I came into ME250 expecting it to be quite an involved class after talking with multiple students who had taken it previously, and boy were they right. Even though I have had a fair bit of design and manufacturing experience coming into this class, I have never been held to such a rigid and fast paced timetable. It seems like just a couple weeks ago that we were sitting down in the computer lab to begin the design of our machine. I am used to setting my own schedule and working at my own pace, knowing that I have a final deadline to meet and that I can work backwards from that point. This class though has taught me what it will be like working in industry where there are intermediate deadlines and goals throughout the course that are out of your control. The other biggest factor in our team’s time management came from the fact that my schedule was different from everyone else’s due to being in a different lab section; because of this, we had to make the most of the little time that we had as a full team. When we were able to meet as a full team, we had to be sure to stay on task in order to complete the things we needed to do in the time we had. This scheduling challenge was not as bad as it was initially made out to be though; and in the end I feel that it actually benefited our team. There are times in the design process where you want a large group, to be able to collaborate and brainstorm ideas and bounce concepts off one another, but there come a point where that large group dynamic begins to hinder design and becomes a burden. Once we had nailed down our concept and how it was going to work, it was much easier to sit down with only part of the team and design the nuts and bolts and fine details of the robot; its not possible to have four people trying to decide the location of a hole, and the design process ends up being much quicker when it is headed up by one or two people.
When it comes to the manufacturing of a design though, things get much more interesting. I have done a bit of manufacturing in the past, but nothing on the scale or precision of our robot. Being able to get hands on experience with amazing tools such as the laser cutter and water jet was one of the highlights of this course for me. Although our design was fairly complex, we took advantage of the precision tools that we had access to (laser cutter and water jet) to manufacture our most complicated parts so that the building of our robot was similar to the assembly of a car or some other pre-fabricated machine. Even with this simple approach though, we encountered unforeseen obstacles that added to our assembly time and set us back slightly. I learned that you can’t always count on holes to always line up, and that metal is a lot less forgiving then other materials such as plastic or wood. There were multiple instances where holes in our parts were correct when aligned with one other connecting part, but when the entire assembly was put together there was just enough misalignment to require re-drilling the holes. I also learned that even with computer controlled machines you can have make errors that affect your entire project. While we were water jetting our main base plate, the material shifted by about an eighth of an inch, changing the perimeter features of the design. We were able to overcome this issue with a slight modification of just a few of our parts, but it just goes to show that everything can’t go as planned.
One of the biggest things that I felt was lacking was an introduction to hands on manufacturing during the first part of the lab section. Our first opportunity to manufacture real components was with our own designs, which may not lead to the best first experience. A large portion of the design process comes from knowing what can and cannot be manufactured and how the machining process works. If machine training was taught before or concurrent to design, I think it would be much more beneficial and lead to more robust and well thought out designs. The digital world of CAD does not always transfer easily to the real world, and I feel that there is a lack of emphasis on that fact. My other concern is in regards to the electronics provided in the kit. Although it is useful to be able to choose the output gear ratio of the motor, the motors proved to be quite weak even with high gear ratios. I feel that the demand on these motors grows with the complexity of the problem to be solved, and that the current problem to be solved requires more powerful motors.
Overall I am pleased with my performance in this course, but I feel that the greatest thing that I could have done was stick to a stricter personal schedule. Even though we had deadlines and assignments throughout the design process, I feel that I could have been more productive and successful if I had set machine goals to stick to. Basically by saying what components I wanted functioning by a given date, I think our fabrication and assembly time could have been put to better use, and allowed us time to troubleshoot our robot in more depth and possibly solve our issue of underperforming motors.
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