Monday, December 10, 2012

Final Reflection: Jess Costantini



Completing ME 250 this semester has taught me about designing, manufacturing, teamwork and time management.

During the design process, I have learned to keep in mind the limits of a project, such as available materials, manufacturing ability and time. All four of my team members and I were new to manufacturing, a factor that played a large role in the design of our machine. In order to design a machine that minimized input and maximized output of these three and other qualities, we tried for simplicity. If there were one thing I would wish to take away from this class, it would be that simple is better.

I came into this ME 250 class with little exposure to manufacturing processes. Learning to use the mill, drill press and other basic handheld tools was both interesting and a little intimidating at first. After a while though, it was gratifying to be able to make a connection between a part on paper and the correct machining method to yield a finished part in 3D. From carrying out these machining processes, I also learned the importance of double, triple checking everything. We had several bad moments when our parts didn’t fit exactly how we needed them to and resulted in time lost from our already chaotic schedule. For example, the aluminum base plate (which catches the lip of the restraint tubing as it slides down in the restraint housing to keep the anchor from slipping through our machine completely) was just a smidgen too small for the restraint to slide through. We spent well over an hour filing it down to the correct size.

A large part of teamwork is communication. Something I learned about communicating with my team in ME 250 and something I personally had an issue with was the importance of being assertive. I believe this is what I would change about my performance in this class. I found, especially in a class that requires such varied work (CAD models, manufacturing, blogging, etc.), that splitting the workload in terms of peoples’ strengths was helpful. I also learned the benefit of preparing for a meeting ahead of time. The more prepared we were individually, the more efficient our meetings became. Later on, as our team utilized sources such as Google Docs our efficiency increased even more.

The one change I would suggest for this course is more emphasis on manufacturing early. By the time our team realized the nearness of the due date and began serious manufacture mode the machine shop was swamped, whereas the previous week there had been machines open. Otherwise the GSI’s, instructors and machine shop instructors did a great job of preparing us for the class.

My experience in ME 250 was enjoyable. Although the class was a great deal of work and put me through a steep learning curve, the majority of what I learned will be of great use in the future. It will be interesting to see what ME 350 and 450 have in store.

-Jess

Final Blog Post


We completed our machine this past week just before the Balltower Competition. In the competition we made it past the first round, but unfortunately we lost to team Holy Moly in the next round for a spot in the Quarterfinals.
Our final machine turned out very similar to our solid model (shown below). Only minor details were changed due to unforeseen obstacles in the manufacturing stages. For example, we didn't anticipate any difficulties in manufacturing our pincers with the curved shape we had planned while designing our machine. However, after working in the machine shop we gained a better grasp of our manufacturing limitations. We found that it would be much easier to create two identical pincers by bending our sheet aluminum at 45 and 90 degree angles, instead of attempted to give them a curved shape.
Our final machine also turned out to be very robust and very quick. Bracket placement in our machine proved to be very effective at giving it a high level of rigidity and stability. The fact that our machine turned out to be very quick was surprising to us because it is a relatively heavy machine, but the high gear ratio that we used for our double gearbox gave it enough speed to overshadow its weight.

Also, our deployable anchor system turned out pretty good. We had a small problem in fitting the aluminum plate into the system but eventually we figured it out. Also, when we cut the pin connected to planetary gearbox shorter, we achieved to a better result.  

One of the most annoying problems we had was about the soldering of the connection wires of the motors.  Since we haven’t had perfect soldering, the machine randomly stopped on the table, but fortunately we didn’t encounter such a problem in Balltower Contest.

Final Bill of Materials:






#
Description
Use
Dimensions
Supplier
price
1
Brackets
General assembly
1.5" x 1.5"
Stadium Hardware
6
2
Rubber wheels
-
4" diameter, 5/16" bore
Advance Caster & Wheel Company
11.34
3
Aluminum Tubing
Restraint
3" long (3" OD, 2.75 ID), 3" long (2.75" OD, 2.25" ID)
Online Metals
26
4
Wheels
Wheels
4" diameter
Marketplace
16
5
1/4" Acrylic plate
Base Plate
12"x18"
Kit
-
6
Aluminum plate, 1/16" thick
Pincers, Support Plate
12"x18"
Kit
-
7
Architectural Aluminum Tube (Alloy 6063) Square, 2" X 1", 1/8" Wall
Side Chassie
18"
Kit
-
8
Aluminum 90 Degree Angle Stock - 1"x1"x6', 1/4" thick
Brackets
18"
Kit
-
9
Steel shaft, 1/4" diameter, tool steel type "O2"
Axles
12"
Kit
-
10
Flanged SS bearing - 1/4" ID, 1/2" OD, 1/8" Thick
Bearings
-
Kit
-
11
Flanged brass bushing - 1/4" ID, 3/8" OD
Bearings
-
Kit
-
12
E-Clip retaining rings - 3/8" Dia.
-
Kit
-
13
1" ball caster
Back Wheels
-
Kit
-
14
Tamiya 72001 Planetary Gearbox Kit (includes motor)
Restraint Release Motor
-
Kit
-
15
Tamiya 70168 Double Gearbox Kit (includes 2 motors)
Axle Motor
-
Kit
-
16
Wire
Motor Connector
-
Kit
-
17
Electrical connectors, male quick disconnect
-
-
Kit
-
18
Adhesive Velcro, 1.2 pull-apart, 200 cycles, 1" wide 0.188" thick
Control Box Connector
8"
Kit
-
19
Stock fasteners (screws, washers, bolts, nuts)
General Assembly
-
Kit
-
20
Kevlar Thread - 300yd, 28lb Tensile, 0.014" Dia.
Release Mechanism
5"
Kit
-
21
1/4" Baltic Birch Plywood
Restraint Bottom
12"x24"
Kit
-



Final Machine:
Final CAD:






~Pimp My Ride

Sunday, December 9, 2012

Final Reflection: Yagiz Yildiz


I can say that this class was a really different and learning experience for me. I had a great experience about working as a team and designing something from the beginning. Even though I am not going to be a Mechanical Engineer and I took this class as a Technical Elective, I liked it a lot. I think, thanks to ME 250 I got an insight about design and manufacturing process, which will definitely make me a better engineer.

The most important thing I learned from this class is that having correct measurements is the most important thing in a design. If the different parts that you manufactured don’t fit each other you won’t have a fully functioning machine. Having correct measurements and perfect parts that fits each other depends on the preparations you made before the manufacturing process.  Now that we got our grades from the machines, I can admit that some of the parts we manufactured had slightly wrong dimensions, fortunately we figured the problems out and made them fit each other but at the end of the day we understood that for our next design we should be a lot more careful while dimensioning different parts.

The other thing I can talk about is scheduling and timing. While working as a team, you cannot always find a time that works for each member and this eventually slows the team down. If your team can’t manage its time carefully you will end up with last minute actions. Hopefully, we didn’t have a major scheduling or timing problems but I can say that we could have done even better.

Working as a team is important because in this way you can divide the job among the members and this makes everything easier if everybody does his or her part in time. Also, each person has his or her different ideas and point of view that is why by teamwork you can always arrive to a better solution in shorter time.

Also, I should say that I have never used a lathe or mill in my life before I absolutely enjoyed learning and using it.  By using the machines on my own and seeing problems that can be faced during process, I understood the importance of having a simple and clean design. Sometimes you design a product without think about the manufacturing process. Thanks to this class, I’ll always have some basic idea about the feasibility of the product.

In additions, driving the machine that I contributed to design and manufacture, was so much fun and priceless. See you product in real life and seeing how that products interacts with the environment taught me a lot about the design and manufacturing process.

In opinion, one thing that needs to be changed in this class is the schedule. I think teams need more time for MS8, MS9 and MS10. We spent decent amount of time for planning and designing but we didn’t have enough time to manufacture our machine properly. We were always in a rush and we had hard times solving the problems we encountered during the manufacturing process.

Other than that, GSIs and teachers were extremely helpful about everything.  I think lectures were really interesting and they actually taught a lot about the design process.

Saturday, December 8, 2012

Final Reflection: Dan Hiemstra


My semester in ME250 was overall a good experience that taught me a lot about both engineering and teamwork. Although the road wasn't always smooth, I learned a great deal from this course. It was an awesome way to get hands on experience with mechanical engineering, something that we have only talked about so far. It provided a vehicle to get from being told how things work to seeing how things work.

The most challenging part of the course for me was trying to coordinate the group as the team leader. I learned how much time, initiative, and organization it takes to coordinate between multiple people. By the end of the semester I became more organized with expectations and goals, and I think it paid off. I think looking back at it I could have done a better job; however, I am satisfied with how the semester turned out. This was my first time leading a small group, so have taken a lot away from it.

In addition to practical manufacturing skills (Mill, Lathe, etc.), I learned a lot about workflow. The first few times in the shop, it took several hours to complete only a few parts. By the end of the manufacturing process, I was much more comfortable with tools, their uses, and how to use them efficiently. This lead to much faster manufacturing times.

Another thing I learned was how much it pays off to double (and triple, and quadruple) check each aspect of your design. We were set back multiple times because of slight errors in measurements, or lack of details in the CAD that lead to problems during assembly. If I did the semester over, I would be sure to thoroughly check over every part and assembly to make sure they worked. A little time spent on the front end can save much much more time on the back end.

For me, the most enjoyable part of the course was driving our machine after we had finished. After planning it all semester, tweaking CAD models, remaking wrong parts, trying to get the motors to work, and countless other things, being able to drive the machine around was very gratifying. Having a tangible machine that matches the CAD model was awesome. It was a great experience following our idea from conception, through each design and manufacturing step, all the way to completion.

Overall, I think the course was run well. The GSI's and professors were very helpful. One thing that I would change would be to either give more time for manufacturing, or more clearly emphasize the need to have everything finalized by the time the machine shop opened to us. I don’t think we were the only group that MS8 and MS9 snuck up on. Overall, manufacturing seemed very rushed. I think our machine would have turned out even better if we had more time to put into each part. That being said, it may not be possible to allocate more time on the manufacturing end, but it is just a thought.  

-Dan

All done!

Tuesday, December 4, 2012

Manufacturing: Restraint Pin

Hey guys,

Today we finished the last and final part of our restraint manufacturing and assembly: the pin. This pin allows the planetary gearbox to pull it out, releasing the restraint.

The first picture shows the original pin length, and the planetary motor assembly.

We bought a stock aluminum pin from a hardware store, then cut it down to less than an inch in length. This allowed it to be just long enough to fit through both the restraint and the restraint housing.
To allow the planetary assembly to retract the pin, we first attached a brass coupling off the end of the motor. We then attached Kevlar yarn through the pin and around the brass coupling. When the planetary motor spins, it winds the yarn up and retracts the pin, releasing the restraint.

We had some troubleshooting uses with the control box, as the motor would not always spin. We have fixed it (hopefully) and it works really well.

-Dan

Deployable Anchor and Housing Update

This past week we completed the manufacturing and assembly of our deployable anchor and anchor housing. We used the laser cutter to manufacture the anchor bottom plates from plywood we recieved in our project kit. The picture below shows the laser cutter as it cuts out our anchor bottom.





The two pieces of Round Aluminum Tube Stock that we purchased were used to make the bodies of our deployable anchor and housing. We used the lathe to remove material from the outer surface of the smaller diameter tube stock to create its lip, and also used the the lathe to cut the tube stock down to the length we needed.

The holes in the anchor and housing were drilled using the mill. We accurately drilled the two pairs of holes on the deployable anchor perpendicular to each other by placing another quarter inch drill bit in the pair of holes that had been drilled first, and setting this drill bit on the vice to ensure that it was being clamped perpendicular to the already drilled pair of holes.

Finished Anchor and Housing
 
                                                                      Anchor Bottom Plate