Individual Reflection by Yundi Lin

Throughout the whole course, I learned many valuable knowledge about the design process, CAD modeling, manufacturing and prototype testing and troubleshooting.

For the design process, I learned that a good design is usually conceived from top down, ie, the big picture is worked out first before the details are finalized. Probably the most important thing in the design process is to consider the many alternatives and work out the best approach to the problem. I realized that this was a critical and yet very difficult task to accomplish. This is because at the start, we only have a rough idea of how our machine is going to work, yet this initial vision is going to determine how our machine is going to look like, and work, in the end. Using the Slot-Bots competition as an example, if the initial idea is not good, then regardless of the quality of engineering in the later stages, the final machine is not likely to win the competition.

Also, I learned that it is really hard to come up with a good, detailed design. The drawings we made initially may look good, but, as the saying goes, all plans fail upon initial contact with the enemy. I realized that throughout the manufacturing process, there are a lot of factors that can influence the manufacturing of a part. For most of the parts, imprecise manufacturing is the cause. However, there are other unexpected problems that I ran into, like imprecise dimension of the parts given. For example, I designed the box of our machine to be 12in by 9.6in. However, the piece of acrylic that we were given turned out to be slightly shorter than 12in. Thus, the cuts made by the laser cutter was not accurate and as a result, many other parts in our design was affected. Thus, I believe that in the future, I shall design parts that are smaller than the size of the material that I am given.

For teamwork, I realized that it is often better to have one person be overall in charge of one part of the project and let the rest assist him or her, rather than having everyone do the same things and then combine efforts. This is because I realized that every person has a different working style, and if two or more people are working on the same part, there can easily be a clash of ideals, for example, disagreeing on how the report should be written. Therefore, I think that it is better to have one person handle one part of the project rather than risking having too many cooks to spoil the broth.

For time management, I realized that good planning of work is really important, as time easily flies when one is working in the shop. Thus, my group usually hold a meeting the previous night to decide what is to be done the next day, rather than going to the lab and then working out what to do for each person on the spot.

I think the course can be improved by allocating us more time to manufacture and test our parts. I honestly felt that we had quite a lot of time to do the solid models, but the manufacturing time given was very limited. We often have to spent long hours in the lab, waiting for other teams to finish using the mill or the lathe, because everyone else from ME 250 to 450 is using the same shop. Also, I realized that it is almost impossible to just use the drawings we have to manufacture the parts, and then hope that everything fits together. There are most likely errors present, either due to errors in calculation or errors during manufacturing. Thus, we may often need to make multiple trips to the shop to make corrections to our parts. This is not helped by the fact that many others are using the same machines. I often experience up to one hour of waiting time for machine usage, and this hour could be put to use elsewhere, like testing.

I could have improved my performance in the course by making more careful measurements and calculations in the beginning of the course. I realized that a successful design require the designer to make calculations more precisely while the design is still on the drawing board, not while it is being manufactured. Using my team as an example, we could have realized early on that the bevel gear system will not work if we had made the appropriate calculations regarding torque required, and used the string idea instead. However, that calculation was not made, and as a result, we were staring at a nonfunctional machine 6 days before it was due to be completed. Even though we did manage to come up with a solution, I feel that we could have done much better by realizing that the gear idea will not work before we completed designs and made the necessary changes to our design.

Overall, I would say that I learned a lot on how it is like being an engineer, designing and manufacturing my own design and troubleshooting it. Also, I learned about how it is like to work in a team, especially team management and task allocation. Last but not least, I learned a lot about the different functions of the machines in the workshops and their capabilities, and machining techniques that are really hard to learn from just about any book.