MotorCycle Box (Mechanical Model)
During this project, we were tasked to create a mechanical model that contained a mechanical mechanism, gearing system, contraption, or other assembly of mechanical parts. This project was meant to combine all of the skills we have already learned throughout the semester thus far, in order to create a functioning object.
During this design process we had to brainstorm what we wanted to create a physical representation of. After brainstorming and selecting an idea we went through a set of deliverables before reaching the conclusion of this project and submitting a final model with full integration, functionality, and deliberate aesthetics. These deliverables consisted of the three gates, Low Fidelity, Medium Fidelity, and High Fidelity Prototypes.
Throughout this project some of the design process we chose to use included: Laser Cutting, Waterjet Cutting, Vinyl Cutting, sandblasting, filing, sanding, painting, and using a multitude of handle tools to create our final design.
In our brainstorming and low fidelity phase we came up with the idea to create a box that allowed a motorcycle to have forward motion as the street below it also moved creating the effect that the motorcycle was driving on a street. We took inspiration from the 507 Mechanical Model to create these 3 translational motions. These were the two gear systems we were trying to replicate. Gear 1 would power the two moving streets and Gear 92 would be the mechanism that would translate the motorcycle forwards and backwards.
The mechanical movements we chose
This street would be placed at the top of the box and inside of the box would house all of our mechanical components that provided the external objects with our desired motion. In order to further visualize our idea we created an adobe illustrator file that consisted of a visual representation of both the look and function of our selected project design.
This images depicts our brainstormed idea as well as the functions of our moving parts.
After coming up with our idea we began to start on our low fidelity prototype. The materials included cardboard, wooden gears, small wooden dowels, hot glue, tape, and paper napkins. We were provided with cardboard and from there we began making the box. After cutting the pieces to the dimensions we wanted with a box cutter and creating the box exterior, we designed gears using a gear generator and then laser cut them out. We did the same thing with our motorcycle and some of the other parts within the interior. When all of our pieces were made we began to assemble our low fidelity prototype. This low fidelity model provided the visual image we wanted to convey along with the functionality. The road and the motorcycle system worked here!
Videos for low fidelity prototype: Video 1: Road & Video 2: motorcycle
These images show our low fidelity prototype. The first image has our more realistic motorcycle however it was too heavy to function so we created a second smaller motorcycle to show it intended function.
Moving on to our medium fidelity prototype we knew we wanted our box frame to be an airtight box with finger joints that didn’t use adhesives that way we could get inside of the box if we needed to. We used makercase to create our box template and then laser cut it out and assembled 3 pieces of the box together to allow us to make the parts that go in the inside without having trouble accessing them.
Above are the 3 faces of the box we assembled during our medium fidelity prototyping phase
For our medium fidelity prototype we made all of the pieces out of wood. This consisted of laser cutting our gears, the tracks in the inside of the box that allow the motorcycle to move back and forth, the circle pieces that allow the road to move, and other little pieces that assist in allowing our design to function. These laser cut pieces as well as wooden dowels sourced from the OEDK combined created our medium fidelity prototype. Our medium fidelity prototype once fully complete did function however there were some difficulties. The movement wasn’t smooth and kind of jolted back and forth instead of gliding.
Here are some of the laser cut parts from our medium fidelity prototype
On to the High Fidelity prototype which turned into our final prototype later on. We had to recut our box out on the laser cutter to account for the diameter of the bearings we used. This was an upgrade from our original medium fidelity prototype as it didn’t use bearings.
New laser cut piece which accounts for bearing
Some of the additional upgrades we made involved creating one side of the box out of acrylic in order to see all the mechanical systems inside. We additionally took the suggestion of combining the hand spinning of the road and the motorcycle into only one hand motion. To accomplish this, we brainstormed and researched many gear ratios given different diameter distances in order to spin the road and motorcycle for one single rotation by the user. After laser cutting various sizes of gears and testing it out on our medium fidelity model, we were confident in implementing it to our final fidelity.
We additionally opted for a metal interior rack that would hold the motorcycle track as we noticed high friction along the rail of two wooden pieces.
We upgraded our motorcycle design that was initially made out of cardboard to be made of acrylic and waterjet cut metal embellishments. The metal embellishments were very hard to accomplish as the design was so small and the pieces consistently floated away. However, after many trials, we learned that we can pause the cut, use some masking tape to hold the piece, and then remove after the section of cut
We additionally did several iterations of the road. We liked the texture of sandpaper but initially had made it double sided to cause friction with the felt gears. However, upon assembly, the double sided sandpaper was just too stiff to roll easily. Thus we went with a single piece of sandpaper spray painted.
For post processing, we sanded all the sides of the wooden box. Added an acrylic embellishment to look like a moon on the side with a vinyl cut of a city skyline to match the theme. We additionally painted the top of the box and pieces of the motorcycle.
Despite all these gates and progress, upon the final assembly, our gears for the road did not work and the motorcycle was too heavy to attach to the base of the track. Thus, in a rush for time, we tried to redesign a smaller gear to hopefully solve the problem, along with laser cutting a wooden 2D motorcycle to be attached to the track. Unfortunately, we were unable to see these solutions through given our deadline.
Final Product
Link to our presentation slide deck: https://docs.google.com/presentation/d/1EwBtxtHnWOos5NcdOVxOcaaJkWqWOBuf_rs8MPqndnc/edit?usp=sharing
STRENGTHS
Strengths of our project was our motorcycle design, laser cutting, waterjet cutting, vinyl cutting, and illustrator. Having really good illustrator files allowed us to perform our laser, waterjet, and vinyl cutting. When laser cutting we did pretty good because we had a well fitted box that was made from both wood and clear acrylic. The waterjet cutting in our project was good and performed its intended use therefor I consider this to be a strength of project. I was also excited about how our vinyl cutout came out and the placement of our vinyl on the box. Our application of using transfer paper to transfer our vinyl cutout on the box was a strength especially being my first time using transfer paper. Our motorcycle was also a huge strength of ours as well. It consisted of 3 different materials wood, acrylic, and metal which were all laser and waterjet cut.
Image of vinyl cut skyline and motorcycle
POINTS OF IMPROVEMENT
For this project there were many points of improvement that could be made. The main ones consist of functionality, post-processing, and part placement. Our biggest improvement that should be made in the future is functionality of our project. Our mechanism functioned sometimes in moving the motorcycle forward but didn’t truly allow for the street to move. Some of the reasons our project didn’t function was due to placement of our parts. Some things were too close together which caused friction and didn’t allow for our parts to freely move as intended. Next time, taking more time and providing more attention to placement would allow us to have a more fully functional project. As for the aesthetics in post-processing all we were able to post process was the metal components and the top of the box. We were able to sand the exterior of the box however we didn’t have the time or means to finish painting the exterior sides of the box. Although our metal components had been post-processed very nicely our overall project hadn’t been and that is something I would like to have improved on moving forward.
WHAT I LIKED ABOUT THIS PROJECT
I liked that this project allowed us to further gain experience on all of the tools we learned during the semester and giving us the freedom to do so on our own terms. I personally was able to gain more experience on the laser cutter, waterjet cutter, vinyl cutter, and with hand tools. I believe this project was definitely a learning experience. Although I am disappointed with the result I know that as an engineer and designer I am better now then where I started and have more experience that will allow me to excel in my engineering endeavors moving forward.
Problems Encountered
During this project there were quite a few problems that we encountered. One of the biggest hindrances was not being able to get access to the laser cutter often. The majority of all of our prototypes consisted of laser cut pieces and without being able to laser cut there wasn’t much that we could do. It was often hard to reserve it as people would reserve spots for 3 – 6 hours long. Another issue we had was when trying waterjet cut our designed pieces bed that we laid our metal on top of was overused so the little metal parts we tried to cut out sank to the bottom of the waterjet cutter and we couldn’t get the pieces we cut. This used up a lot of our reserved time on the waterjut cutter so we had to go back to try and cut out our parts on multiple occasions. Issues during our medium and high fidelity phases consisted of broken parts. We had quite a lot of pieces that broke or weren’t to the correct size so we had to try to remake those pieces but not easily having access to the laser cutter prevented these broken pieces from being an easy fix. A lot of the time when something broke or messed up we had to adapt and come up with a second hand solution to resolving the problem. These resolutions weren’t always the most optimal and it showed in our final results. We also weren’t able to spray paint using the colors and paint we initially wanted because other groups had used it all up and there was no more at the OEDK. After wasting some time trying navigate ways we could paint or project Emily came up with the solutions to bring her own personal paints which we were able to use but only on the top of our box and not on the entire project.Another problem we encountered was scheduling conflicts, which was something I didn’t think would affect us much but ended up playing a larger role than I assumed. A lot of the time my partner and I couldn’t meet up at the same time due to scheduling conflicts and had to go to the OEDK to work on parts of the project individually. This led to disconnect at some parts of the project and didn’t allow us to work as effectively as we could’ve had we been able to meet together more often and for longer periods of time. Overall these problems led to us not being able to create the masterpiece we truly envisioned at the start of this project and we had to submit what we were able to complete at the time.
WHAT I WOULD I DO DIFFERENTLY
When looking back on the project I believe we might have been a bit overly ambitious. There were times during the project where we would want to add new features and try new things but doing this actually set us back. Given the opportunity again I feel like we would’ve seen more success had we stuck with our original plan or if we simplified our plan once we first started running into difficulties in order to allow us to submit a well rounded project that was fully functional and aesthetically pleasing.
Cost Analysis: (All from HomeDepot Website)
1/2 in Raw Round Dowel 88¢ eachx3= $2.64
1/4 in. x 2 ft. x 2 ft. Sanded Plywood $7.28×4= $29.12
0.6693 in. Steel Plain Precision Bearing and Reducer $4.75 each)x5= : $21.25
Stainless Steel Sheet Metal for 1′ x 2′ :$39.60
Elmer Carpenter Wood Glue $2.88 each: $2.88
12 in. x 24 in. x 1/8 in. Thick Acrylic Clear Sheet $15.33
12 in. x 24 in. x 1/8 in. Thick Acrylic Black Opaque Sheet $16.14
0.85 fl. oz. Epoxy $7.48
Labor: 30 hrs x $15 an hour: $450
Total: $584.44
