motor assembly, and string spool. This module is responsible for pulling on the tape measure via the strings to help pull the tape through the arena slot. It also acts as a blockage to stop opponent robots from crossing over.
Base Plate - This part is a sheet of aluminum plate. It has a slot cut into it as well as L-bracket pieces mounted on the front. The Base Plate mounts all other parts of the String Arm Module and acts as a stable platform. The L-bracket pieces prevent opponent robots from moving through.
Slot Arm - This part is a welded tube made from steel plate. It is mounted to the Base Plate and extends down into the arena slot. It has has holes to allow the String to pass through. This part is designed to stop the tape measure at a certain height thus forming an incline for balls to roll into the opposing arena slot.
Motor Assembly - The motor assembly is a Tamiya gearbox with an aluminum shaft. It controls the retraction or extension of the string. It is mounted to the Base Plate.
String Spool - The string spool is Kevlar thread wound around the shaft on the Motor Assembly. The string itself is attached to the tape measure. The string runs through the Slot Arm as well.
Tape Dispenser Module:
This module consists of an aluminum framework, wooden box with wheels, tape measure, and motor assembly. This module is dedicated to holding the tape measure and extending or retracting the tape.
Aluminum Framework - This part is simply two sheets of aluminum plate spaced apart from each other with four aluminum posts. There are slots cut into the plate. The purpose of this part is to suspend the Wooden Box above the arena, mount the Motor Assembly, and provided a stable and secure platform for operation. This part also houses the control box.
Wooden Box - This part is constructed of four wood panels. Two wheels are pushed against each other inside the box with a set of springs. This part holds the Tape Measure in place between the wheels and allows the Motor Assembly to interface with the wheels.
Tape Measure - The tape measure itself. The end of the tape measure is cut off and curved so that it will move down the arena slot smoothly and follow along the walls.
Motor Assembly - The motor assembly is a Tamiya gearbox with a plastic gear. It's responsible for spinning the wheels of the Wooden Box, therefore causing the tape measure to extend or retract. It is mounted to the Aluminum Framework.
String Arm Module:
The module consists of a base plate, slot arm, motor assembly, and string spool. This module is responsible for pulling on the tape measure via the strings to help pull the tape through the arena slot. It also acts as a blockage to stop opponent robots from crossing over.
Base Plate - This part is a sheet of aluminum plate. It has a slot cut into it as well as L-bracket pieces mounted on the front. The Base Plate mounts all other parts of the String Arm Module and acts as a stable platform. The L-bracket pieces prevent opponent robots from moving through.
Slot Arm - This part is a welded tube made from steel plate. It is mounted to the Base Plate and extends down into the arena slot. It has has holes to allow the String to pass through. This part is designed to stop the tape measure at a certain height thus forming an incline for balls to roll into the opposing arena slot.
Motor Assembly - The motor assembly is a Tamiya gearbox with an aluminum shaft. It controls the retraction or extension of the string. It is mounted to the Base Plate.
String Spool - The string spool is Kevlar thread wound around the shaft on the Motor Assembly. The string itself is attached to the tape measure. The string runs through the Slot Arm as well.
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