Final Post

ME 250 has taught me a lot about the overall design and manufacturing process. Coming into this class, the only design experience I had had been the CAD classes I had taken in high school and my ENGR 101 course. In the past I would have maybe come up with rough CAD drawing, devoid of any details, and used it as a guideline, adjusting the design on the fly, then make a final drawing that matches what we built. However, this project was the first where I've been part of a team that actually developed working plans, and the proceed to make custom parts, rather than gerry-rigging pre-made components to make a passable machine. This was the first time I have focused on often overlooked parts like screws and bushings. I learned how important it is design for these, and how big a difference they can make.

Once we got out of the design phase, I learned an entirely different set of skills. Before this class, my manufacturing skills were limited to use of the band saw and drill press. Now I can say that I am capable of using a mill, lathe, and laser cutter. As a team, I feel like we did a good job of playing towards our strengths. Once we each settled into our roles, we got our work done quite efficiently. Teamwork was critical to this process, each of us had to rely on the others in order for us to finish on time. Had the CAD, or the manufacturing, or assembly lagged, we may not have had completed our machine. Even when we did suffer some sort of setback, we worked as a team to get through it, by putting in extra time out of class or in the shop.

This class gave me a better sense of how much time it takes to design and build a working machine. This was clearly not something that we could not have procrastinate on. We had to work around scheduling conflicts and shop times, we managed to get all of our work done and find time when it counted, like the Monday before the competition when our motor were not working and our couplings didn't work. We found the time to re-solder the motors and fix our coupling shafts. In the end we manage to get everything together and do well in the scoring round.

I think the course is well put together. I thought that the progression made a lot of sense though I would have liked to move the time line up slightly in order to get more manufacturing time. I found that the amount of time we got to actually build, test, and adjust our machine was very limited, it would have been nice to work out more of the kinks before the competition. This might of allowed us to remake certain components which we may have discovered could have been made better. I also think it may have helped me if we had more CAD labs, although I already knew Autocad, I would have liked to have had more experience with Solidworks.

FInal Post

ME 250 really changed my view on the manufacturing process. In any previous project-based class or endeavor I undertook I would typically get a general idea of what was to be built and then begin building. This would then result in an extremely inefficient building process, wasted materials, and usually an extremely sub-par result. This would then have to be redesigned and rebuilt to get an end product of desired quality. In ME 250 we spent the vast majority of the semester designing the machine, making a CAD model, and tweaking the design. We then spent about 2 weeks or so actually building the machine and the end result worked astonishingly well. This really taught me how much more important the design stage is than the building stage and how the design stage can really be broken down into many parts starting from broad strategies down to individual components of your final design. I also learned how every detail of your design affects multiple different functional requirements for your final product and how you can analyze these kinds of things using a simple pugh chart.

Overall my team was fairly well organized which helped us to stay on track with our goals in the class. We also got along very well with each other, which was a huge advantage and taught me a lot about teamwork. What really makes a good team though is not only a group of people who work well together, but a diverse team as well. People will obviously do the best job at something that they like to do and are hopefully good at. So if your team is diverse enough then you can simply let everyone do the tasks they want to do and just help out with the other tasks. This results in everything being done well and it helps everyone to learn from each other. Also, if your team is diverse in leadership and or management abilities than you will do much better than a team with 4 dominant leaders or vise versa. Therefore it is very important that people begin to understand where they can fit in best in the group and to take on that role whether or not it is their most dominant strategy for team management. Most people at least somewhat have the ability to play several different roles in a team and it is important that all of these roles are fulfilled including the leader, analyst, promoter and supporter.

In the future I believe that ME 250 should have more CAD labs. Although I did gain a basic understanding of SolidWorks, I did not even come close to becoming proficient in the program. This is a valuable skill and has huge potential if mastered, but takes a lot of time and practice. Also, I was surprised that we did not have to complete a more extensive final report and reflection on the class. Although I did learn a lot from the reflection I am currently writing I think that there were more overall ideas that could have been taken from the course that I may be missing. This probably could have been emphasized more. I would also of greatly appreciated more mill times during the final weeks. This would of helped us to finish earlier and make a better machine.

Simply put I could have improved my performance by putting more time into the class. Although I don’t think it was absolutely necessary I am sure that if we had completed our machine a few days earlier we would of done better in the competition. We would have had more time to fix problems and master the control system. However, the rest of the class was in the same time constraint as our team, which leveled the playing field and actually helped us because of the simplicity in our design.

Final project/Competition

We finished our machine in time for the time trial. We ended up having to modify very little on own final project when compared to the CAD model. This was very good for us because it cut down on the assembly and designing time, allowing us to get the project done. We had some trouble with breaking taps inside of the milled holes. This was because we used a lot of screw holes and we used really small screw holes. Whenever one of these broke we would have to re-make the part, this obviously makes the assembly time go up.



We did very well in the time trial scoring 96 points. This was less then we predicted earlier in the year when we calculated our expected score. But this score was good enough to get us seeded 3rd for the actual tournament. At the tournament our machine did very well in the first round winning it pretty easily. In the second round we started out well, but had a driving error and fell into our own hole. The other team barley had enough time to score as much as we did in the first few seconds. This was very unfortunate because we felt that we could have done much better in the tournament. However we felt that the project was a success because we did well compared to other teams.
                   

                                                                               Bill of Materials

Item #	Description	Use	Dimensions (in)	Supplier	Qty	Material	$ Price
1	Top	Top of frame	1/4 x 12 x 18	kit	1	Acrylic	12.07
2	Arm 1, Arm 2	Arms	1/16 x 1.6 x 10	kit	2	Alum 6061	1.2
3	Base Side, Base Side 2	Sides of frame	1/4 x 1.6 x 5.25	kit	2	Alum 6061	2.16
4	Base Back	Back of frame	1/4 x 1.6 x 9	kit	1	Alum 6061	1.84
5	Base Round	Inner round frame	1/16 x 1.6 x 14	kit	1	Alum 6061	0.84
6	Wheels	Wheels	5(r) x 1(w)	McMaster	2	Rubber	5.5
7	Double Gearbox	Drive wheels	2.75 x 2.25	kit	1	Plastic	8.75
8	Shaft mount	Support Axle	1/4 x 1 x 1	kit	4	Alum 6061	1.66
9	Coupling Shaft	Drive axle	.84 x 3/8	kit	2	Alum 6061	0.22
10	Crossbar	Support frame	1/4 x 1/2 x 8.5	kit	1	Alum 6061	0.16
11	#6-32 Screws	Drive train to top	1/4	crib	10	SS
12	#4-40 Scews	Control box to base	1/4	crib	2	SS
13	#4-40 Scews flat head	Base Round to frame	1/2	crib	11	SS
13	#4-40 Scews	Top to crossbar	3/8	crib	2	SS
14	#4-40 Scews	Scoop to Scoop Arm	3/8	crib	8	SS
15	#4-40 Scews	Top to Base	1/2	crib	17	SS
16	#4-40 Scews	Scoop Mount to top	3/8	crib	4	SS
17	#4-40 Set Screw	Coupling shaft	1/4	crib	2	SS
18	Wheel Axle	Drive wheels	4x0.375	kit	2	Alum 6061	2.16
19	Axle to Motor Connector	Drive axle	3/8	kit	2	Plastic
20	Bearings	Support axle	3/8	McMaster	4	SS	2.44
21	Control Box Holder	Control box holder	1/16 x 3 x 6	kit	1	Alum 6061	0.68
22	Control Box	Control motor	2 x 5	kit	1	Plastic
23	Shovel Arm	Scoop Assembly	4 x .5	kit	2	Delrin	0.24
24	L Bracket	Scoop Assembly	1 X .5 x 1/16	kit	2	Alum 6061	0.04
25	Scoop	Scoop Assembly	15 X 2 x 1/8	kit	1	Delrin	1.86
26	Shovel Axle	Scoop Assembly	6 X .25	kit	1	Alum 6061	0.19
27	Gear	Scoop Ax to Plnt Box	1 x 1	kit	2	Plastic	2.66
28	Gearbox Assy.	Planatary Gearbox	4 x 2 x 2	kit	1	Plastic	14.25
29	Scoop Axle Mount	G-box/Scoop to top	.25 x 1 x .75	kit	3	Alum 6061	0.93
30	Planatary Couple	Plnt Box to Axle	1.5 x .25	kit	1	Alum 6061
31	Scoop Bushing	For Scoop Axle Mnt	.5 *.25	kit	3	SS	1.29
							Total: $61.14