Electric tractor

[bill177]

I have been reading up on the subject of electric cars - the kind you do the converison work on yourself. All this got me thinking about doind a conversion on a tractor.

For short jobs - which most of mine are - I think there might be some fire amongst the smoke and mirrors of the battery operated technology.

I till my garden in about 30 minutes (30 x 70). That is twice a year. I use the bucket loader a couple of hours a week for various "stuff" moving. Weekly trips to the burn barrel. Even snow moving takes me no more than an hour at a time.

All told, I probably put a hundred hours on the tractor a year. Again, mostly short jobs.

Finding a runout tractor around here is not a problem. They can be found all over the place. Engines are shot and there is no interest in rebuilding them.

Well, enough air castles - anyone else ever give thought to a project like this?

 

[2manyrocks]

Apparently, it has already been done.

Electric Tractors on Small Farms

 

[ToadHill]

When I worked in industry the company I worked for made electric motors, both AC and DC. Many of the DC motors were what were called Traction motors. They were used in rapid transit rail systems and both powered the rail car and acted as the brakes.

If they could power these heavy cars it would stand to reason they could be made to power a tractor. The battery pack could certainly add to the weight of the machine.

Many of the very large earth moving machines that run diesel engines actually have traction motors driving the wheels and the diesel engine powers a DC generator.

 

[EddieWalker]

LaTourno was a big time, heavy equipment builder back in the 40's all the way to today. His company still makes some of the larger mining equipment there is. He invented hydrualics on a dozer blade and the self propelled belly scraper. In his modifications and improvements to the scraper, he came up with putting electic motors at each wheel. He said that the electric motor has so much more power then a diesel engine, that it was the logical thing to do. Of course, that was before modern hydraulics, and I don't know anything about electric motors. He used the diesel engine to generate electicity and the electric motors to turn the wheels.

The problem I think you'll have is getting electric motors big enough to do the job and then having enough electicity to power them.

Eddie

 

[IXLR8]

My neighbor, when I lived in Conn., had 2 GE electric lawn tractors, they were totally electric, 4 batteries I think, he loved them. I have no idea if they had more tractor ability than just mowing lawns, no idea what happened to them, haven't seen him in 8 years.

 

[Wayne County Hose]

Interesting idea. The one big drawback for you is the limited use. The batteries in a high draw machine such as this are made to be discharged down to 80% discharged, rested 8 hours, then charged. Your application would be very similar to a forklift application. For short uses, less than 4 hours a day, you are far better off with an IC power. You would destroy a set of batteries in a couple years using them the way you would like. The other alternative is to use an IC powered generator to power the motors, which defeats the purpose of installing electric motors in the first place.
Forklift electric motors would have plenty of power for something like this. Just go into one of those warehouse clubs like Sam's club and watch the little 3 wheel electric forklifts lift up 3,000 lbs pallets, plus they are lifting the weight of the mast which is another 1500+ lbs. And these are the little 3 wheelers, you should see the 4 wheelers.
Unless you have quite a bit of knowledge in electric motor controllers and their technology, and a place to access the parts pretty cheap, I wouldn't even bother.
I had entertained the idea of building an electric jeep years ago. I have the schooling and the parts readily available for almost nothing. I determined that even for me it was a huge project and abandoned the idea.

 

[js5020]

I have given some thought to this idea myself, how big a machine are you thinking of converting? A major drawback with any electric vehicle is the costs involved in the conversion, new motors, controllers and batteries are expensive, basically all the expenses are "upfront" before the machine can be used. The big issue really is the battery,, or fuel, it's a major cost as your essentially buying 5 to 8 years of fuel upfront, not as you use it. Batteries get expensive, even a pack made of 4 six volt commercials for 24 volts is gonna run in the area of $400 or more and a charger will have to be added to that cost.

Run times for the equipment obviously will depend on power consumed, and unlike gas/diesel once the power in the battery is consumed ya can't just tip another can into the tank it will take some time to recharge. But you can get around this problem, the solution is easy,,, but involves more cost, have another pack of batteries and change the pack out. With enough battery packs and adequate charger capacity the machine could be run 24/7 if that was your goal.

Components can be expensive if purchased new or if you have some knowledge and adaptation skills cheap, there are many sources of cheap parts , depending on what your looking for of course. The system can be simple or complex, depending on your needs, and of course the more complex the more cost will be involved.

I'll have to find the links for some of the conversions that are out there on the web, they range from conversions to full scratch builds.

 

[jeff_jeff]

Here's a link to plans for an electrict gardern tractor - Its on my future projects list.

Home built (DIY) small electric buggies and go kart plans - DIY 1300 Watt Yard Tractor.

 

[Wayne County Hose]

Here's a link to plans for an electrict gardern tractor - Its on my future projects list.

Home built (DIY) small electric buggies and go kart plans - DIY 1300 Watt Yard Tractor.

That little thing isn't worth the scrap it's made out of.
First of all, the drive wheels have about 1.5 hp each after losses, it would barely climb a small grade.
Second, they have no provisions for turning. No, I don't mean the steering wheel. On a dual drive motor truck, you need to have provisions to slow down or stop the inside drive wheel when turning. Kind of like what spider gears do in a rear axle. This can be done with either limit switches on the steering or electrically thru the controller with a steering feedback sensor. And I could go on for pages.
Personally, I would have gone with a 36v controller. This way you keep the amps down prolonging the life of all the electrical components. If I were to build anything larger, it would be at least 72 volts. I would go with higher voltages except for lack of obtaining a controller. I know that 72v controllers are easily obtainable, I don't know about higher voltage.
If anyone is interested, some good motor controller companies are Curtis, General Electric, and a fairly new one on the scene is Danaher. The cheapest and most popular are the Curtis units. GE has gotten their butts kicked lately by the other 2. I've worked on some of Danaher's stuff, DC power converted to AC to power the motors. Their stuff is very reliable, but pricey too. Also, AC drive is the way to go. Most forklift manufacturers have converted over to AC drive and lift systems. Some Forklift manufacturers don't even make a DC motor anymore. I can set-up an AC powered forklift to smoke the drive tires. DC trucks could never do that. Pretty funny seeing an 8,000 lb. electric forklift smoking the tires.
Ugh, now you guys have me thinking about building an electric powered vehicle again.

 

[keeney]

I was noticing that many of the newer Zamboni units being put into service are electric. Being used almost exclusively indoors for 15 minutes every hour or so, they are a perfect applicaiton for electric power.