E12 Puller

dh1

Electric Tractors . from Markham Ont. Canada
Staff member
Moderator
#1
I have s GE garden tractor model E12,
Had it for a while now and decided to.make it s pulling tractor.
The idea is to use 2 snow blower motors, 2+1/2hp each, feed them with 72volts, originally ran at 36volts. Use a chain drive and take it to the pulls.
I have moved the front axle forward.
Hade a hub modified to mount 2 sprokets on it.
Shortened the rear of the frame to move the hitch closer th the rear axle.
And widened a set of rims for
26-12×12 tires. 20190412_192610.jpg
 

Cvans

Tractorologist
Senior Member
Member
#5
I don't seem to have any problems uploading photos. Not really into tractor pulling but sure would like to see a video of yours doing it's thing.
 

chieffan

Tractorologist
Senior Member
Member
#7
Doubling the voltage for very long could fry the motors. 36 to 72 is a lot different then putting 12 V to a 6V starter for 5-7 seconds time. Be interesting to see how they stand up. Good luck.
 

dh1

Electric Tractors . from Markham Ont. Canada
Staff member
Moderator
#10
I don't think that it matters if 1 motor wamts to turn faster than the other.
They are geared 1to1, both turn together, get fed the same voltage and are under load.
1 motor is not going to slow down the other.
 

chieffan

Tractorologist
Senior Member
Member
#13
I've seen tens of thousands dollar spent to get two identical dc motors to load share properly. Without proper control they will fight each other.
Ever seen a freight train with 3 or 4 engines on it, or even 2 on point, one in the middle and two running DP? They are not running exactly the same amount of torque but they run that way half way across the country and back several trips and no issues. They all share part of the load but not equally.

Or how about a vehicle stuck in the snow, can't move but two guys help by pushing on it get it out. No equality of power there either but it works.
 

Toomanytoys84

Aaron
Senior Member
Member
#14
Ever seen a freight train with 3 or 4 engines on it, or even 2 on point, one in the middle and two running DP? They are not running exactly the same amount of torque but they run that way half way across the country and back several trips and no issues. They all share part of the load but not equally.

Or how about a vehicle stuck in the snow, can't move but two guys help by pushing on it get it out. No equality of power there either but it works.
That's not an apple to apple comparison. You have 2 motors mechanically locked together.

You have 2 DC motors wired parrell Connecting them in parrel voltage will be the same but current will be shared between the two motors.

I'm no electrical engineer but I have worked on many multi motor belt drives. One motor is set up as the master motor the rest as slaves. The master says to the other motors ok guys I am going to be running 3600 rpm you guys need to help keep me there.

I don't believe a dummy curtis motor controller is going to manage that.

Also worked on DC locomotive with a 100hp drive motor on each end. Controlled with a saminco drive. When this was in development one motor would do all the work and the other motor just sat there basically doing very little. It took people much smarter than me to get the two motors to work together and share the load.

I'd say the end result of this is that one motor will burn up. Not immediately but over time one motor is going to be taking the load.
 
Last edited:

Cvans

Tractorologist
Senior Member
Member
#15
Aaron I can see that happening in parallel? When we ran conductors in parallel they had to be almost exactly the same length or one set would try and carry the whole load. If one of your motor shows more resistance than the other I would think things might get a little toasty.
Really hope dh1 carries through with this project and proves us wrong. This is what makes projects like this so interesting.
 

Toomanytoys84

Aaron
Senior Member
Member
#16
Aaron I can see that happening in parallel? When we ran conductors in parallel they had to be almost exactly the same length or one set would try and carry the whole load. If one of your motor shows more resistance than the other I would think things might get a little toasty.
Really hope dh1 carries through with this project and proves us wrong. This is what makes projects like this so interesting.
I don't want anyone to think I am trying to put down his project. I'm just throwing in my 2 cents on what I think.

I'm all in for innovation and trying to build something new and cool!
 

dh1

Electric Tractors . from Markham Ont. Canada
Staff member
Moderator
#18
I have a 36volt 200amp controller.
My idea if I can get it to work, is to run with the controller at 36volts to move the tractor around and start the pull, once I get going and I feel the tractor start to slow down a bit I hit a switch that turns on a contactor, bypasses the controller and applies 72 volt direct to the motors and run till the tractor stops.
Each motor will get 72volts and draw what every they can and what ever the batteries can deliver.
These motors came with a 105amp circuit breaker, I expect then to draw double that or more.
So 105 x 2 = 210
210 × 2 (motors) = 420amps in theroy if I'm right on this. ???

Now I'm working on the hitch and wheelie bars.
 
Top