October 31st Update

Figure 1. Shoe design idea

On Wednesday, October 23rd, we had our team presentation. This presentation went very well. The reason for our success this time around was due to our extra preparation. The Saturday before, we completed over 90% of the presentation and we practiced until the day of the presentation. We also assigned the slides to each presenter on Saturday so each person knew exactly what they would cover. A cardboard aided design of our shoe idea was made by Melody (Figure 1).

On Friday, October 25th, the team spoke with Mersen. They supply custom design conductor shoes. However, they are not a good option for us because each shoe is $200. On Monday, October 28th,
the team contacted Helwig. We got a good response from them and so we will keep in contact with them. Both companies mentioned three-phase systems. We wonder if they're using an AC system on their Wayside. Additionally, VTA was contacted and they use bronze shoes and that is the reason it is so loud/noisy. We will be using graphite shoes.

Additionally, Shane and Alex will be attending the Pod Car City event on Monday to speak with VTA. Alex will represent our team on Wednesday by briefly explaining what our team is doing for Superway. Melody will be on a panel on Wednesday representing Spartan Superway.

Written by,
Aryamitra Bake (Melody)

Presentation 2

This past week we met on Saturday and a smaller group on Tuesday. On Saturday, we delegated topics for the coming presentation on 10/23. Shane would concentrate on the shoe design that we collectively decided on. The shoe would be split into three contacts. Splitting the contact into segments like this would provide constant contact with the rail even thought there are obstacles on the rail. Each segment would go over the obstacle as the other two would remain on the rail. Alex described that a pantograph would not be easily incorporated the suspended railway but a third rail would be easier to maintain and integrate with a bogie. He also analyzed the problem with using a carbon brush for our shoe. Carbon is extremely brittle which would be very problematic in high speed and stress situations. Reynaldo created a CAD sketch of a segment of our theoretical third rail. It had the framework of insulation, protective rail hood, rail, shoe and shoe mechanism, and bogie. Melody presented the summary and purpose of our team. We must streamline this introduction for third parties to understand the mission of our organization. She also constructively produced an invaluable Cardboard Aided Design of our conductor shoe. It was made of cardboard, wires, glue, and spray paint. I was in charge of the theoretical analysis of our designs. The resistivity of steel and aluminum are well within the electrical demands that we will expect. I generalized our specifications to add a safe factor that would accommodate most real world inconsistencies. Below is a link to our presentation.

https://docs.google.com/presentation/d/1Hw5b9X9rM5GM9XjI1S0V5aNhWNOV-m1YxU_WJBn2jbI/edit?usp=sharing

Patent Research and CAD

Research

This week our team conducted research on patents of existing designs for the conductor shoe mechanism. We used google scholar to look up these patents and we found numerous designs that are influencing our work. The group decided to include multiple conductor shoes in the mechanism with springs. This will provide a way to overcome imperfections or rail to rail transitions. An image from patent US2013/0213754A1 is shown below that may influence our design.

Figure 1. Multiple conductor shoe with springs. US patent 0213754A1

Further research was done with the power supply. The team decided that we need to provide a and supercapacitor reserve pack so the system can be charged faster. To better understand how the power system is going to be designed, we made an outline shown below in figure 2.

Figure 2. Electrical design sketch. 

Reynaldo made some CAD designs for a rapid prototype of the third rail shown in figure 3 shown below. We are including a safety shield to block anyone from touching the high voltage rail.

Figure 3. Design of small scale track and power rail. 

Problems

We are still working on how to keep the conductor shoe forced onto the rail. Four bar mechanisms with a spring would be the easiest or using a torsional spring to provide downforce on the rail. We are considering some kind of linear actuator or solenoid, but those designs may infer design complications.
Additionally, getting the whole team together at the same time to work on our project has been difficult. Everyone in the team has a different course load and different schedules.

Meeting with Power Module Team

Figure 1, Rapid Prototype Flowchart

We are having our weekly meeting on October 6th. The team are meeting at usual time from 4 pm to 7 pm. This time, we are also have a meeting with Steven from Power Module Team.
After having a discussion with power module team, both of the team decided that power module team will be reducing supercap numbers. We also determine to have ⅕ scale for rapid prototype. Then we make a flow chart for our Rapid Prototype. (Figure 1). We also reconsider our shoe arm mechanism on our discussion. (Figure 2)

Figure 2, Our design consideration for Shoe Arm Mechanism

Over the weeks, we also have a meeting with other people.
On Tuesday, October 8th, the team have a short meeting with Hussain, who will help us with the charging system. and we decided to ask him to join us on our next week meeting.
On Wednesday, October 9th, we also have a meeting with Tynan from last year Wayside and Power Module Team. We spent our time discussing about potential improvement for our wayside team.

Written by,
Reynaldo Jahja

Figure 1. Pros and cons list of various contact shoe designs.

On Sunday, September 29th, the team met and covered a good amount of work. Each member documented their busy weeks for the Fall semester so that the workload can be distributed accordingly. Most of the time was spent on determining the third rail, shoe, and arm mechanism designs. A pors and cons list (figure 1) was made comparing the top, bottom, and side contact shoe designs (figure 2).

Figure 2. Top, bottom, side contact shoe designs.

It was decided that the Wayside team will implement a top contact for various reasons:

• gravity is acting in our favor
• top contact shoes are more abundant in the market
• has the most fail-safe options in comparison to other designs.
• easier to account for vibrations
• most flexibility

Figure 3. Sketch of third rail, arm mechanism, and contact shoe

Figure 3 shows a sketch that the team drew of the third rail, arm mechanism, and the contact shoe. In red are the solar panel and the safety side-walls. In green is the insulation. Figure 4 shows a CAD isometric design.

Figure 4. Isometric view of third rail and
the solar panels and side walls. 

On Thursday, October 2nd, different shoe materials were considered. Carbon graphite is a solid dry lubricant meaning that it slides easily and it would make sense to use it while the bogie is in motion. It was mentioned that copper has a lower resistivity and is less durable when compared to carbon graphite. A copper shoe could be used to more rapidly charge the bogie while it is stationary. The team will start thinking about whether it would make sense to implement both a copper and carbon graphite shoe in the design.

Additionally, the Wayside team consulted with the Power team twice this week to discuss charging and power distribution.

Written by,
Aryamtira Bake (Melody)