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Open-Source Personal Electric Vehicle

An electric vehicle, capable of carrying one adult, for less than US$2000 in material costs.

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A personal electric vehicle for (hopefully) under US$2000. Features will hopefully include: dual motors, upright seating position, energy harvesting (solar, human and regenerative breaking) in addition to mains charging, chain-less drive, pneumatic suspension with tilting mechanism. Wish me luck! (because I'm definitely going to need it!)

A major issue we face today is the issue of climate change due to the excessive burning of fossil fuels. While no project exists that can instantly reverse the effects of climate change, we do need to make progress towards reducing the amount of carbon released into our atmosphere. Electric vehicles and renewable energy sources can go a long ways towards reducing carbon emissions, and are technologies that the "everyday person" can access and use to accomplish this goal. I say "everyday person" with a grain of salt because, honestly, electric cars are expensive, and purchasing solar panels or a wind turbine for your backyard isn't exactly cheap or easy for the average consumer either. I personally like to do what I can to avoid excessive use of automobiles, not just because gas is expensive and I'm cheap, but also because I like to think that by reducing my usage of gas I am contributing less to the global issue of climate change.

I am a student at my local university, and since I live about 3 miles (5 kilometers) from campus I prefer to bike, weather permitting. When it's raining, or cold, or even snowing, I take the bus instead because nothing is worse than biking in poor conditions. I have long been interested in converting my bike into an electric bike, but since the majority of the school year in Michigan qualifies for the aforementioned poor weather conditions for biking it just doesn't make sense for me. That is, until I came across the velomobile.

Essentially a recumbent tricycle with a carbon-fiber shell, velomobiles are personal vehicles that are capable of high speeds for their size. Many come with electric motors to assist the occupant in propelling the vehicle. This seemed like the perfect solution to my personal problem problem of nasty weather, and also a solution for many others seeking a more affordable option to go green than heading down to the dealership to purchase an electric vehicle.


What makes this project unique will be the electrical and power systems on the vehicle. I hope to make a modular system that will allow a designer to pick which energy sources he/she would like to include in the system and to easily integrate them into the vehicle. These sources could include a human-pedaled generator, solar panels, regenerative braking, or any other energy source. This energy will be used to charge a battery bank and power the vehicle. A diagram of the power system this project will use is shown below

This project hopes to incorporate at least two strings of solar panels, if not more. Instead of wiring them simply in parallel, I hope to get more power out of them by giving each string it own module to maximize power output. Since the solar cells will be on the surface of the vehicle, the cells cannot all be facing the optimum angle towards the sun. With some cells shaded and while others are illuminated, typical arrangements would cause the power generated by the illuminated cells to be lost. By separating the cells into smaller areas and attaching each to its own tracking controller, output from illuminated cells should be maximized.

A highly underutilized alternative energy is human-power. Humans are moderately efficient energy conversion devices. Also, our fuel source (food) is highly sustainable and is not a significant contributor to greenhouse gas emissions. Also, the use of human power will make it so that a smaller battery can be used while still achieving long distances.

The charge controller will receive energy from the available sources and maintain a healthy battery charge state. It will also make energy available to the other systems in the vehicle. This charge controller will need to be able to monitor multiple power input sources, as well as maintain power to all necessary systems in the vehicle. Although they must exist in commercial vehicle systems, I have yet to see such a charge controller as an open-source design.

While it is not a primary goal, an auxiliary feature...

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  • Pneumatic Linear Actuator (part 1)

    Brian G.05/02/2018 at 13:45 0 comments

    While thinking about how my project could fit into the robotics module competition, there weren't a whole lot of options available besides the auto-leveling and tilting mechanism. This also has the benefit of being one of the lower-cost portions of the build and potentially requiring fewer tools as long as I can find a way to use off-the-shelf parts.

    First, I had to figure out what to use. I considered PVC, but I already knew going in that even schedule 40 pipes are not the best idea to use with compressed air. Since this system is going to be relatively exposed to the elements, the PVC will degrade with time, and I don't really feel like pulling shrapnel out of my butt when it explodes. After a little research I decided to give black pipe a go. I know it may rust with time, but it is readily available at hardware stores and, being made of steel, will be strong enough for the application at hand. Maybe someday when funds are better I will upgrade to an aluminum pipe solution.

    A trip to Menards gave me a wide playground of pipes and fittings to play with. Turns out that black pipe is schedule 40. Happy day! This meant that I could use a few PVC fittings. This would decrease the overall cost, and provide potential bearing surfaces for the actuator to slide on, provided the parts aren't going to explode in a way that will kill me if they break. The plastic-on-metal is going to slide so much better than metal-on-metal.

    After an hour of trying different pipes and fittings to get parts that closely mate, I settled on 1-1/2" pipe for the outer portion, and 3/4" pipe for the piston rod, with pvc fittings to create the head of the piston.

    Parts for the actuator.
    At this point, I had put down about US$25 on the build. In the end, I plan on having three linear actuators like this on the vehicle. Also, there will be a few other components needed in the end, but these parts comprise the main body of the actuator. I have to make sure this will even work before I start worrying about the rest of the details.

    I started by dry-fitting everything together. At this point, I'm not concerned about minor leaks between the fittings. I need to make sure the piston doesn't leak too much between the PVC cap and the walls of the cylinder.

    The top assembly is the piston, and the lower assembly is the body of the actuator.

    A perfect fit!

    The cap needed a small modification so that I can connect my air compressor, so I drilled and then tapped a 1/4"NPT hole to attach a quick-connect fitting for now. I was pleasantly surprised by how easy it was to drill through the black pipe!

    1/4" NPT hole was needed in the pipe cap so I could attach my air compressor.

    It's complete!

    With the actuator completed, it was time for testing. It didn't take long to find out there was an issue. Too much air was leaking around the piston, and my wimpy compressor couldn't keep up. Despite that, I was able to get about 40 PSI in the cylinder, and it provided a good pushing action. I think this design will work well for the vehicle suspension system, but I need a better seal between the piston and the inner wall of the main cylinder. Stay tuned for part 2 where I'm going to try some options for making that all-important seal!

  • A Journey Begins

    Brian G.04/21/2018 at 20:11 0 comments

    A few months ago, while combing the depth of the internet for information on electric bikes, I stumbled across a peculiar vehicle called the velomobile.

    I instantly fell in love with the idea of a small, enclosed vehicle that I could use to commute daily to university or to work, even in the harsh Michigan winters. (It's not very fun on my regular bicycle in all that snow and cold...) I began doing research on these vehicles, and realized that buying one was well over my price range, especially one with all of the features that I wanted. I figured I could probably build one (Eventually... You know what they say: "Give a thousand monkeys a thousand typewriters...") so I started looking into what features I would want my velomobile to have.

    After some more digging, I came across another interesting vehicle, the Toyota i-Road.

    I thought it was fantastic. If you haven't come across this vehicle before, you really need to see it drive! Once again, I poked around for where I could get this, and once again was disappointed to find out that it is only a concept car, test-driven only by a lucky few members of the media.

    At this point, I knew that I definitely wanted my vehicle to lean into turns the same way as the i-Road, and that the basic frame would be similar to a bog-standard velomobile. I was able to track down a few leaning designs for three-wheeled motorcycles and ATVs, and even for a trike, but none of them had any real information of how to make such a mechanism. Apparently, there used to be some plans for a vehicle similar to what I wanted, but they seem to be lost to history. Time to design my own!

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