Greetings,

I've been designing an electric car that is aerodynamic, so that it should have a range of 300-400 miles on a single charge. I am going to build a prototype. Here are a couple of images of the latest SketchUp Model of CarBEN EV:


Here's my blog entry which discusses some of the design considerations:

http://neilblanchard.blogspot.com/2011/03/carben-ev-open-source-project-part-4.html

Here's a video animation of the SketchUp model:

http://www.youtube.com/watch?v=SXrqznFQ85c


If you would like a copy of the SketchUp file, I'd be happy to email it to you.

 

I've mailed in my order for a Phlatprinter 3, and after I receive it, I'll start building the CarBEN EV. Which will make me very happy!

 

Real ambitious project Neil, I wish you every success.

Tweakie.

 

Thanks for your interest! I am quite eager to get started building CarBEN EV. I know that this sort of thing can be done; as I know of two quite amazing electric cars; one built by Dave Cloud called Dolphin:

http://ecomodder.com/blog/dave-clouds-super-aerodynamic-electric-car-dolphin/

It uses lead acid batteries to achieve a 200 mile range, and the aerodynamics are amazingly good. I have made a SketchUp model of the Dolphin, as well. I'll try to find out from Dave Cloud if it is okay to release it.

The other electric car was built from scratch, and it was the runner up in the $5 Million Progressive X-Prize. They had a clutch failure, and they have since fixed that and 7 now can accelerate 0-60 in ~6.2 seconds. It is registered and insured and driven on US roads and highways -- the Illuminati Motor Works '7':

http://illuminatimotorworks.org/blog/
http://ecomodder.com/blog/illuminati-motor-works-shows-healthy-2075-mpge/

It also has a range of over 200 miles, on a ~33kWh lithium pack.

CarBEN EV is planned to have ~56kWh pack, and it should weigh less than both the Dolphin (~3,200 pounds) and '7' (~2,900 pounds). It should be similar in Cd to the Dolphin, or it could be even a bit better. Also, the Dolphin seats 2 and the '7' seats 4 people. CarBEN EV seats 5 people -- the driver and first 2 passengers can be ~6'-4" (my height), and the 3rd passenger can be ~5'-9", and the 5th passenger can be ~5'-0" or so.

I am looking forward to receiving the Phlatprinter 3, for sure! (The check has not been charged to my account, yet.) What serial number will mine be?

 

It will be #667 since mine is #666 :twisted:

Just kidding, of course!!!

 

My unit will be #80 -- in the meantime I have a few questions:

I need to make the 2" thick sections in pieces that are relatively straight and lay them out so they fit onto the 2' x 8' x 2" pieces of Dow EPS I am getting at Lowes. My question is how to best make the joints, so the pieces can be glued together -- I'm thinking about 90 degree "V' male and female surfaces?

How does the Phaltprinter 3 handle "undercut" edges? If I "print" a literal slice of the CarBEN EV model, some of the surfaces will be tapered outward from the top surface and the Z motion on the cutter will handle it, but on the other edges where the taper is under the top surface -- will the cutter just make a straight cut at the maximum; leaving the excess material in place so it can be manually removed later?

Will the edges that can be tapered be done "automatically"? Does the motion/feed rate have to be constant on all parts of the cutting, or does the software allow it to be changed, depending on the kind of cutting that is needed?

 

It may well be that the time needed to generate the 3D carving info will take longer than it is worth? Carving the steps off by hand is pretty quick really, so I may well stick to straight cuts.

Getting all the 85 sections split down into pieces and laying them all out on 2'x8' sheets, cutting them, numbering them, then gluing them up -- will be plenty to take on! I have to make the main chassis, and the hatch and rear entry doors, and the hood, and the front hinged wheel skirts, and the rear fixed wheel skirts, figuring out the battery bay (below the floor), buying a Smart ForTwo windshield and fitting that -- and then fiberglassing all of these inside and out...

 

UPS is going to deliver #80 sometime today!

I'm going to be busy building the CarBEN EV very soon.

 

I started assembling the gantry last evening! I think I have a lot to learn on the software front -- and I will have to be "juggling" 3 programs. I need to lay out the pieces of the sections onto 2'x8' sheets in DataCAD because I did not model ALL of the inside surfaces in SketchUp. I'll re-import the layouts into SU, and generate the g-code there.

And for some reason, in USBCNC I was not seeing what Mark was demonstrating on the DVD. I'll be asking a fair number of questions after I get into the process...

 

Very intriguing. I will be staying current with this

 

I've phinished assembling my PhlatPrinter III and it seems to work very well. I'll post a picture in that thread soon. Here's a video of a test run:



Some questions:

Is there a 2"+ cutting bit (with sharpening on all of it) available? If it is larger diameter, then can I compensate for this in the settings file?

It looks like the Z motion is greater than 2" -- is this correct?

I will be delving into setting up part layouts to fit on 2'x8' sheets and then making the g-code in SketchUp -- how and where does the tool path get determined? Is that done manually in USBCNC?

Where's the best FAQ on calibrating, and laying out sheets, etc.?

 

Do the g-code and slicing SU plugins work in SketchUp v8?

 

Yes

 

Great! I'm watching the Phlat Tools SU Basics, and I'm seeing that you do *not* want the sections to be 3D. Though the sides are always going to be straight cuts, and not have any 3D carving on them.

On a 2" thick by 2' by 8' piece of foam, how close can I cut to the front edge and to the rear edge? Is it 1" or is it more or less?

Are there 1/8" bits available that are longer and have longer sharpened sections?

 

Neil, I have a 1/8" bit that has a cutting length of 1.3". You can get them at Home Depot. I also have a 4mm bit that has a cutting length of 1.5". Look up Lowes or Home Depot.

I think you have to stay away form the edge at least 1.25" more or less. You'll see it once you'll put the foam in the PP and jog back until the front pressure roller is barely on the foam. That's the minimum that you can use. Same goes for the back.

 

Thanks, folks!

Is there a tutorial on setting up the USBCNC program with the full setting limits, and calibrating the zero position, based on the very tip of the cutting bit? Can I set up 2-pass cuts, so I can cut most of the way through the 2" foam? (Actually, it is 1 15/16" thick, and I have sliced the SketchUp model of CarBEN EV accordingly.)

Here's a screen capture of my initial try at laying out the 2'x8' sheets of foam in DataCAD:



In the upper right is an approximate layout of the first 2" thick foam sheet, to be cut on on my PhlatPrinter III. I need to redo it with an alignment "rod" in the SketchUp model, that will appear as 1/2" circles, like those shown on the red F2 section. I'll use dowels to align the sections as I glue them together.

I need to confirm the limits of the cutting area -- I think the righthand edge needs a ~4" band (on the 2' side) so that the X-axis friction rollers can keep hold of the sheet? And that means the F2-5 red piece will need to be moved up to the second 2'x8' foam sheet.

I also need to separate the doors, hood, wheel skirts, etc. so they can be made as pieces, and I'll have to design hinges for all of them.

 

Neil, is this like a full time job or do you do it as a 'side show' to your real job? There is a lot of work and time to be invested in this project and inquiring minds want to know.

 

Hi Yoram,

I work part time as a architectural CAD drafter, and it is almost ideal because I still have time to devote to building the CarBEN EV. I've been designing it for almost 2 years, and I am impatient to get going on the first full size prototype. I got to go to the X-Prize semifinals, a year ago in June at the Michigan Speedway. I was invited to be a guest member of the Edison2 team from Virginia by the owner, Oliver Kuttner and I was thrilled to be able to be there! Edison2 were the eventual winners of the $5 Million prize for the mainstream 4-seat category. They had four cars entered, and they are continuing to develop their Very Light Car:

http://www.edison2.com/blog/
http://www.edison2.com/photos/

I'm on the far left:


I learned a lot being there -- the Illuminati Motor Works team are driving their EV on the roads and highways, and I am hopefully going to join them!

 

Hi Neil,

First, I know you from the Datacad forum, love Datacad. Glad to find you've ordered a Phlatprinter, and built it. I've also placed an order for one, which should be coming soon.

Great EV car idea. Early days, but if I can put an idea in your head. Your design could allow for some sort of direct connection to solar panels. Also, there are now form fitting solar panels, about 50% as efficient as the standard design, but maybe they could be integrated into the vehicles body.

I have been following a car design from France. ( http://www.mdi.lu/english/produits.php ) They have been working on vehicle designs that run on compressed air. It has taken them a long time, but they are getting there. Anyway..great minds think alike I guess. Your design reminds me of their van type design...but it is designed much better I think. I really like the idea of a roof hatch that lifts for extra head room when needed.

So keep up the good work.


Good luck

 

I've been following your thread and have taken a look at your blog, curious question for you. You mentioned constructing the chassis yourself, I was hoping you might give us a run down on the proposed chassis configuration and associated components.