Open Source Electric Car, CarBEN, Produces No Carbon

Raise your hand if you have designed and built a full size car…. Nobody? Doing so would be a huge task considering car manufactures have thousands of people involved with designing and building a car model. Eager beaver [Neil] has stepped up and taken on that challenge. He’s started an open source project he’s calling the CarBEN.

The plan is for the car to hold 5 people comfortably while being just a tad larger than a Scion xA. The body is made of foam and will be covered with fiberglass. The car is designed in a shape that tapers in towards the rear of the car and has features like a smooth underside and covered wheels to create a low coefficient of drag. The goal is for this beauty to get 300-400 miles per charge with an Miles Per Gallon Equivalent of over 224.

CarBEN Open Source Electric Car



So far, the body is the only portion complete but that is still a pretty significant accomplishment in itself. [Neil] designed the car body in Sketch Up and then divided the model into slices. He used a CNC Router to cut each individual slice out of sheets of foam. Then those slices were glued together and the exposed edges sanded to make a smooth shape. The process is documented extremely well on [Neil’s] site.

It appears the project has stalled a little or [Neil] just hasn’t updated the documentation of the project recently. Either way, we think this is a great project and look forward to seeing it progress.

74 thoughts on “Open Source Electric Car, CarBEN, Produces No Carbon

  1. I’m imagining a foam cooler attached to a frame, covered in a fiberglass shell.
    Now I’m imagining what would happen to it with the least little impact.
    Now I’m imagining the surviving members of the family adjusting to the loss of a loved one or…how many victims is that thing going to hold?
    No sir, I would not like to ride inside a bicycle helmet going at highway speeds.

    1. If you think the car will be a “bicycle helmet with wheels” then you are wrong. In order for a car to be street legal, it needs to pass a series of tests (including collision tests).

        1. Think of it this way: lots of performance and racing cars have fibreglass shells, they are safer than most cars due to a solid frame and a roll cage. I don’t know about this car, but I can say for sure that it won’t be a hollow fibreglass shell that tips over when someone sneezes next to it.

          1. Race cars have rollcages and bucket seats due to the fact that the outer body is no more than a thin layer of paint and fiberglass.
            And due to the rollcages being in close proximity of the head of the occupants of those vehicles, Helmets following safety requirements is a ALL TIME MUST.
            Same with a firesuit since even fire retardant fiberglass can’t resist much heat and flames.

            That ‘car’ can’t be designed with rollcages WITHOUT helmets being a must.

            There’s also a reason why pretty much all affordable cars have a steel body.
            Because it is cheap and easy to manufacture with compared to lighter materials.
            If this will ever be road-legal, then it’ll have to carry the pricetag of a asupercar in order to pay off the immense production costs.

          2. “Think of it this way: lots of performance and racing cars have fibreglass shells, they are safer than most cars due to a solid frame and a roll cage.”
            No, not really. They do not use fiberglass they use carbon fiber.
            “I don’t know about this car, but I can say for sure that it won’t be a hollow fibreglass shell that tips over when someone sneezes next to it.”

            How can you be sure of that?
            Composite construction is very strong when done right. So far from what I see I can not say that it will be done right. I did not see any molds and frankly moldless composites tend to be heavier and weaker than a good metal structure. I also can not say that it will be done wrong since it is not done at all.

          3. Composite construction is strong, but it has no rigidity past failure. Once it breaks, it crumbles like a cracker, unless you’re talking of more exotic carbon-fiber-on-sheet-aluminum etc. composites – which are also very expensive.

          4. This is true, but because of their solid frames and cages, they typically lack very much in terms of crumple zones and therefore require not only the drivers body to be firmly secured, but their heads as well. While some racing organizations have taken steps to design crash attenuators into the safety requirements of cars, the drivers still typically encounter massive forces an order of magnitude higher than you’d see in a street car.

            The trade off they encounter is very poor driver mobility as their torso is firmly secured into the seat with a harness that has a lap strap, two shoulder straps and an anti-submarine strap. Many professional series require drivers to wear a head restraint such as a Hans device to prevent the weight of their head+helmet yanking their neck in the event of a crash. All this boils down to a driver that can’t even turn around to see what’s behind them…. it doesn’t translate well to street cars.

          1. We don’t know for sure what he means by the word ‘foam.’ He might mean something that’s at least part like a viscoelastic, absorbing energy and turning it to heat in order to apply a decelerating force.

            Just wait for test results.

          2. Dan, I think what we can see what he means by the word ‘foam’. It’s the blue stuff in the picture that they say he used the CNC to cut layers of…

      1. Those tests, and the accompanying government certification, are massively expensive and, thus, will probably never happen if this is just a hobby project. That’s one of the main reasons why many of these small-time electric car projects that want to go commercial decide to go with three wheeled vehicles.

        In the US, a three wheeled vehicle still counts as a motorcycle instead of a car. Thus, it requires far less safety equipment and doesn’t require crash testing. The down-side of that (other than producing a much less safe vehicle) is that many states would still require the driver to have a special motorcycle driver’s license and/or require all riders to wear helmets.

          1. Actually you are half wrong. Right there on the page that YOU linked it says a motorcycle has no MORE than 3 wheels. 3 wheels is a motorcycle, 4 is not. I will grant you that it also says that a 3 wheel motorcycle requires only a class C licence, but it’s still a motorcycle, they just let you operate it with a C instead of an M1. That totally opens the question of how your insurance company will treat it, or how your rates will be since usually the first question with a motorcycle policy is ‘how long have you been riding?’.

      2. “In order for a car to be street legal, it needs to pass a series of tests (including collision tests).”

        In the US, this is only true for production cars. You can register your own home-built or conversion without a crash test, but you’ll still need to meet a laundry list of standard equipment requirements.

        1. All over the world that is true.

          they don’t take one of a kind hand built artisan vehicles and batter the crap out of them.

          the tests are destructive and thus only performed on large production run cars.

          In response to the post that started all this off…

          Having gone head first into a central barrier at highway speeds (from a motorbike) with my head protected by nothing more than “foam covered in plastic” I’d feel pretty confident about being safe whilst in that car.

          1. Having also crashed a motorbike and been thoroughly impressed by my (quite pricey) foam covered in plastic. I have to point out that a helmet saves you from impact because there is no room for you to move around in it. A loose fitting helmet will do you no good and to that, I make this point: Material does not necessarily determine safety factor.

      1. The difference is that Lamborghini has the money to pay an army of engineers and technicians to perform exhaustive Finite Element Analysis and crash testing to confirm their design as well as a team of QA experts to ensure that production actually matches the parameters called out by said design.

        1. No to mention the price of a Lamborghini.
          And that is when we factor out the exotic drivetrain components and interior materials, the profit margin and the salary of workers.
          In comparison to a all steel or aluminum construction that can easily be done with robots as a speed, efficiency and precision that keeps costs way down and quality way up (unless the design is deliberately gimped).

          Especially consider the design and material choices of existing high mileage hybrids and electric vehicles made på professional companies on a large scale while still having a affordable pricetag.

  2. Please, stop saying that electric car doesn’t produce carbon .

    Carbon is not directly produced by the car but is produced by the power plant that produces electricity and factory that builds parts of the car.


        1. Building a solar panel, dam, windmill, or a nuclear plant (all of which aren’t going to last forever) without producing any CO2 at all would be pretty impressive. Dams and nuclear plants use a lot of concrete which if I recall produces a lot of CO2.

          I guess even if you had one person build an electric car and a solar panel without producing any CO2, it would still technically not be totally carbon free because of all the time they had spent breathing while making it.

          1. @lim,

            You are technically wrong about the person building a solar panel not being carbon-free. Technically, everything that does not bring more carbon in the atmosphere is carbon-neutral.

            Burning a ton of wood is carbon neutral, burning a gram of gasoline is not. Why? It’s because the carbon on gasoline was not in the atmosphere, but the carbon on the wood was trapped by the tree before you burned it, so the equation will cancel itself.

          2. Call me when the industrial processes that produce solar panels run on anything other than fossil fuels. The dump truck that hauls the ore for the materials, and the ship that carries it across the world still runs on diesel, and the refinery and manufacturing plant run on almost anything but clean renewable energy because the renewable energies are intermittent and ill suited for industrial processes which require steady cheap energy.

            Hydroelectric dams and reservoirs also emit methane gas because of the fluctuating water levels which wash down plant matter from the river banks into the sediments where it rots, which is worse for the climate than CO2.

          3. @thoriumbr

            “Burning a ton of wood is carbon neutral, burning a gram of gasoline is not. Why? It’s because the carbon on gasoline was not in the atmosphere, but the carbon on the wood was trapped by the tree before you burned it, so the equation will cancel itself.”

            The carbon from the atmosphere was trapped by trees before they were buried and turned into oil by time.

            Burning wood DOES release carbon into the atmosphere, it’s just a shorter cycle.
            Basically, we can say that planting trees is likely carbon Neutral (even when taking into account heavy machinery used in large scale forestry management. but burning wood will always release trapped carbon, just like burning petrol releases trapped carbon.

    1. I would even push it further: this title is nonsense. How much would production of this car cost environment? Especially apart of co2 which is at least non toxic gass.
      And than, when it will finally be at use how much co2 (and other important gases which are so easily omitted) would be produced in normal use? If you are happy user of atom power plant, than instead co2 I would ask how much vapor will be produced. Why vapor? Because it’s main cause of greenhouse effect, and nobody bothers to count how much of it we actually produce.

      But I like the project – even if it won’t run more than 50mph, it would be great mean of locomotion for city. Generally EV would be efficient if used in smart grid, charged at night, as you can’t just turn off your average power plant for night. Hopefully future will bring us ultra light, super power batteries so that we could use efficiently what we actually produce ;]

      1. Let me draw a careful distinction between electric vehicles as a hackaday project and electric vehicles as a whole.

        I fully support, appreciate and respect anyone who attempts an undertaking of this kind. Please, by all means, tinker, experiment, and dream. There is no down side to this. The first Ford, by the way, was built in Henry’s shed.

        That said, I not only think the notion of rechargeable automobiles absurd, I might go so far as to say that I oppose them.

        The primary issue of building a practical car is one of energy density in the energy storage medium. In the case of gasoline, the energy density is high, so it takes comparatively little fuel to go long distances between fill-ups. Battery technology is not sufficiently advanced to compete in this arena, and we aren’t going to get there by simply shrinking the size/weight of the of car because other factors like safety and useable payload come into play.

        “Well,” you might argue, “battery technology is going to advance. Fine, let’s suppose that’s true and battery storage capacity doubles or triples in the next five years. You still have a problem. When you “recharge” a gas-powered car by filling the tank, what you are really doing is transferring large amounts of potential energy in a very short amount of time.

        In the case of the battery, you must also transfer large amounts of energy. The problem is that unless your vehicle is for fleet use (mail truck, for example) where overnight charging is acceptable, the KW transfer rate is necessarily huge. Here is where you run into inescapable laws of physics. Either your charging voltages have to be absurdly high (which creates user-safety problems) or the charging current has to be absurdly high (in which case efficiency suffers due to I2R losses. )

        Finally, the LAST thing I’d want to see happen is nation 250 million electric vehicles. The existing power grid is only marginally capable of producing what we need as it is. After 3-Mile Island, Chernobyl, and now Fukushima, reactor projects don’t have a snowball’s chance in hell of being approved. Within the last few of weeks, Obama has enacted EPA changes that will all but prevent another coal-fired plant from ever being built and he himself admitted that this is going to cost utility users big-time. And while wind and solar offer some potential, they will never produce more than a fraction of the power we need. All of this will invoke basic principles of supply-and-demand meaning that the price of residential electricty would double, triple, or more— and that’s if you don’t suffer rolling blackouts during peak-use seasons.

        As an engineer, I think that electric drive trains are fabulous. I have no doubt that they will eventually supplant internal combusion engines– but not in a rechargable electric vehicles. Electric fuel cells are the future. This keeps an electric car off the grid, yet allows us to use most of the existing fuel-delivery infrastructure.

        1. The price of electricity will go up. You are correct about this. However, out of desperation comes ingenuity. Life changing ideas slipstream into inventions, and thus change the world. If we are happy sucking down power that pollutes, why spend the money or brainpower. Why innovate? Because we as humans are lazy, and if what we have is working, we will beat it till it’s dead.

          Regarding your other statements about battery charging–yes there are limitations. If charging at high currents, new safety requirements will crop up. Just as there were scares of using cell phones while pumping gas, there will be similar wives’ tales of getting vaporized why charging up the Prius. Secondly, battery technology is infantile. We certainly have missed several combinations, which could lead to gasoline-like energy density. Graphene, although not a battery, has received enough attention that it warrants more research and development. It would overcome the internal resistance that batteries impose (thus heating issues you relayed) and the capacity is growing as new techniques in production are researched. Just give it time.

          As I said, we are powerful problem solvers as a species. This ability peaks when we are in a dire situations. When there is a desperate need for something, we find it.

          1. There is another issue with batteries. Gasoline is inert on its own, whereas batteries already include all components to release the contained energy.

            The higher the energy density of the battery, the more destructive it becomes when it breaks. At some point you’re literally driving on top of a landmine, and all you need is a piece of metal through the bottom like with the Tesla battery fires.

        2. “And while wind and solar offer some potential, they will never produce more than a fraction of the power we need. ”

          That’s not the real problem. Wind and solar power are very scalable and they can easily be used to provide for secondary loads such as heating or cooling where you can store energy in hot water and ice, which account for roughly 4/5th of the actual energy demand. They just have one fundamental problem: they will never produce more than a small fraction of the direct electricity demand WHEN we need it.

          The main issue with electric cars is the charging issue. An electric car is on par with a regular four person household in the US in terms of yearly electricity consumption, so when a significant number of homes have electric cars, they necessarily have to restrict either when you are allowed to recharge yours, or how fast you are allowed to recharge yours, and crucially: how much you are allowed to recharge yours to keep the demand for electricity from surging uncontrollably during certain times of day.

          If you set a limit to no more than doubling the peak electricity consumption per household over the baseline, you are effectively restricting your ability to charge the car to somewhere around 40-50 miles a day in the US and 20-30 miles in the UK and even less in many other European countries where the average household electricity consumption is less.

          1. Wind and solar electricity generator (turbines, panels, etc etc) takes DECADES before the pollution footprint that is unavoidable with constructing and setting them up is ‘neutralized’.

            Focus on improving reactor designs for future nuclear reactors, actually calming the overhyped public believing in bullshit and lies and constructing new reactors in areas where natural disasters are either rare or predictable (and thus possible for engineers to account for) is the only way to go.

            It isn’t a ‘feel good’ solution, but it is the only solution that’ll work without jacking electricity prices up so much that poor people suddenly can’t afford it anymore.

        3. I am in ave that I found such a well though and written reply.

          I’ve to agree what you said about power density, as it is a fact no one can deny, I can even add that even though lithium battery types have great power density there is too little lithium in the world to mass produce cars with it. Although future lies in fuel cells. What is arguable are lighter and smaller electrical vehicles which could be very efficient, especially in cities, when you do not need either speed, or much capacitance. I actually believe that in close future we will be seeing more and more “toys” like that. For me it too early even to think about trucks solely on electric engine, but you have buses in cities which are hybrid, which actually makes sense even now.

          As you probably know there was idea of “power stations”. Instead of charging points, why not to replace batteries. Reply shall be “but number of charging cycles is limited”, yes it is, however if you are not in posses of battery, but are using it in leasing it is a different story.

          Now I shall calculate how much % of cars would be needed to flatten daily power consumption curve, but it doesn’t matter, what matters is that if it could be flattened, huge amounts of energy could be spared, smaller spinning reserves would be needed and so on. As a fellow engineer I would love to see it, it is a kind of dream. (Just the beginning of it – further are huge power banks to store wind power… )

          But fuel cells are rechargeable, so this vehicles will be rechargeable :) I can’t wait for affordable, one person, car/motorcycle mix which I could ride daily!

        4. Your post reads like one of those paid FUD posts that pop up under every EV article on the net. You’re essentially wrong on every point you make. All of them have been debunked many many times before.

          Energy density: Yes it’s a fraction of gasoline but with electric propulsion being 5 times more efficient than ICEs that’s not as big of an issue as you make it out to be. The EV drive train is much smaller and does not require megawatts of cooling power, leaving much more room for batteries and passengers. To argue that usable payload is impacted when the Tesla model S has 200+ mile range, seats 5 adults and has more trunk space than equivalent ICEs, is absurd.

          To claim that overnight charging is not acceptable for anything but fleet use is even more absurd, the exact opposite is true. Imagine that you wake up every morning to fully fueled car, you drive to work where your car sits in a parking lot charging for 9 hours, you drive home. Absolutely no need for fast charging except when you go on long distance trips or drive around all day, like a delivery truck.

          Efficiency does not suffer much during fast charging. The conductors are larger to compensate.

          Your final point point managed to squeeze in everything from nuclear FUD, Obama FUD and coal power FUD. You, of course, forgot that extracting and refining fossil fuels uses a shitload of electricity. In 2014 refineries alone used 44,635 million kWh of electricity. That’s enough to drive 148,783,333,333 miles, yes 148 billion miles. That’s almost 500,000 miles for every person in the US.

          I’ll just leave some links regarding grid capacity and EVs:

          As an engineer, I doubt you’re an engineer.

        5. So what you do is simply swap out a battery pack when you need to recharge. The unit goes back on the shelf to recharge over the next day and we are all OK. Possibly in less time than it takes to fill a tank.

          However this will require the industry to standardize on a battery pack. (or even just a battery size and connection type).

          This is something that will happen quite quickly once it becomes cheaper and more convenient to run an electric car.

          At the moment electric bicycles are exceeding car sales, but car use is still much greater than bicycles.

          Just remember that ROVER once was a bicycle company, and that the future of electric vehicles will follow the same course. First bicycles, then scooters, then road vehicles, then trucks and busses.

        6. I drive an electric motorbike to work every day in Viet Nam. I charge it overnight, and it’s awesome. Electricity is mainly hydroelectric here and petrol is quite expensive. A middle class salary measured in petrol would be around 10 litres a day.

          Traffic is heavy (you’ll average 15km/hr), so the fact electric uses no fuel to idle is nice. It’s cheaper than an ordinary motorbike too, at VND 5.200.000 (around USD260).

          There are basically no vehicle safety laws here, so you can just drive any weird thing you welded yourself (this is a significant minority of vehicles, some pretty cool). I’ve seen electric golf carts on the highway.

          In other words, if you make an electric car that can hit 40km/hr, is a smaller than a full size car, and has a range of over 30km… that would be awesome here since ‘normal’ cars are ridiculously expensive, and families don’t really have a good way to transport young children here for short commutes (school, etc.).

          I think electric vehicles are immensely practical now, they don’t even have to be very good, just make them cheaply please! Foam is fine, it’s safer than what we have now.

      1. I dare you to dress up in a nice white shirt and pants and take a tour through one of those plants :P
        All that black smudge you’ll end up with on the clothes is not CO or CO2…

      2. Technically, if a car or power plant has inefficient burning and produces soot, it produces carbon (from hydrocarbons). Diesel engines are particularly bad here.

    2. A solar panel has a two year payback in terms of the energy input required to manufacture it. It then has about a 25 year lifespan before it degrades to the point at which it’s power output drops (it is an exponential function, dropping off rather rapidly). So there is no such thing as a “Zero Carbon” solar panel. In addition the energy storage system would most likely use lithium, which is mined from a giant pit in Bolivia, and it’s so large that it’s VISIBLE FROM OUTER SPACE.

      1. It won’t be long before some of the larger chinese solar players eat their own dog food. As tax & power incentives dwindle or they are outpaced by expansion (eg 2016), they will farm their own solar power. There is zero reason why the vertically integrated manufacturers can’t go from silicon to module on solar power alone. As far as storage, lithium chemistry is unnecessary and overpriced for stationary applications.

        These solar power vs. oil vs. thorium nerd discussions all culminate in hilarity as a bunch of myopic twits finally reveal their delusional binary reality where with solar everything or solar nothing. In this mythical wonderland they are utterly ‘unimpressed’ unless solar can completely displace all forms of energy conversion, a feat seldomly if ever expected from other sources. Solar @ 10% of global energy at 6 c/kwh (already available) would make it the 4th largest industry on earth. There are no barriers technical, economic, or political to this level of penetration. It is inevitable. Carry on.

    3. I answer to all who have react at my comment.

      What i want to say, that is dangerous to say”the electricity don’t produce carbon”
      We have to stay objective.
      I guess Electric Car will contribute to reduce or to control carbon rejects more efficiently.

  3. Not sure about the seating arrangement, Having 3 people on one side of the centre line and 1 on the other doesn’t sound great for handling.

    The project feels a bit “horse before the cart”. As far as I can gather, apart from a few ideas, the actual chassis, controls, drives, etc. haven’t been fleshed out with the body the only part with any detailed development.

  4. Covering foam with fiberglass has been used successfully for years in safe, street legal vehicles. It’s stronger than the fiberglass bodies used in most kit cars, which only use a single layer of ‘glass. The foam ‘sandwich’ creates a double wall body. (Look up the Tri-Magnum and other vehicles designed and built by Robert Q. Riley.)

    The CNC machine used to cut the foam slices is a Phlatprinter, seen recently on HAD.

    What will likely be an issue with CarBEN is Neil wants to use Titebond wood glue in place of epoxy resin. He can’t use polyester resin because the foam he used is a type that polyester resin will dissolve. On the ecomodder forum we attempted to convince Neil that using wood glue would be a Bad Idea. Dunno if he’s going to use epoxy or not. The glue is a cheap and quick method for concept models (even ones that might be driven just a bit, on closed tracks, not very fast) and things like set pieces and props for plays, movies etc. But no way would I trust it for a vehicle to use on public roads, not even keeping to 25 MHP or slower city streets.

    Why there’s been a lack of progress is because of the “structure” he was using as a construction area. His tiny one car (or more likely one buggy shed) garage was too small so he rigged up some wood and tarps in front of it and this past winter the snow caved it in and somewhat smashed the body.

    He’s been gluing the pieces back together while making plans for an “addition” to enlarge the shed by 4x or more so he can work inside and be warm and dry, without any more snow crushing delays.

        1. Really? If he did, in fact, add onto his garage using nothing but tarps and some bits of wood, it should come as no surprise that it did not withstand snow loads realistic for his region. There is a very good reason that building codes exist and that they be followed. I concede that I am not a contractor or professional builder or structural engineer, but every structure I have built has passed the necessary inspections the first time. He actually created a dangerous situation and it’s fortunate that the ONLY thing damaged was his car project. Again, hopefully he is a little more thorough with his car than he was his garage.

          1. I’d like to direct your attention towards the GPS Block-IIR satellite, which on 8 May 1999 got drenched with rainwater, after the plastic sheeting that covered the satellite (because the leak in the roof was known) pooled enough water to tear off the tape that hold it together, spilled onto the satellite and racked up $2.1e6 dollars of damage. That was the clean room atop Pad 17A at Canaveral.

            Such things happen in better families.

  5. Seems unnecessarily high… there is no reason to keep the passengers upright like that, tilting the seats backwards like in supercars will get you a lower profile, just like a…supercar…
    Also, starting with the body instead of the actually critical car parts will most likely result in a disappointment, if not straight disaster.
    A car has to first and foremost be able to start and stop moving, then anything else :D

  6. Having formerly worked in the auto industry for 8 years, I can positively say that no matter how fuel efficient a car is, how technically advanced or drag-free, if it looks like a dog its going to sell like one.

    The body design may be ultra drag efficient but you wont catch me setting foot in it. Get rid of the wheel covers, put some shape back in the rear end and restyle the front then maybe he has a shot.

  7. It’s worth noting that this thing only has one door and its in the back. Get rear ended and get trapped. It wouldn’t pass safety inspection where I live as a multi passenger car

  8. A lot of guys use this type of foam building technique to create fiberglass parts for motorcycles. Use duct tape or even wrap the thing in cling wrap to keep the epoxy from sticking or melting the foam.

    My problem with this is…start with the inside dude! Doing the easy visuals first is destine for project burnout.

    Is he planning on molding in sections or attempting to make one big car shape like a vacuum formed r/c car body?

    Why is the hood open?

    Imagine how much power he used to CNC all that foam? The toxic fumes and nasty dust?

  9. I would rather see the design of the drive train before I see what the car as a whole looks like since the former supersedes the latter as far a design considerations go.

  10. Having researched this many years ago, I can still not believe how expensive this foam is to buy! I had designed a car many years ago, and was going to build a mock-up body to create castings for molds, but the foam was so expensive that I couldn’t afford it after the costs of the glass and resin. It would seem to me that simple foam would be less expensive. I priced a piece of heavy load foam(that I found on the side of the road) at about $80US for one piece at 3’x10’x4″ size…

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