Power Team Update

So far we have discussed a few design iterations for the wayside rail on both the 1/12 scale model and the 1/4 scale model. The 1/12 scale model is the priority right now because the 1/4 scale has not begun construction where the 1/12 scale is already built and ready for a wayside rail. The team is much more organized than it was two weeks ago. We now have a Gantt chart, a google group, and a list of contact information. Other than that, we all are going to bring new design iterations to our next session, on Wednesday 9/23.

Electric Wayside Pickup Proposal

ME 195A

Electric Wayside Pickup

Proposal

Team members, with brief listing of pertinent skills and responsibilities

Name	Skills	Email	Responsibilities
Garrett Gemmel	Electrical contracting, Solidworks, AutoCAD	GGemmel777@gmail.com	Project Management, CAD Design
Michael Hurst	Video Production / Mechatronics / Solidworks / Reports Writing	michael.p.hurst@gmail.com	Write reports, prepare materials for team presentations, research available solutions and communicate with suppliers, assist in fabrication of scale wayside power, assist in CAD modelling of designs.
Dianna Man	AutoCad, Inventor,Thermal/Fluids, Machining, Matlab	mandianna10@gmail.com	Budgeting, Design/CAD, Fabrication, Testing
Karmjot Singh	AutoCAD, Inventor, Machining, MatLab, Arduino	singh.karmjot@gmail.com	Design/CAD, Testing, Fabrication, Integration and Analysis, Scheduling
Matt Holst	Electrical Engineer	mattholst33@gmail.com	Coordinate efforts between EE team and Wayside Power team
Nasrat Haidari	AutoCad, Machining, Analysis, circuits, matlab, and micoprocessor programming	haidarinasrat@gmail.com	Design/CAD, Circuit analysis, testing, Scheduling, Integration, fabrication, and editing

Proposal narrative

The wayside power team will design a working model for the 1/12 and ¼ scale and will collaborate with the solar and bogie teams to determine the best method of powering our bogies with solar.

Design Requirements

• Hot rail on 1/12 and ¼ scale models to be kid safe for Maker Faire
• Power supply and circuitry to power up to 10 bogies on the 1/12 scale and up to 10 bogies on the ¼ scale
• Aesthetically pleasing and durable implementation of wayside power
• Stationary source

Deliverables

• Working model for wayside power on 1/12 and ¼ scale

Things to Accomplish (Action Items)

• Determine power requirements of bogies on 1/12 and ¼ scale
• Determine safe limits for working with electric circuits around children
• Find a way to power bogie and charge battery from wayside
• Discuss several design solutions for wayside power and create a plan for narrowing down to a final design choice
• Work closely with the solar team and the track design team.

Sketches

Figure 1. Different collector shoe designs commonly used on electric trains

Figure 2. Collector rail preliminary sketch

Figure 3. Preliminary design for collector rail and shoe

Critical Path Schedule

Things to buy:

• Raw Aluminum for creating parts
• A 12” by 12” piece of stock Aluminum is $187.00, available here.
• Wiring
• Can be bought at HomeDepot.
• A battery for testing (need to decide 5 Volts or 12 Volts)
• 12 V, 5Ah battery for $15.00, available here .
• 6 V, 12Ah battery for $13.11, available here.
• Chose the 6 V instead of the 5 V because it was more readily available, the voltage can adjusted accordingly.
• Motor for testing
• Mini 5V-15V 12V DC Motor 360 Motor 6000RPM with Speed Encoder for $4.00 available here.
• Need to match the motors that the 1/12 model actually uses.

Preliminary Design Sketch

My idea for the wayside rail on the 1/12 scale model is to use the switch rail as the third rail (or current rail). The switch rail is the rail that is currently in place on the 1/12 scale track. The switch rail is used by the boogie to switch the cart from track to track. To make the switch rail a current rail too it would need to be insulated in some way. This could be done by using a conductive strip that is insulated from the switch rail. An Aluminum roller could then be used as the collector shoe and roll along this conductive strip. In the figure 1 below, the roller would roll underneath the switch rail, but the design could be revised for the collector shoe to be on the side of the switch rail or even on the top of it. The roller would then be connected to the DC motor and power the bogie. This idea is very simple, it will need revision in order for it to function properly. The scale model track sub team mentioned that they might completely change the track so the switch rail and support rail are vertically aligned. In this case, the model could be redesigned for proper function. Our team must work very closely with the track team in order to create a working 1/12 scale model.

Figure 1. Preliminary sketch of a collector shoe design, Google's SketchUp software was used

Wayside Rail and Solar Research

Wayside Rail

I am very interested in the wayside rail and the solar projects on the 1/12 scale model fro the Spartan Superway Project. The wayside rail will give the cars motors power as they move along the tracks of the Superway network. This rail on the full scale model will be high off the ground, out of the reach of any bystanders. But on the 1/12 scale model (which we will be showing at events), the rail will be just in reach for a small child to touch and an easy grab away for an adult. In the 2014-2015 Spartan Superway report they calculated that each car needs about 2 Amps of current (seen in figure 1).

Figure 1. Spartan Superway 2014-2015 current requirement calculations

This is a problem because we want to power multiple cars with the wayside rail, which will take more much more current. I have thought of a few different ways that we can avoid any accidents. First, we can insulate the outside of the wayside rail and the collector arm that will be protruding off of the bogey. This can be done with a liquid electrical tape, heat shrink wraps, or other means of insulation that will look professional. Once the rail and arm are insulated we could configure the collector shoe in such a way that it would be untouchable, much like these rails in figure 2.

Figure 2. Possible design for the wayside rail

The collector shoe could have a roller or a brush on it and roll or slide on the inside of these rails. It would have to be insulated up until the contact.

Solar

The solar project is also an interest of mine. I have worked with solar panels before when I was working for ESCO Electric. We did a few residential houses which is very different from the Spartan Superway solar system because a house requires alternating current (AC). This requires an inverter that changes the direct current (DC) from the solar panels to AC. Luckily, we do not need an inverter because everything we are running is DC. In the past, Spartan Superway teams have made solar systems that move with the sun. This is a very interesting idea, but it is not very practical for miles of track to have automated solar panels. Instead, a curved, aesthetically pleasing design should be implemented. Much like the design in figure 3.

Figure 3. Curved canopy solar design

This can be achieved with flexible thin film solar panels. Thin film panels are less efficient than a crystalline panel, which may be required due to the amount of amperage that is needed. I think it would be wise to get the wayside rail running with a battery first, then implement a solar system. 

First Subgroup meet (9/2/2015)

Our first subgroup meeting for the 1/12 scale model on the Spartan Superway Project consisted of a lot of organizing. Not everyone knew what they wanted to work on specifically. So, we made a list of projects that needed to be done and had people sign up for tasks that they would be interested in. This list included the wayside rail (gives power to the cars), the track rebuild (smooths out and increases the size of the track that the cars will be riding along), new cars and proximity sensors (adds more cars and gives them sensors so they do not run into one another), raw programing team (a lot of programming will be needed for multiple projects), solar (one of the main objectives of the Spartan Superway is to be self sustaining), and a birds eye view camera (this camera will watch the cars and track them from a birds eye view). This list is subject to change, we may add new projects along the way. I would have liked to work on everything because it all sounds very interesting, but I wrote myself down for the wayside rail and the the solar projects. Once we had made groups the session was over so that was all we did when we were in the Spartan Superway Workshop. At home I started looking up ways that we could implement the wayside rail. There are are many different ways to set up a wayside rail. The third rail system uses the support track as ground and has a third rail that the car would slide along with a collector shoe. This shoe collects current as it slides along the third rail. The only problem I can think of with this design is when we implement this on the 1/12 scale model it maybe a hazard to touch. This can be fixed though by insulating the outside of it to reduce the risk of shock.

About me

My name is Garrett Gemmel, I am a Mechanical Engineering Senior with a focus in Mechatronics. I am currently enrolled at San Jose State University. I have always loved building things and taking them apart. When I was young I started taking toys apart to see how they worked. If they were broken I would try to fix them. To this day I am doing the same thing, but now if something is broken and I cannot fix it I will get my soldering gun and start taking parts out that I need for other projects. This is where my passion for engineering came from. I have always been interested in mechanics and electronics, that is why I am focusing in Mechatronics, and that is why I wanted to go with the small (1/12) scale model on the Spartan Superway Project.