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A DC motor
produces rated torque at low speed until base speed. After that, weakening
the shunt field raises the speed but torque drops off.
A typical ICE
builds torque with speed and doesn't produce rated torque until near rated top
speed.
Gear ratios
multiply torque.....if it's lower, torque goes up. 2:1 means
torque multiplied by 2 and speed is 50%. HP same.
I searched for
some articles describing that and found one below that is
interesting.
Do you really think you need (2) motors.
I had always thought that the number designations that GE
Elec-Trak used was suppose to be equivalent Horsepower.
i.e.; GE E15 was equivalent to a 15 HP gas tracer, GE E20
equivalent to a 20 HP gas tractor.
Others please comment.
Dennis
Elsberry, MO
Geof and all,
Speaking of converting from ICE to electric, I
could use some advice and/or tips on doing something similar myself.
Ever since I met Shawn Lawless last year at the Louisville Lawn Expo and saw
his ZTR, I've wanted to try something similar.
I recently bought an older (late 80's maybe)
Model 411 Grasshopper with intentions of converting it. It currently
uses an 11 hp Briggs (horizontal shaft) driving two Eaton hydro units that
then drive the wheels through 13:1 double chain reduction systems.
I'm thinking about using two E15 drive motors and
two Alltarx units to drive them. Without a lot of major changes, I think
I can position the two drive motors parallel to each other with one pointing
east and the other pointing west. I'll mount the smallest possible
#40 sprockets to the output of each motor to drive the first 4:1
reduction.
One possible problem I'm wondering about is that
one motor will be turning it's normal "optimum" direction and the other will
be essentially running in reverse while the mower is going forward. And
visa versa for when backing up.
Do I need to consider modifying the brush
position/location or even possibly the field winding connections such that
when going the predominate forward direction, both motors are in "optimum"
direction mode?
With the Briggs engine gone, (this is a front
mounted deck Grasshopper with the single tail caster wheel) I figure there
ought to be plenty of room to finally do something with those 60+ Saft BB-600
NiCads I've had for about a year now.
I figure I'll replace the current shaft driven
36" deck with a 42" ET deck and that swap shouldn't be a big
deal.
Any of you guys got any suggestions or words of
wisdom for me?
Mike in KY
----- Original Message -----
Sent: Tuesday, November 21, 2006 6:38
AM
Subject: (ET) Electric Tractor
Conversion Update
Hello All
www.electriclawntractor.com
Edmonds Electric says the
Electric Conversion Kids will be ready early 2007 at $2000, (not sure if
that Canadian or American).. I also noticed a 36V to 120AC solid sate
inverter.
I've got a nice little Cub Cadet
just waiting for a transplant.
Geof
Thompson
A-60,
E-81,
ER8-36,
R-36
E-8,
E-10x2,
E-12M,
E-12,
E15x2,
E-20x2,
B-145X2,
C-185,
E-141X2.
I-5
(21)
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