week 15: update and finals week

Update from team member Kevin that there is no need for us to manufacture the strip for positioning team.

No word were put in to the Spartan Superway due to the upcoming final exams.

week 14: Presentation

This week we focused fully on the final presentation and tried to meet every specification of the rubric.

presentation 3:

Week 13 final report and resentation

Thanks giving week, family gathering, and little progress on the bender.
This week we focused on generating the final presentation and the 1st draft of final report.

The report was fairly long and time consuming so extra work will be done after finishing the report.

Week 12 updates

Update to the bender,
What is created:

• 2 dies for 2 different radii
• metal arm for bending
• Bending table
• support block
• one measuring block
• roller/caster

They will be assembled to perform the bending. from the testing, every thing looks successful so far except the die for bending the 1/4 in aluminum bar needs to be refined so we don't have to band the flat stock several times to complete one curve. 

week 11 die switching mechanism

This week me in and I couldn't manage a time to meet, so I stayed home and did some design on the quick die-switching mechanism since the bender is being built at his house. I did some research about expandable die, similar to a transforming table where it transforms from a small circle to a larger circle. This mechanism require extreme precision and internal design. So what I think is most suitable is to make multiple dies with different desired redii and develop a quick switching mechanism to quickly switch out different dies so the future bending and testing can be done easily. Below is some sketches of the design.

Week 10: individual writing assignment #2 and plotting 1:1 scaled drawing.

The second individual writing assignment is due this week on 11/9/2016. I worked on that as well as the plotting the actual curve onto multiple pieces of paper.

From previous week, i confirmed that the intended curve radius from last year was 20". After some research on how plot 1:1 drawing, I used Sketchup to make the drawing and export it as a PDF file. then use adobe PDF reader to print the drawing as a poster in Sketchup does not allow me to print with multiple paper.

Result was successful:

Week 9 - measurement of previous team's product

I measured the curved aluminum of the 3 corners of the track. the forth corner is missing so theres no data from it. I measured it using a compass and a ruler. I took 3 measurements from each bent aluminum and averaged them. Aluminum#2 and 3 is somewhat consistent but aluminum number 1 had a reading of 22.625" radius that is not acceptable. I assumed that the previous team did not have a consistent machine that do the bending.

Week 8 : Presentation #2

This week we prepared our second presentation.

The presentation includes a new design of aluminum bender.

We calculated several numbers towards the design including force required and shear stress act on the bolts, and spring back effect of the aluminum.

If this bender design works out well, we should expect fabrication to start early next semester.

Week 7: Gathering numbers

This week I looked into the measurements from previous year's design and tried to compare it with the actual tracks they made. We wanted to see what challenges they faced so we will get an idea of what needs to be focused while fabricating.

We are yet to get access to the school machine shop E123, hopefully it will come down during the following days.


measurements :

week 6

This week we decided that our original bender design will be thrown out, and we will use a Hossfeld bender instead which is available in the local tech shop. However i was informed that the tech shop will only be available for one month so that is not going to work. we also contacted Lilly, and she said that the door code for E123 should arrive in a week. I hope that it will get us started on fabricating, otherwise, we will pay for the tech shop membership or classes or whatever is needed in order for us to get into the techshop.

On the otherside, since designing a bender is not a concern anymore, we will start getting informations and numbers about the tracks and bend radius, etc. The main method for us to ben the aluminum strips will be having a 1:1 CAD drawing printed out and ben the aluminum by hand accordingly.

week 5

This week's meeting is the first presentation of the half scale group. I had a good understanding of what they are doing although it is almost completely different from our 12th scale model.

Door request code is still pending. So we couldn't have access to E123 and play around with the machines. 

week 4

This week we worked on our first presentation. We gathered information about bending aluminum strips including different methods and different machines. the machines are around $1000 so we desided to use existing tools to create a method. we took pictures of the current track issue and put it on the presentation. We also requested for the E123 door code and are waiting for Lilly's respond.

week 3

This week we continued to work on identifying the issues of the previous tracks and see what part needs to be changed or improved. We also communicated with all the small scale teams and we created a group in Slack, which is a online communication App, for easier communication in the future. Everyone was cleared that by the end of the school year, we need 4 loops of track and have at least 5 bogie running simultaneously.

We identified the problem of the tracks with track improvement team and had a conclusion that the second loop needed to be rebuilt because it was poorly manufactured.

Kevin emailed Lilly, who is the administrator of the mechanical engineering department, to get access of room E123 which is the tech shop. Once we get access to E123, we will start getting hands on experience with bending aluminum and see what methods we can use to make each bent uniform.

9/7/2016

              On 9/7/2016, my partner and I looked at the previous work of the track and understood the problem that the previous manufacturing team had faced. We found that the main problem was that the radii of the curved aluminum at the four corners of the track were not equally shaped which makes the bogie stuck or fall during the test run.

              We noted down key information such as where the previous team bent the aluminum, what machines they used and what company they contacted. We talked to Dr. Furman and got some useful contact information that we can ask for help.

              Our next step is to contact these people and companies provided by Dr. Furman to get more information about how the aluminum should be worked. After this, we will either get in touch with the track improvement team and see how they design the tracks, or try to get the tracks from previous semester back to work.   

Previous Experiences on Mechine design project

Shengosng Cho
8/30/2016



In ME154, we formed a group of four people, and we designed a machine that would automatically walk to the middle of the road and raise up a stop sign when it senses people crossing the road. The project mainly was divided into 6 parts: linkage system design, force analysis, sensor design, the machine’s body design, the prototype manufacturing, and product testing. I was involved in most of them except sensor design because one of the team members who was taking Mechatronics took care of it. During the machine design process and the prototype making process, I experienced success and failure.

In the linkage design, we successfully designed a 4-bar linkage for our machine using skills we learned in ME154. Then it comes to the force analysis of the links. I failed because I made a bad assumption on the weight of the stop sign resulting a large needed torque on the crank (driver link). I went back and corrected the weight of the stop sign after some researches, and the resulting torque was then approved by the professor. After force analysis, we were to design the body of the machine, it had to be stable enough to be one the road and not too heavy so the motor was able to move the machine. We came up with a design using wood sheets and wood rods, and the design was successful.

The manufacturing process was a fun part. First, we drew out all the parts on the wood sheets and started cutting using machine saw. One part of the process which I experienced failure was that I could not cut the wooden rods perpendicularly, therefore it would not stand on its own. I brought the rods into the ME41 (machine shop Lab) and asked the instructor for help. He introduced me another cutting saw which did the job. Then I used machine drill to put the parts together with screws and bolts. Overall, the manufacturing was successful.

The final part comes to product testing. Our motor which ran the 4-bar linkage had no problem. However, the motor which ran the wheels was not strong enough to move the machine. We went and bought another motor and made it a 4-wheel drive. After we put in the motor, the machine worked like a charm.

Link of the final prototype:

https://www.youtube.com/watch?v=JQ6WyxWmHBw

In this machine design experience, I learned how to work as a team, how to use machine drills and saws, and how to make assumptions after doing researches. Hopefully the experiences will help me in the Spartan Superway project.