Farm Utility Vehicle

[TomSr]

I am planing on building a farm utility vehicle. I should say up front that I have follow this forum for several years and been a member for a couple years but seldom post. Dont have much to say. I find almost all comments helpful and mostly to the point. So this is my choice to bring this dicussion.

To give a little background. I have 12 acres on top of a mountain in NW Arkansas. (Ozark Mountains) Right now I use a john deere L145 riding mower to pull a trailer up and down the hills from my shop and house to my barn(Rabbit House),(I raise rabbits, have over 400 right now). I haul feed and firewood and various equipment and material to assist with my work. Sometimes I haul fence wire and post.

I know everyone will tell me to purchase a 4 wheeler. I dont want to. I have an old 18hp Sears mower. I plan to tear the mower down, extend the frame. I am going to remove the motor and go electric. I have the batteries already. What I want to do is have a bench seat right up front with batteries behind the seat, then behind that have a dump bed with the follow dimensions. Dump bed: 4' X 5' Total vehicle: Approximately 9' long and 4' wide. That measurement is from the back of the dump bed to the front bumper. I think the overall frame would be around 7 foot long X 3' wide.

I am looking at electric motors and tread mill motors come to mind. They are 2.9hp DC motors and a couple of them might do the job.

I am just in the planning stages so any thoughts, ideas and input would be greatly appreciated.

 

[smstonypoint]

Tom,

No thoughts -- just a question out of curiosity.

How do the treadmill motors stack up against the motors used in electric golf carts and electric UTVs horsepower-wise? It seems to me that your vehicle is going to be quite heavy, especially if the dump bed is loaded.

Steve

 

[Soundguy]

my only thoughts are the drivetrain.. how will it hold up to the extra strain.. and tire size.. going bigger? if not you may have traction problems.

look at speed vs torque. keep in mind that tranny on that mower is made to be coupled to a pretty fast engine, even though it is pulleyed down a bit..

soundguy

 

[impdaddy]

go to Plum Quick Motors Forum. They sell upgraded and refurbished electric motors. The guys on that forum are as helpful as the dudes here. :thumbsup::thumbsup:

 

[TomSr]

Thanks for the quick replies.

I dont know how the treadmill motors compare to golf carts. I will be checking to see how they do compare. That is one thing on my list. I dont need a lot of speed but will need pulling power at low speeds.

I plan to change the drive train on the mower to a chain drive. I think I can do that because of the slow speeds of the motor.

Thanks for the referral to the other site I will check them out.

I will post pictures and more as I move along on this.

 

[Rod in Forfar]

Have you considered starting with a golf cart? The batteries will be the big cost in your project and you might luck onto a good set in an older cart as well as a ready-made power train and chassis for your modifications. 36V golf carts are cheaper than the higher voltage electric models. I'd cruise eBay for a week or so and see what they have.

 

[Soundguy]

probably pull better also.. and be more side to side stable than a rider mower. rear axle will be FOR SURE be a better setup

I have a farm CUV vehicle.. it's essentially a gas powered golf cart with a dump bed. love it.. pulls a 4x8 trailer fine.. has a receiver hitch .. etc..

 

[czechsonofagun]

Search TBN, this British gentleman build an electrical tractor from a scratch, he posted detailed pictures and descriptions.

 

[Craig Clayton]

Sir
I am an electrician and have a similiar idea to build an electric garden tractor. The problem is the cost and design to build an electric controller. As stated above I would use an electric golf cart and rework the body, because it is only angle iron , sheet metal and a seat.
Craig Clayton

 

[ToadHill]

I used to work for a company that built traction motors for electric street cars. Keep in mind that if you plan to use more than 1 motor to drive the vehicle that you need some method to syncronize them or the different torque from each motor will tend to drive one wheel faster than the other.

This result is the vehicle wanting to steer itself in the direction of the motor that is turning the fastest.

 

[forester2]

Won't there be considerable power loss w/ either a belt and pulley or chain and sprocket drive? Golf cart will also give a suspension system for a better ride.

 

[TomSr]

Thanks for all the thoughts and ideas. I haven't posted since yesterday as I have been reading and studying various sites that some of you sent me to and there led me to others.

I think now that the treadmill motors may be to small. I think a golf cart will be to big. I want something about the size of my John Deere L145 riding lawn mower but longer and more utility. I think I want to be able to haul feed, fence post and wire, rabbit litter etc.

I am going to attempt to draw what I think I want to do and most it for more comments and ideas.

I also want to use as much from my farm as I can without buying something unless I have to.

JPR3 on the 6x6 sites converted a 6 wheeler to electric using sprocket and chain that he later changed to belt. I am thinking that is the way to go and one motor is a must to eliminate problems.

Again I am planning and thinking now so any and all thoughts and comments are good. I have thick skin and a hard head and sometimes I am slow so you have to say it more than once.

 

[Soundguy]

Sir
I am an electrician and have a similiar idea to build an electric garden tractor. The problem is the cost and design to build an electric controller. As stated above I would use an electric golf cart and rework the body, because it is only angle iron , sheet metal and a seat.
Craig Clayton

it's doable.. but why reinvent the wheel.

I've built a motor controller for an electric utility vehicle with a 5x5 circuit board I etched myself and a fist full of irfz40 mosfets... but there is comercial stuff already on the market.. no need to build a PWM to do the same job..

soundguy

 

[TomSr]

Ok, need some help here. I have 12 Monolite 12vfat75 batteries. They are 12v 75ah/8h to 1.75vpc @ 77F. how long will they last if I configure them to 48volts pulling 100amps. Now this question may show everyone how little I know about this. I am ask just a general answer we talking about 5 min. 1 hr 5 hrs or what or maybe I cannot even use them. They are telecom batteries.

 

[teg]

Peukert Number Battery Life Calculator

Use the calculator above but off hand, very rough guess, pulling a number out of my butt... 15-20 minutes give or take. Those need a perfect charge cycle. ...with a really good charger.

http://www.battery-usa.com/Catalog/12FAT75.pdf

Are these new batteries or were they used? They can be (don't know a better term then) destroyed... if you over charge them.

 

[TomSr]

Won't there be considerable power loss w/ either a belt and pulley or chain and sprocket drive? Golf cart will also give a suspension system for a better ride.

I dont think there will be much power loss. I dont think a direct drive is practical but what do I know, thats why I am asking so many questions.

 

[teg]

We have an '85 Voltswagon Rabbit (96 volts total) It's called the "Lead Sled". I only use 2nd gear around town. Electric motors have plenty of torque, if that is what you are worried about.

 

[TomSr]

We have an '85 Voltswagon Rabbit (96 volts total) It's called the "Lead Sled". I only use 2nd gear around town. Electric motors have plenty of torque, if that is what you are worried about.

What are the specs on the motor you are using.

 

[teg]

My motor is one that you would not want to use... at least not for this project. You'll need to size the motor for your vehicle... (I don't think you'll need one to do 60 mph) but here are the:

Motor details: Motor, Advanced DC #FB1-4001, 9.1", single shaft

The car: 1985 Volkswagen Cabriolet