Believe it or not, the writers here at Hack a Day do their own projects too, we don’t just write about yours! I’ve just started a new project, and I want your advice! A few friends and I are converting a custom-made dune buggy — to electric.
The project will be chronicled over on Hackaday.io, with (hopefully) weekly updates on our progress. If you’ve been perusing Projects, you may have noticed my Electric Car conversion from a few years ago. First year of my engineering degree, my friend and I converted a 1993 Honda Del Sol to electric, using the guts of an electric forklift.
We got it going over 100km/h on used batteries our school donated to us. Unfortunately, there was a bit too much red tape and bureaucracy for us to get it on the road legally. That and we were poor university students who couldn’t afford new batteries, or the ridiculous amount insurance companies wanted to put it on the road. The project got scrapped after sitting in the backyard for a few years.
Fast forward to today, and we’ve both graduated and are working our “cushy” engineering jobs, and for the first time in our lives, we have some disposable income. We needed a new project to work on.
Introducing the Flux Buggy. We found this dune buggy / go kart on Kijiji for $1,500. It was actually custom made for the guy selling it, and we’re impressed at the build quality. The whole thing is made of 1-1/4″ steel tubing, all the bearings and pivot points have grease fittings, there’s aluminum tread plate siding, and some good quality brakes! We’d be hard pressed to even be able to buy the parts for that price!
It originally came with a 13HP Honda engine, which could get it going around 50km/h — slow acceleration though since it was direct drive — no transmission. We sold the engine for $300 and brought it home… on top of a truck!
This was about a month ago. Since then we’ve bought half a dozen marine grade 12V lead-acid batteries, started machining the gearbox, and fabricating battery mounts off the side of the buggy. I’ve been taking videos along the way and will try to release new ones on a weekly basis. Take a look and let me know what you think!
Now — this is where we need your help! Suggest things you want to see — we don’t care how crazy they are!
- The Name:
We need a better name for this. We thought about calling it something silly, like a person’s name –like Sven. But the only way I’m willing to do that is if SVEN is actually a clever acronym for the vehicle. - Upgrades:
We’re planning on having two sets of tires for this bad boy. 17″ knobby truck tires for off-roading (it will look like a giant RC car with those proportions), and slick regular tires for the track.It will have two gear ratios for now. High speed, and high torque. We’re expecting about 111km/h for the high speed version (we’ll need seat belts) and only about 60km/h for low-speed — but will it ever go! What do you want to see? Paintball gun turrets? LED flood lights? Sound system? Auto-pilot? Flight mode? A turbo button? Let us know! - The Videos:
Be honest — were they boring? I’m working on cutting things down as much as possible to keep it entertaining, and interesting. What do you want to see more of? What do you want to see less of?
I think that’s all for now. We hope you like it! Don’t forget to follow it on Hackaday Projects — the next time it hits the front page probably won’t be until we test drive it!
First things first; Scrap that lead-acid and go for li-ion.
Agreed. It’s very rare in the EV world to see people doing new conversions with lead acid these days. LFP costs twice as much, but you don’t have to replace them in 2 years like you will with lead.
“Some” disposable income.
We may actually upgrade to li-ion down the road, but for now lead acid will do just fine.
What is the capacity of the lead acids pack you will be running?
Disregard, I found it on your IO project page.
A replacement Lipo pack composed of high performance RC cells would run over $2600, and a pack comprised of 18650 LiIon cells over $2200…ouch :(
Yeah — the lead acids ran us just under a thousand. Not to mention we already have big battery chargers. You need fancy ones for the lipos as well, which will run even more sadly!
Actually, the LiPo idea intrigued me so I did some more digging. At wholesale you could build your own pack from 18650s for just over $1000 for the cells. Obviously, the wiring and pack structure would bring the total up a bit, but still, not bad.
Any time you build your own LiFePo4 battery pack, you also have to build a bmi to protect the cells. The components for a bmi alone would cost about $1000 not to mention the weeks of wiring.
Lead acid batteries are cheap, and easy. They don’t need special electronics and they don’t explode when you abuse them.
Where are you getting this $1000 price for lipo batteries? Any time I have looked for a 72V 200AH battery pack with at least a 5 coulomb output, it has been over $3000. 18650 batteries are generally around 1 coulomb meaning that they could never supply enough current for an EV.
BTW, I am the friend working on the buggy with Mr. Hobson
Hey Ian,
Great project you guys have here :) The numbers I presented are based on a couple assumptions:
1) A 20S (72v) 140Ah pack (same as your lead acid)
2) Using the same format and chemistry of cells as the Tesla S, ie 18650 Li-Ion not a LiFePo4 based cell. Tesla uses the Panasonic NCR18650A which will have better performance than the wholesale 18650s I was looking at however for a dunebuggy they will work.
3) Max pack current not to exceed 450A, the same rating as your Speed Control.
4) Running the 18650s at about a 3C discharge (peak), understanding that we will lose a little capacity in the process. If we take 450A/140Ah we get a 3.2C discharge rate which will not damage the cells assuming they have sufficient cooling and of course still thermally monitor for safety. In the RC world ( I have been flying electric RC airplanes for nearly 14 years) we would routinely run burst discharge rates of 5C with no adverse affects and constant discharge rates of 3C with hundreds of trouble free cycles. Granted, in aircraft you always have access to plenty of great cooling however with good modular pack design it is totally feasible.
A BMI is definitely a separate issue however rolling your own should not come anywhere near $1000 for this size of pack. Also, if you design your own you decide the resolution with which you monitor the pack. ie, monitoring every single 18650 cell is not necessary for reasonable pack performance or safety. You can create parallel modules of 25 cells than series 20 of those to create half the pack. Make a second one and parallel them and you have a full, 140Ah pack. Thermally monitor with high resolution since those are extremely simple/cheap to implement and tell you a lot about how your pack is performing and than charge/monitor your 1S/25P modules individually to make guarantee your 20S voltage balance doesn’t get thrown off.
Traction control? and a giant custom stepper motor drive, eliminating the gearbox. (ok, that’s a bit much… but I was serious about traction control.)
Kinda sad to know that I’m not the only one who had the same (terrible) experience with EVs and red tape. I worked on a project a several years back (almost 8 now?) to convert a 3/4 ton GM pickup to electric. We got it to run, and even got it street legal, but it was a massive kludge and was eventually scrapped after water got into the controller and it nearly caught fire. (this was a few years after when I was no longer on the project) ;)
What exactly were the legal issues? Getting it to pass inspection? Would things have been different if you had tags while running on gas before the conversion?
That’s what I was thinking, how would they know about the drive train changes?. Here in Kansas we don’t have vehicle inspections of any kind. I suppose if there are annual emission tests, they’d discover changes , and regulations aren’t set up to handle that.
Ah yes, I forgot to mention the ‘red tape’ part. The vehicles had been converted to run on propane as part of an experimental program prior to being donated by GM. As such, they were donated under a scrap title in order to prevent any future repercussions of liability issues related to that conversion. It didn’t seem to matter that we had stripped just about everything out, and the as-received vehicles had been converted back to gasoline anyways. Either way, it was a huge pain in the ass to get them titled, and in the end it was done through a loophole of some kind.
That doesn’t sound too bad. Here in Australia even if you changed the gearbox type or changed from 2wd to 4wd (or even an easy 4wd->2wd conversion) to anything that wasn’t a factory option you need to register the car like a home built kit car. That means chassis rigidity testing, complying to current emissions standards, having an engineer certify every aspect of the design etc.
I should also mention that this was in Pennsylvania. ;)
Sounds less like a loop hole and more like some supervisor just issued a title even though there were some invalid fields.
As for a name – how about “E-Go”?
SVEN – Sven’s Velocity Excites Naysayers
Aha!
Tank track version? or at least 4WD?
We actually have a few more forklift motors kicking around and I’m planning a mini tank after this…
First thing I’d complete the roll cage adding the missing pipes going to the front of the vehicle…
Yeah we were wondering why that was absent!
Because it’s a roll bar not a roll cage? As a roll bar it looks to be a substantial as those found on agricultural and industrial tractors. Although an X brace inside it’s perimeter couldn’t hurt.
D Bug
I love the idea of giant knobby R/C car looking tires. I don’t know how you are going to get any kind of good speed out of this thing with that much lead-acid deep cycle marine battery weight. I know LI-ION might be a more expensive option but they would be muchhh lighter and better discharge. Either way ~ this thing is going to be HEAVY!
Yeah, the batteries weigh 406lbs alone.
That being said — same setup got a 3000lb car going 100km/h. So… a 1200lb go kart will go plenty fast!
It’ll get excellent acceleration compared to a car, but you might not get as good top speed unfortunately. I’m a motorcyclist and can attest to the poor aerodynamics of bikes and other brick-like objects (aerodynamically speaking your buggy is too) causing an exponential drop-off in top speed vs horsepower, which starts kicking in far sooner (80-100kph) compared to a nicer car shape.
That Princess Auto place seems like a maker’s dream! Do places like this exist in the US? I’m only aware of Grainger and the like, and they’re mail-order only and a pain to deal with if you’re not an account holder.
Oh it’s a great store. It’s a Canadian chain, I’m really not too sure what the american equivalent would be…
They sell tools too but they usually aren’t the best quality. If I won the lottery I’d go to that store and make an Alien exoskeleton suit. They have everything you’d need.
Awesome. The closest comparison I can think of in the US would be Harbor Freight Tools. But they just do cheap tools. Never seen a place in the US where you can walk in and buy chain and sprockets. I’ve seen -some- chain ate Lowes before, but a very limited selection and crazy prices. Maybe I’ll have to look for a farming and agricultural equipment place.
are you kidding? You need to pick up the yellow pages for your nearest city.
Give me some names of places to look for! Mainly in the SF Bay area :-)
I live in Massachusetts, but Google yielded this place for you http://www.1sourcedist.com
Most coastal cities have industrial suppliers.
YP has all flavor of suppliers. http://www.yellowpages.com/walnut-creek-ca/bay-area-industrial-supply
http://www.northerntool.com/ I have been in the Wichita, KS store they do keep a lot there. However this is the oil patch, and I can get a lot of stuff at local supply stores without making a 6 round trip drive. Even though I don’t no longer spend a large amount of money doing the work of my former employer, an dependent oil producer, they still treat me right.
Mill’s Fleet Farm, L&M Supply, Northern Tool, Blain’s Farm & Fleet and Tractor Supply Company are all similar stores in the upper Midwest (USA). Mill’s Fleet Farm are WalMart sized stores that are a hackers wet dream. When I’m working outside the area I find myself wishing for such a store.
Grainger has lots of stores where you can pick up will call orders. You do need an account, but last I knew, it wasn’t hard to get one. I think they’re proof of having a business could be satisfied by a business card. Credit was established by paying cash for the first order.
Checker Plate Kings!!!
can you make the embedded videos fullscreenable?
Not that I know of… I’m afraid you have to go to the YouTube page to do that
it’s actually really easy. just make sure the allowfullscreen keyword is in the iframe tag.
They go full screen for me when I click on the full screen button. I’m using Firefox if that fact is worth anything.
it seems to only affect the HTML5 player, not the flash one.
The name: Wooble Dooble
Upgrades: All that was mentioned by you guys. Also maybe: Onboard Raspberry Pi Computer for all kind of stuff + Beamer (maybe for emulated games to play them on a wall). A Camera on the front to record stuff. Many LEDs and stuff to make it look awesome. It’ll look like a giant RC car? Make it one (obviously it should be possible to deactivate the whole system from inside the car). Maybe make the whole car amphibical – that’d be damn awesome.
The speed controller we have actually has serial output which is pretty cool — you can get live data about the motor, battery, voltage, current, everything — I think the program is only for windows though…
I like your ideas! I had a silly one yesterday… Turning one of the main contactor relays into a hood ornament — and you can control the coil voltage with a potentiometer… i.e. while it’s running you can make giant sparks between a pair of consumable electrodes!
I can’t remember of funny things to add, but i can give some tips, watch out for the tire size.. big tires can get you low speed and aceleration. On the other hand, match tire specifications with top speed tire limit.. blowing a tire would not be funny in a “not so secure car” like that.
That said, i think a pair of lights for night ride you be nice, leds or not, and a fancy night rider red light boucing in the hood would be funny.
Deppending on the autonomy, and the vibration you could thing about a solar pannel to extend the e-bug autonomy..
add some sort of meaty servo that can engage on the steering, and make the whole thing remote controllable.
Must-have feature: Configurable engine noise.
Electric vehicles are unsafe in traffic because people don’t hear them. Having an ‘engine noise’ projected outward based on the speed would solve this. Since it would be generated, you can create something a lot more desirable than a standard engine though. These two suggestions are not optional, and must be implemented:
– Jetsons car noise. Obviously pitch coupled to speed.
– Walking/trotting/galloping horse, depending on speed. Bonus points for neighing when you hit the horn.
If I had a Tesla S, I’d want the same feature…
EV’s are no less safe than an IC engine because they are quieter. Modern vehicles are so well muffled anyway the tire noise and air passing over the vehicle is actually louder than the engine. My step mother drives a Mercedes SUV with one of their “Blue TEC” clean diesels. I have to walk up and put my hand on the thing to tell it’s idling.
I’m all for simulated engine noise, it makes driving simulations more fun, but don’t give nanny states one more reason to add red tape to the electric vehicle market by saying we need noise makers when the real problem in unobservant drivers and pedestrians.
“When I put my foot down I want people to think the world is about to end!”
Disagree. I mean, sure, when cruising along at 50km/h, tire noise outstrips a modern car’s engine noise. Inside the car, definitely. But cars navigating through pedestrian-loaded streets tend to be relatively high-rev, and without much tire and wind noise.
I’ve been snuck up on by a Prius more than once. Where with a non-electric car I’d have stepped aside absentmindedly to let the car pass, I just don’t notice cars crawling along on electrics. Same with electric scooters/mopeds. People drive and ride as if room will be made for them, but it’s not, because people don’t hear them. And that makes them less safe.
I should point out that I’m in the Netherlands, and ‘in traffic’ means being around a lot of bicyclists and pedestrians a lot of the time.
I drive a Nissan LEAF and I have managed to sneak up on lot of people (both intentionally and unintentionally) Both drivers and pedestrians are going to have to change their behavior as these things become more common. I just wish I could have the same expectation for the wildlife out there. Critters just don’t hear you and run away as soon as they did when I drove my relatively loud Trans-Am. Those few seconds can make all the difference between life and becoming a squished mat on the road.
…YES!
I wonder if such a thing exists (configurable horse walking/trotting/galloping…) I know there are devices you can plug into your cigarette lighter in your car that can sense your engine RPMs and then put out whatever engine noise you want…
Any ideas on how I might make one? It’ll be easy to control — the accelerator pedal is tied directly to a 10k ohm potentiometer, so you can just tie the audio off of that…
To me there’s only one engine sound to have. TIE FIGHTER!
As to design, car engines change sounds based on RPM and engine load. Volume increases with load and pitch increases with RPM. Load is very easy to measure in an electric car as it’s just the motor current.
If you want to emulate a petrol engine, you’ll need to pretend to change gears, which will sound strange if it’s going to the redline every change with low load.
Tie Fighters and Jetsons cars don’t have gears though, so they luckily would be easier to design (increase volume with load, increase pitch with rpm).
I converted a Honda Odyssey (19hP) engine to a 54 hp Yamaha snowmobile engine. Holy bazooka does this thing fly. With an electric motor and instant torque, you may end up popping wheelies, so wheelie bar is in order.
Names:
Zipster
ZipSpeed
ZipRod
eRod
Great project. Looking forward to seeing a video of it in action.
Mike
Name: Thunder Cougar Falcon Bird (obscure Futurama hovercar reference)
Mods you should do:
* Aerodynamic fibreglass body.
* Tie Fighter sounds.
* 360 degree rotary nerf turret.
Suggestion: How about a huge quantity of super-bright arduino controlled LED’s all over the unit. You can never have to many LED’s …..Right??…… :-)
The great guys at EVTV ( http://store.evtv.me/ ) have some great products including good priced production Li-ion batteries and discontinued surplus. (Lots of other great stuff too) They also put out rather amusing and informative weekly youtube videos. Anyone interested in EVs should DEFINATELY check them out. :-)