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CarBEN EV5: @NeilBlanchard 's Open Source Electric Car

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  • He was trying to post on the new Open Source Car category:

  • Greetings,

    I am new to this forum, and if this is not the right place for this, or if I should start a new thread, let me know.

    I have been working on a design for an electric car that I have named CarBEN EV5.  It is open source, and I am using Creative Commons on it.  It seats five people, and it should have a range of 300-400 miles.  It is meant to be very low aerodynamic drag, and be as efficient as possible.  I have just started building it, using a PhlatPrinter 3 which is a 3-axis CNC machine to cut EPS foam, straight from my SketchUp 3D model.

    Here's a link to my blog.

    I'll add more details soon when I get some more time.  I'd be happy to send you the SketchUp file(s) -- SketchUp is a free program from Google.  I have CAD drawings (though they are not quite up to date) and I have made the first couple of G-code files, which are used to drive the CNC machine.  I anticipate that building the chassis (moldless foam core composite sandwich) will cost me about $4K, including buying the PhlatPrinter 3.

  • Vote Up0Vote Down
    November 2011

  • Vote Up0Vote Down November 2011
    I think part of having doors on a car is also a safety issue. If you get into a car accident it's kind of nice to be able to get out by opening your personal door instead of waiting for the fire department to cut you out for even some minor fender bender that just happened to damage the rear and only latch into the car.

    And lets say you need to be collared and back boarded. In existing car configurations this is possible without having to do much if any cutting of the vehicle (as long as the doors open). In this single door arrangement the whole car would have to be dismantled to back board someone even if the rear door opens - at least that would be the case for the driver since even the opening roof doesn't extend all the way to the front.
  • I am completely serious, and I'm sorry if it came off as Spam.  I've been working on this design for a few years while I was not working -- but now that I am employed again (in architecture) I have much less time to build it.

    You may be right on the door -- I have to build the first prototype (which as I mentioned, I just begun to do) to see how it works.  I am concerned with weight and strength and I think this chassis would be safer in a crash than if it had side doors.  Or at least lighter and simpler to build.  I will be very happy to prove out the aerodynamics and range and all the myriad of critical things that it needs to have for maximizing efficiency; like the hinged wheel skirts, and how it works on the road in real conditions.  The electric drive train needs a lot of thought, and I'd like to work on using rigid wheels with super-low rolling resistance (like the Energy Return Wheel) and also to try out regenerative shock absorbers, like those from Levant Power.

    My goal is to get the energy consumption down to >100Wh/mile at 55MPH.

    As you may know, side doors can get jammed shut, so getting out of any car after an accident can be difficult sometimes.  Side windows can be broken out.  A roof escape hatch for the driver can be installed (like a sunroof or on a school bus).  The jaws of life can open any part of the chassis.  Or, I can add a side door -- it would have 2-3 latches in addition to the hinges, to greatly stiffen the structure and help the crash strength.

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    November 2011
    Neil: I'm quite sure Metz was referring to messages that were since deleted, not your post!
  • Okay -- I'm a little confused by this forum format; it is not what I am used too.
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    November 2011
    You would be very hard pressed to get any automobile to pass USA Department of Transportation standards with only one door, which would mean that any such vehicle as designed wouldn't be capable of being registered or street-legal in the US of A.

    I believe there was a tiny and ultra-cute French car that had only one door, back when I was living in EU, and I was warned that I shouldn't even consider getting one to take home, because US Customs would impound it until I could pay to have it modified to meet US DOT standards, which for a single-door car, would mean it would be impossible...

    Some of the other imports would only require minor changes, like putting tempered laminated glass in the front windshield, etc., but not that one.
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    November 2011
    How come we dont consider the m38 Jeep design?  It is out of any sort of patent and the design has already been replicated many times.

    The last three photos are of a M38 Jeep I built a couple years ago.

    jeep 3.jpg 39K
    jeep 2.jpg 30K
    jeep i.jpg 35K
    jeep.jpg 42K
    P1010754.jpg 200K
    pics2.jpg 132K
    P1010768.jpg 204K
  • Folks, another door could be added.  A roof hatch can be added, and widows can be broken out.  Most crashes are in the front and the sides and not having side doors
    makes it possibly significantly *better* for those crashes.  The driver sitting in the center makes it much better in head on crashes; because the entire front structure protects the driver.  (Look at offset front crash results versus full head on crashes.)

    The most important things about the design of the CarBEN EV5 is efficiency; and those need to be tested and improved.  This is a prototype, and it should be able to be driven on the roads and insured, etc.  A car is not a building, and even buildings with less than certain occupancy can have one means of egress.  In a home the second means of egress from a bedroom is most often a window.  CarBEN EV5 has windows.

    I cannot solve all the problems, and all designs are compromise.  I am trying not to compromise on efficiency, which is usually the last thing on the list.  So, less convenience if it allows for greater efficiency is a good thing.

    This car will get at least 200MPGe, and might even get 300-350MPGe.  It might be the most efficient car ever built, and certainly could be the most efficient 5 seat car ever.  It will travel 300-400 miles on a single charge, and has the potential with new batteries, like the DBM Energy Kolibri (Hummingbird) battery to go twice as far as that on a single charge.  Once I build it and test it and live with it for a while, and maybe build a few more generations of prototypes -- then I'll get to crash testing it.

  • Vote Up0Vote Down November 2011
    Neil, don't let our criticism deter you from your progress. You can always add doors later and redesign anything as necessary. I can't imagine that adding a door later would cut performance enough to have to start from scratch.

    What kind of drive train are you thinking for this vehicle?
  • Vote Up0Vote Down
    November 2011
    Something to keep in mind also, is that there may still be an "X-Prize" of sorts for accomplishing this.  I haven't recently checked, but there used to be an X-prize specifically for a high-efficiency automobile, although it only had a goal/requirement of 100 MPGe or better, it did have the requirement that it would have to be something that would be possible to go into production, meaning that it would meet current road safety standards, and still cost low enough to be a practical auto for a family car (not something in the Tesla/sports car range).

    I don't believe that anyone has ever won that one, so it may still be up for grabs, but OTOH, it may also mean that you have some other competition in that arena you aren't aware of, because it is not likely that any of the others would be open source...
  • I am going to use an all electric drivetrain, probably dual direct drive motors on the front wheels, and the battery pack in the floor.  I was planning on working with FVT who had their eVaro at the X-Prize.  The CarBEN EV5 drawings and SketchUp model show the EiG cells that FVT uses and their twin motor drivetrain.  It gets 100% of the braking power from regenerative braking, and is very quick 0-60mph (under 5s).

    I was able to go to the X-Prize Knockout Round in June 2010 as a guest member of the Edison2 team -- they were the eventual winners with their Very Light Car that got ~110MPGe.  They have since made an electric version that got ~245MPGe on the EPA Combined cycle. I was thrilled to be there and meet and talk to many people who have built their own cars.  The Illuminati Motor Works team is driving their '7' car on the road and they could have won the X-Prize if they had not put a clutch in '7'.  Electric motors are way too torquey with no lag, and they have lost several sets of gears in the transmission and the final drive.

    My PhlatPrinter 3 was not working properly today -- I tried to cut a foam sheet with the exact same settings as the previous time, when they worked fine.  The X-axis was skipping steps, and I thin the reason is the sheet was a bit wider and dragged a bit more on the roller side rails.  I will be swapping out the 2.5A per channel driver board with a 10A model and using a higher torque stepper motor on the X-axis.  Moving the whole 2" x 2' x 8' sheet of foam is hard for the 1A stepper, when it has any sort of snag.  I need a bit of "headroom" to avoid skipping steps and getting accurately cut pieces.

  • I will soon have more time to spend on getting my PhlatPrinter 3 working with a higher current driver board and a higher torque stepper motor on the X-axis.  The new board is poorly documented, so the settings will have to be trial and error.  I've ordered a Sharpie attachment so I can check the accuracy without cutting foam.

    So, hopefully I'll be able to report some progress very soon.

  • Vote Up0Vote Down
    January 2012
    HI Neil,
    You might want to look at the xr3 personal transit vehicle.  There are plans out there you can purchase.  125mpg on diesel alone with a top speed above 80mph.

    As others have said you can always add on doors and things later.  I'd be interested in helping.

    Good luck.
  • Vote Up0Vote Down
    January 2012
    I forgot to add.  I think trike is the way to go.  It's street legal because it will be registered as a motorcycle in most states. 
  • It has (obviously) been a while since I've visited this forum, and I've been building the first full size prototype of my CarBEN EV5 design!  Here's my photo album of the work process; that starts with the newest picture:

    CarBEN EV5 Build Photos

    I'm about halfway through the shaping and smoothing process, and I will try to start the fiberglass application as soon as the weather is warm enough.  If you want to start at the end of the design process and then browse forward through you can start here, and the browse using the left arrow.
  • Here's my blog post on the construction process of the first prototype of CarBEN EV5.

    The entire chassis is glued together and I am well into the smoothing process.  I will be starting to fiberglass in the next month.

  • I need to test some fiberglass samples for bending strength - does anyone have a jig that they have made to do this?  The samples are ~10.5" x 6" x 1" thick and I would like to at least get their relative strengths (6 different kinds of fiberglass fabrics and 2 surface treatments for a total of 12 samples).

    I'd like to test the bending strength either by a support on either end, and load it in the middle of the top of the piece, or in a cantilever mode.  If the strength can be quantified, that would be even better.

    Here are pictures of the samples.  I would like to use Titebond III glue (because it is no vapor, easy cleanup, and it has a chance at being biodegradable), and I think it is strong enough.  Testing the samples would help me at least get a feel for the strength, and if I can quantify it, that would be great.

    Thanks in advance for any ideas you may have.

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