Making a light weight electric car

arkmundi

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This is part of the ebike@technocopia.org endeavour to spark a local transportation paradigm shift (see below). One of the participants would like an enclosed, car-like experience. Understandable, we live in wet & often cold New England. Primary transportation for many will mean some protection from the elements.

My own approach was to simply adapt, meaning riding in the worst of elements. Most of my travel needs are for short-distance local errand hoping trips, for groceries and what-not. I merely layer up in trip appropriate clothing. And don't mind getting drenched if it happens. And though not ideal, riding on iced-up roads. I noticed that in the worst of it when the snow plows were unable to keep up, and in hilly Worcester, that I was managing better than most other people. Go figure!

So looking into the question came across Building an Ultra Light-Weight Car Part 1 and Part 2, where the University of South Australia has built the monocoque tub of an ultra lightweight and innovative, three-wheel electric car. Rather than using a steel or aluminium tubular space-frame structure, the strength of the vehicle lies in a monocoque constructed from foldable, aluminium honeycomb/fibreglass sandwich panels... and Adfoam ‘M’ grade modelling type expanded polystyrene blocks cut and then epoxy’d to the fibreglass/aluminium sandwich panels.

The approach, all using simple hand-tools, lends itself to a makerspace and folks doing as much of the work as they can making a light electric vehicle suited to their needs.
SouthAustralia.jpg

At first consideration, I'd be inclined to use Carbon Fiber-Large Parts 3D Printer posted in another thread. In part because Technocopia is in the business of 3D printers. But if there is a way to go from opensource CAD design software to STL file to carbon fiber impregnable mesh to finshed car, that would be really cool and part of the necessary paradigm shift to a new economy.
 
Another approach under consideration is take a very popular relatively light weight car like the People's Car, aka Volkswagen Beetle that lot's of folks have already successfully converted to electric {search]
Volkswagen.png
.. and one of the many fledgling electric car conversion companies like http://www.electriccarpartscompany.com/ for the various motors, controllers and whatnot needed to successfully convert.

eBay has lots of listings of Beetles from every year of manufacture and in various stages of dilapidation.
 
One alternative to paying over $500 each for those panels by the time you receive them is to make your own. I'm guessing they have 25mm aluminum with 4 ply 9.6 ounce bidirectional cloth on each side. A single skid of 40 honeycomb paperboard would run maybe $18 per 4'x8' for inch thick, less if you went half inch. Don't have strength specs compared to aluminum, but your shower might be fiberglas with cardboard underneath, as well as your hottub.

http://www.uline.com/BL_1856/Honeycomb-Pads

Shaping the EPS foam is a big job. You can start with a wire cut, but there's a lot of shaving with "Fred" then sanding, it's gong to have to be sealed perfectly before you put polyester resin on or it'll melt.

timthumb.php


A great start on all this would be to make surfboards/paddleboards/windsurfers, etc. A great undertaking for these workshops to add.

http://www.foamez.com/surfboard-diy-building-kits-c-23.html

There's a web community for it. http://www.swaylocks.com/forum
 
Dauntless said:
One alternative to paying over....
Many, many thanks. As soon as the Ross Mt Whitney class build is done, I'll be turning my attention to something along this line. I'm thinking something that is fundamentally a recumbent tricycle with a torquey powerful hub motor and an enclosure that is as much protective shell as it is weather protection. :mrgreen:
 
My Father had an Elcar dealership in the middle 70's. The lead acid batteries were a significant part of the weight. The model 1000 & 2000 corresponded to their wattages. The 1000 went 25 MPH, the 2000 went 35 (I think). Was a great car for our city of less than 20 sq. mi., and even though it would pay for itself in fuel savings its cost was similar to a base Vega, Pinto, or Gremlin and people had difficulty thinking 'outside the box'.
zele.jpg
zagato.jpg
 
arkmundi said:
Dauntless said:
One alternative to paying over....
Many, many thanks. As soon as the Ross Mt Whitney class build is done, I'll be turning my attention to something along this line. I'm thinking something that is fundamentally a recumbent tricycle with a torquey powerful hub motor and an enclosure that is as much protective shell as it is weather protection. :mrgreen:

why not repair your hybrid car and convert it to plug in hybrid?
 
arkmundi said:
This is part of the ebike@technocopia.org endeavour to spark a local transportation paradigm shift (see below). One of the participants would like an enclosed, car-like experience. Understandable, we live in wet & often cold New England. Primary transportation for many will mean some protection from the elements.

My own approach was to simply adapt, meaning riding in the worst of elements. Most of my travel needs are for short-distance local errand hoping trips, for groceries and what-not. I merely layer up in trip appropriate clothing. And don't mind getting drenched if it happens. And though not ideal, riding on iced-up roads. I noticed that in the worst of it when the snow plows were unable to keep up, and in hilly Worcester, that I was managing better than most other people. Go figure!

So looking into the question came across Building an Ultra Light-Weight Car Part 1 and Part 2, where the University of South Australia has built the monocoque tub of an ultra lightweight and innovative, three-wheel electric car. Rather than using a steel or aluminium tubular space-frame structure, the strength of the vehicle lies in a monocoque constructed from foldable, aluminium honeycomb/fibreglass sandwich panels... and Adfoam ‘M’ grade modelling type expanded polystyrene blocks cut and then epoxy’d to the fibreglass/aluminium sandwich panels.

The approach, all using simple hand-tools, lends itself to a makerspace and folks doing as much of the work as they can making a light electric vehicle suited to their needs.


At first consideration, I'd be inclined to use Carbon Fiber-Large Parts 3D Printer posted in another thread. In part because Technocopia is in the business of 3D printers. But if there is a way to go from opensource CAD design software to STL file to carbon fiber impregnable mesh to finshed car, that would be really cool and part of the necessary paradigm shift to a new economy.

I like it and it should be encouraged, but, what about the waste stream from this process and the use of toxic materials?
 
Just a basic golf cart seems to perform the same or better than many peoples light weight electric car builds that use lead acid (NEVs I believe they call them). Lithium is another story but super expensive. People are getting good numbers out of their light truck builds, small trucks with a big load of lead acid in the back. These seem to work nicely because they can actually hold all the extra weight of the battery required to get the thing up to fast speeds and long distances.
 
Hillhater said:
I fear my understanding of "large parts" may be on a different scale to these guys.. :roll:
... I'd be inclined to use Carbon Fiber-Large Parts 3D Printer

Hey, come one, it's gonna be a small car. Light, fits in your pocket. Remember the pictures of just how small CrazyJerry's Centurion is?

Anything like the variants of the Lotus 7, the LoCost, etc., are small.

Here is just another do it yourself car, claiming 650 pounds. Do you see anything large about it?

I've been thinking about this cardboard honeycomb with fiberglas to make my own version the Hanebrink Box. Now THAT is small.

ucar-comp-600.jpg
 
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