Ryan Villarosa - Individual Reflection

ME250 is my favorite ME course so far. Working on the project was probably similar to working as an actual engineer in design. The class definitely got me more prepared as an engineer. At first, I was dreading this class since the first day. The project intimidated me because of how difficult it sounded and how much time I would need to spend on it. However, making the machine with my teammates was a fun and very valuable experience. I learned many new things in this class.

I was introduced to all sorts of components. Components that I thought were the most important were gears, fasteners, and bearings. Choosing a gear ratio was crucial to the project. We wanted our machine to move at a certain speed, so we had to choose the gear ratio that would’ve supported that speed. Gear ratios also give torque, which is sometimes important to design. Ultimately, we didn’t have to consider torque for our design. The concept of using different fasteners, whether we would use screws or bolts, was important in building our machine. In order for our machine to be stable and robust, all the connected parts were required to be attached with the correct fasteners. I thought bearings were most interesting among all the other components. Bearings made it possible for our machine to move efficiently as intended.

Manufacturing was my favorite part of the course because it was hands-on. The machines at the ME shop, such as the mill and lathe, are frequently used by engineers. I’m glad that I had the opportunity to learn how to use them. I got to learn many tools that I was unfamiliar with, especially the caliper. I also learned how to solder electrical components together. Having experience with these tools and machines will definitely come in handy in the future.

I already have prior experience in working in a team. I thought that Engr100 is the best course in terms of teamwork. But I was able to improve time management while in my ME250 team. This semester, I had a busy schedule including work and my other classes. The manufacturing process of our machine was the most time consuming. My other classes took place in the afternoon. Waking up earlier and spending the entire morning on making our machine was adequate.

There are a few things that I thought this course should improve on. The introduction to the ME shop wasn’t effective. We had to take training sessions two months before we even started building our machine. I think training sessions should take place much later so that remembering everything about the shop is easier. I feel that the exam was long and I didn’t have enough time to finish it. I think that the exam should be a little shorter in length, or maybe add several minutes. Even though my team and I finished the project on time, there should be more time for teams to build and test their machine. It’s probably best to assign the MS assignments earlier, especially the Most Critical Module.

The only thing I could’ve improved my performance in this course is my involvement in the design of our machine. An example of this is not coming up with the dimensions or materials of each part. Having more involvement would’ve resulted in me being a better designer as an individual.

I thought that everyone in my team was hardworking and was determined to do well in the class. I’m glad I was able to work with them all semester. I wish them the best in the future. We managed to finish 2nd in the design expo, and I have to say that I'm very proud of that achievement.

Derek Napierala –individual reflection

Overall I thought ME 250 was a great course. Going into the class I had slim to none experience working with metal, however in high school I had constructed many projects out of wood. At first working with metal scared me, I thought it would be much more difficult than wood and take much longer. However in this course I learned how to cut and shape metal (primarily aluminum) and get it to perform in a way I expected it to. I learned that metal is a much more reliable material than wood and while there some challenges to making it, with careful planning it can do much more than wood ever could.

Upon entering this course my approach to designing was to try something and see if it worked, if it didn’t adjust the design and make it better. However this course forced me to learn the value of taking the time to analyze a design in order to produce a better finished product. It is not always the best idea to jump with both feet in, and as I learned in the machine shop, without a proper drawing producing parts is almost impossible. Many errors in this project could have been accounted for with better initial preparation. However there is value to building a part in the shop, as limitations in a design are imposed with certain manufacturing techniques. For example, when designing the axle for our machine initially there was one single tapped hole through half of the axle for the set screw. But in order to tap the hole, clearance had to made through the entire axle, therefore I had to increase the hole depth to go through the entire axle. This just shows that both designing and manufacturing is important, because while you can design for most everything, there will always be one little glitch (if not many) that has to fixed after construction. Yet a good design will eliminate most of these glitches and produce a better functioning machine.

Another very important aspect of this course was teamwork. I was fortunate enough to have an amazing team; everyone on it was hardworking and exceeded my initial expectations. As a team we were able to decide upon an initial design, deciding what was too outlandish and what would work as expected. This method worked very well as we ended up going with a fairly simple machine, going after the balls on the front table and on top of the tower. What surprised me in the competition is that no other team was able to successfully score a ball from any other area of the arena besides the front table. This just shows that our team was able to come to a realistic final design and one that performed exactly to our expectations. Also working as a team taught me the importance of organization as we always had to work on the project together, and plan in advance when we wanted to work in the machine shop. I feel this is a very important life skill, because being organized saves lots of time in the long run.

While I learned a lot from this course there were areas to be improved upon. I felt that there was a lot of down time at the beginning of the semester during the planning session and the end was very rushed. Designing is important but it did not need to take as long as it did, and some of the deadlines could have been pushed forward in order to give more machining time at the end of the semester. But I did think the course was taught very well and the competition at the end was the highlight of my semester.

In conclusion I thought that this was a very valuable course and learned many new skills. This class taught me how to problem solve real world problems as well theoretical, but I know I will retain the practical knowledge I learned from this class for a long time. In terms of individual performance, I do not think I could have done much better as we ranked first in seeding and second overall in the competition. This course was a great benefit to me; I gained more confidence in my choice of mechanical engineering as a major and eagerly await design courses in the future.

Austin Murtland - Individual Reflection

Foreword:

ME 250 was one of my favorite classes I have taken in the engineering school, and it has assured me that I am in the correct major of mechanical engineering. I enjoyed every aspect of the course, from developing an initial strategy and design to working in the machine shop for hours at a time. This document will outline what I learned about designing, manufacturing, teamwork and time management. It will also outline what could possibly be improved in the course, and how I have used what I learn to improve as a student and engineer.

Designing and Manufacturing:

Before I entered this class, the only designing experience I had was being design editor of my school newspaper, and I had absolutely no machining experience. Furthermore, I had never used (nor heard of) a mill, lathe, or band saw. Simply put, the training sessions for the course terrified me, and I thought I was going to fail the class because other people knew a lot more than me.

Therefore, everything I have learned about designing and manufacturing has come from this course. In terms of designing, I learned the importance of having a clearly defined goal in mind, as well as the importance of drawing out sketches to help explain concepts. The reason for this is because my team member who was mainly in charge of the Solidworks model had to re-design the machine multiple times, simply because we changed simple components to improve our machine. Had we spent more time planning every specific aspect of the design, it would have saved us all a lot of time.

Teamwork and Time Management:

I truly pride myself on being a good team member and managing my time well, and I did so before this course as well. Still, this course improved my ability to work cohesively with a team, and definitely took a large chunk of my time this semester. In terms of working with a team, this is most I have ever worked with a class-assigned team on a project thus far into my college career. While I have worked on teams in courses such as engineering 100 and marketing 300, I usually tried to divide the work up at team meetings and then finish my tasks on my own. However, in this course, we always had to work together to solve problems and create the best design possible, and therefore, I hardly ever worked alone on ME 250 assignments.

In terms of time management, everyone on our team was fortunate enough to not have class before noon on Tuesdays and Thursdays (once lecture ended). Therefore, we spent nearly every Tuesday and Thursday from 8am-12pm in the machine shop for the past four weeks, in addition to some Mondays. Personally, I have a lot of commitments outside of my coursework, and was not able to work in the afternoons. Therefore, I had to dedicate a lot of early mornings to ME 250.

Improvements for the Course:

I thought this class was organized quite well. Still, I have two key suggestions. First, I think the initial stages of the course take a bit too long, and there is not enough time for manufacturing. Given the stages of the design process, where you initially start with different strategies, concepts, modules and components, students sometimes get too ambitious with their designs. They forget to realize that there isn’t enough time to actually manufacture these designs. Therefore, my team was at a large advantage because of the simplicity of our design, which worked out well for us, but was slightly unfair to other students.

Also, I think the material for the exam is a little excessive. Personally, I think there should be a more concise study guide where students are required to memorize 20-30 vocabulary words, so you don’t have to look through 16 lectures and guess about which vocabulary words might come up on the exam. However, I thought the other parts of this year’s exam was much more achievable than the practice exam we were given.

Conclusion:

Overall, I do not believe I could have improved my performance in this course. Our machine ranked first in the bracket and placed second in the actual competition, and therefore, I think we were more than successful. Therefore, I will conclude with how this course has benefited me as a student and engineer.

In addition to being in the engineering school, I am also in the Ross School of Business. The reason I applied to RSB is because I did not believe I would enjoy being a “true engineer” for the rest of my life. However, this course has made me reconsider. I absolutely loved designing our machine and manufacturing it, and this project has made me contemplate possibly being a designer as a career. I think it would be awesome to design cars for GM or design oilrigs for BP, so I will definitely look more into a more engineering-related internship this summer. Additionally, I look forward to ME 350 and 450, which will hopefully be as successful as my experience in this course!

Jake Atkinson - Individual Reflection

ME 250 was one of the most challenging and time consuming classes I have taken here at the University of Michigan so far. That being said, it was also one where I learned a ton, and one that I actually had fun in doing so. Coming in to this class, I couldn’t even begin to imagine how I was going to build a remote control vehicle and actually understand what I was doing. However, I learned so much about design and manufacturing, and was even able to construct a second-place machine in the process.

Before starting this class, I had no idea how to use a lathe or mill, I couldn’t tell you what a gear ratio was, and I had no clue how a control box, motor, battery, and gear box can function to turn an axle. But now, I know all of those things and I even have a fairly in depth understanding of each of them. It is amazing how much you can learn when you are working on a hands-on type of project.

I now understand how basic machines function and how components and processes work together to achieve the desired output. Furthermore, I have learned how to do simple analyses and calculations that provide insights into how a machine or certain components might perform given a specific situation. I also learned how to use a ton of different machines and tools in the shop, and I now even know most of the terminology for different tools and parts. Finally and most importantly, this class taught me the entire step-by-step process of designing and manufacturing a machine, from start to finish.

Aside from pure new knowledge, I was also able to hone my teamwork and time management skills. Throughout the semester, everything we did was done in a team of four students, and there was a lot to do. Therefore, we all had to make sure that we were working well together, which resulted in efficient use of our time. I think this is one reason why my team did so well in the competition and ultimately created a great machine.

However, there was definitely still room for improvement. One thing that we soon realized was a mistake, was coming to the machine shop without a detailed plan for how to manufacture a part or a clear drawing that was fully dimensions. We learned the hard way that a lot of time can be wasted in the shop if you have to continuously look up the machine running speed or the drill size for a specific hole, etc. Moreover, this creates chaos and disorganization in the shop. So, if I had to do it over again, I would make sure that our whole machine was fully planned out and designed with detailed drawings and manufacturing processes before starting to actually build it.

Overall, I think the course was a great one and I really only see one area for major improvement. Specifically, I think a lot of valuable time was wasted in the beginning of the semester. While obviously it is important that students first learn the necessary material in lectures before trying to implement it, I think things could have been done a bit more efficiently. I would suggest condensing a few of the original lectures, especially the one about creativity and teamwork, because as students at U of M, a lot of this material is either review or simply common knowledge. This way, the whole process could be moved forward by a few days and people wouldn’t be cramming quite as badly at the end.

Bill of Materials

The formatting for our bill of materials was not working well. Therefore, we have created a link to our google doc bill of materials:

Bill of Materials

Our final machine could not have come together any better. After many early hours in the machine shop, we were able to construct our machine to the exact specifications that we originally intended, and we are all thrilled with the overall capabilities of "Bot."

The building process definitely tested our capacity as engineers and problems solvers. We had issues with all three components of our mechanism: the driving mechanism, the front tray, and the arm. These problems ranged from press-fitting the axles into the bearings to finding a way to start with our arm extension bent and to have it expand, and even included bending the metal and the assembly of our front tray.

In terms of a description of our machine, we have:
-The driving mechanism: Our machine's driving mechanism works with a dual gearbox motor that control the front two wheels, which have an almost 4" diameter and a foam surface. In the back, a ball caster functions as a third wheel.

-The front tray: Using the water jet to cut out our front tray pieces, we bent these to make sure there wasn't too much friction between the tray and the balls. We then assembled these pieces by using 1/16" sheet metal bent into 90˚ brackets and using sheet metal screws. It is used to collect the balls and transport them to our scoring hole.

-The arm: The arm is just tall enough so that it doesn't exceed the 18" height limit, and it has an L-shaped piece attached to a spring hinge that expands after our machine starts moving. It is used to knock balls of the perches of the tower.

Finally, as you can see in our pictures, we painted the machine to make it look "nasty." The orange and black design is sure to scare away any formidable opponent.

Team video

Week Four (Nov 21 - Nov 27)

There's less than two weeks until the ball tower contest! Fortunately, we have made a lot of progress on our building and manufacturing, and we think we will be able to finish by the end of this week. Last week, we completed all the machine work for the most critical module, which is completely assembled and looking good! The only small issue we had was with the axles, which we had to re-lathe so they would fit into the bearings.

We also began the construction of both the arm and the front tray this week. In terms of the arm, we cut the main piece, and drilled and tapped the bottom of the piece (so it would attach into the MCM) and the side of it (so we could attach the pieces that knock balls off the tower perches). We also cut the steel threaded rod and screwed it into the top of the arm. As for the front tray, we used the water jet on Wednesday to cut out the tray pieces. Unfortunately, one of our triangular cut outs got caught in the jet and messed up one of the side tray pieces. Therefore, we have to go back after break to re-cut one of the side trays.

In the next couple weeks, we are going to have to assemble the front tray using sheet metal screws and bent 1/16" aluminum stock. Originally we were planning on welding the pieces together, but Bob informed us that it would be easier to use sheet metal screws to assemble it. We will include a picture of the tray construction when it is complete. Additionally, we have to figure out how we are attaching the L-shaped component at the top of our arm. The spring hinge came in, but we have to drill new holes in it, and when we tried using the mill to do this, the hinge bent a little. Therefore, we think we're going to have to use a hand drill to drill the holes.

Although this is our last blog post before the ball tower contest, look for The Team, The Team, The Team to be a top contender in the 2011 Fall ME250 Ball Tower Competition. We'll each post a blog after the competition, and hopefully we have good news!

Week Three (Nov 14 - Nov 20)

Everyone on our team is getting ready to celebrate Thanksgiving this Thursday! But before we can eat turkey and watch football for 12 straight hours, we have to get through this week, as milestone 7 and 8 are due on Monday and Wedsnesday, respectively.

For milestone 7, we had to complete 3 manufactured parts. While we have begun progress on almost every aspect of our driving module, we only have 6 parts fully completed. These 5 are the acrylic base, the right and left side tubing, the back side tubing, and the (2) wheels. We completed those early last week using a variety of processes, including the band saw, the laser cutter, the mill and a broaching tool.

Meanwhile, we have begun making the bushings and cutting and lathing the axles. However, we still have to finish each item by putting a knurl on the bushings and a mill for the axle set screws. Once all of this is done, we will be able to assemble everything by press fitting the axles through the bearings and into the wheels, and then our MCM will be complete!

Once we completely finish the MCM module, we are going to start building our front tray. Our first step in doing so will be to cut out the aluminum plate using the water jet. We're all pretty excited to use this machine, since we didn't get to see it operate during lab when the air pressure wasn't functioning. If we are efficient as a team, we can also drill the holes, bend the aluminum, and possibly even weld the parts together by the end of the week. This would give us a lot of time after break to finish the rest of our design, and make sure that we have the best machine by the ball tower competition!

Week Two (Nov 7 - Nov 13)

Over the past week, our team has met several times in an effort to finalize our Solidworks model. We wanted to complete the entire design, bill of materials, and step-by-step manufacturing plan before starting to build our machine so that we could make sure we could trade for or buy all our materials with plenty of time to get them shipped. We did run into a couple problems while designing our arm and front tray. The first problem arose when designing the arm.

During the entire process, we planned on using the 90° or 180° torsion spring that is provided in our kit, but we realized there was not a good way to connect either spring to the arm while ensuring durability. Therefore, we went online and purchased a spring hinge, which appears to be a perfect solution. This component combines our idea of having a spring and hinge separately attached, and makes the machining much easier to build.

Additionally, we realized that on the front tray of our machine, we want a 30° angled piece at the bottom of the tray to avoid having too much friction between the balls and the ground when pushing them around the table. We originally only had this angled piece on the back wall, but we realized that when our machine turns, we may have the same problem on the side walls. Therefore, we had to add this design to the entirety of the tray. We also thought it would be easier to just bend the 1/16" aluminum to make the 30° angled piece at the bottom, as opposed to attaching an extra component.  Thus, we had to redesign the tray on Solidworks and adjust our list of materials and manufacturing plan. This makes the construction of the front tray much easier, as we will just have to cut out the aluminum, bend it, and weld it together.

Now that our design is complete (pictured below), we will be able to start the construction of our machine this week. We plan to start building the driving mechanism in class on Monday, and use lab time on both Tuesday and Thursday to hopefully complete our most critical module. Once this driving mechanism is finished (and working!), we will begin the front tray construction. Because it is the most difficult component to construct, we do not intend to to start building the arm until the front tray is attached and we have gotten a better feel for working in the machine shop.

Week One (Oct 30 - Nov 6)

Our goal so far this week has been to finish everything necessary in order to meet with our GSI for the most critical module (MCM) milestone. Our MCM is our driving mechanism, which is shown in the picture below. A large part of the MCM assignment is to create engineering drawings on Solidworks that include specific dimensions. One of our key struggles in designing our driving mechanism was deciding whether to put the motors and axles of the wheels on the top or bottom of our base platform. After looking at the dimension of the wheels and the back ball caster to make sure our machine's body does not tilt, we decided on putting them on top, as you can see in the picture. Hopefully we don't have to change this later!

Meanwhile, we ordered new wheels a few weeks ago because we did not think the kit wheels provided enough friction. The wheels (pictured below) came in today, and they are 3.87" diameter, 1.95" thick, and made out of foam. The total price was $35.93 (tax + shipping included), but we think this was a smart way to spend some of our $100 allowance.

One aspect that we have to look at more is the material that we use to hold our axles. We believe the Aluminum 90 Degree Angle Stock (1"x1", 1/4" thick) will work, but we are going to talk to our GSI tomorrow to make sure that will work, and that we don't need another constraint for each axle. The 3D and orthographic views of our driving module are below.

Team Calendar

Here is our team's schedule for the rest of the semester:

http://goo.gl/8CrAa

Strategy and Design Concept

     Our strategy is to make a fast machine that first collects balls from the front edge of the table and then focuses on scoring balls from the perches of the tower. We are focusing on heavier balls due to the significant difference in mass between the ping pong balls (2.5g) and the squash and sand-filled squash balls (24g and 55g, respectively). Our concept has a non-motorized tray on the front of the machine that pushes the balls around the table. The tray has walls on the front and sides to prevent the balls from escaping. Additionally, there is an arm on top of the machine that is approximately 18” tall and has an L-shaped component attached to a torsion spring that is originally at 90˚ (due to initial size constraints). There is a rubber band attached to the wheel that pulls out a pin when the machine starts to move, making the spring expand to 180˚ and allowing us to reach both levels of the perches and knock off the balls. This machine would have two wheels at the front of the body for powering and steering, and one ball caster functioning as a wheel in the rear.

Pictures and sketches of the model are below:

This is the final machine sketch, with the arm at full extension

This is our physical sketch model with the arm at the original positioning. Note: the front tray design changed.