RE: (ET) Elec-Trak Beginner Advice

[Larry Elie <lelie ford com>]

Steve wrote an excellent post, but I'm going to give the counter post....

----------
From:   Steven Naugler[SMTP:snaugler earthlink net]
Sent:   Tuesday, April 13, 1999 9:38 PM
To:     KevinC927 aol com; elec-trak cosmos5 phy tufts edu
Subject:        Re: (ET) Elec-Trak Beginner Advice

;Kevin....
;    I think that you want a large frame tractor, preferably an E15 or E20.
;While an E10 small frame can theoretically have the large range, the large
;frame tractors have a wider deck, 42 in vs. 36 in.  There are also more
;attachments for the large frame tractors.  Also, the small frame tractors 
do
;not have wound field traction motors.
;    Why an E15 or E20 vs. the E12, E12S, or E14?  I'll get to that in a 
bit,
;but first some warning about some of the permag (permanent magnet field)
;motored tractors.  The E12 has a permag traction motor known for having 
its
;field magnets weakened.  I've been told that E14s, somewhat rare, also 
have

I have heard that too, yet I have an E12 with a field magnet decidedly NOT 
weakened.  
A service person told me that, like the mower deck motors, which are 
always PM 
motors, the only way to weaken them is to apply 150% of the rated voltage 
to them.  
This if 54 V, which I believe is unlikely.  You didn't mention that an E12 
has a front 
mounted mower, and electric lift, like E15/E20, while an E12M (and E8 and 
E10) has 
a belly mounted mower.  Another difference is E12 has a single drive belt, 
while 
E15/E20 have two.  That might not sound important, but I have spun a belt 
plowing 
snow.  It might not have been tight, or perhaps it was just cold, but the 
dual belts 
probably wouldn't have spun.

;permag motors.  An E12S is an E12 with a wound field motor, better, but 
not
;as good as an E15 or E20.  Unless you get a real deal, you want a wound
;field motor.  And while you can convert a tractor with a permag motor to a
;wound field motor, these E15 and E20 tractors with wound field traction
;motors are just not that rare.
;    Here is why you want an E15 or E20.  The E12, 12S, and 14 have only
;three electrical forward speeds.  All of the large frame tractors create
;motor speeds 1 and 2 by reducing the battery voltage by passing the full
;armature current through large resistors.  Very wasteful.  Speed 3 has the
;full battery voltage applied to the traction motor armature.  Speeds 
4,5,6,
;and 7, and also speed 8 only in the E20, are gotten by reducing the field
;voltage while the armature still sees the full battery voltage.  (When 
field
;voltage, hence field current, is reduced, motor speed increases and motor
;torque decreases.)  Reducing field voltage via resistors, while wasteful, 
is
;still only about 1 to 5 % as bad as the waste you get when reducing speed 
by
;reducing armature voltage via resistors.

That's all very true.  Yet I very rarely do not just punch the speed on 
full in any gear 
and just push the cruse-control button.  Since I don't run down the 
batteries in 1.5 
to 2 acres (if it is REALLY charged), I don't see it as a problem.  The 
creeper speed 
would be nice if I had a tiller, but I don't.  The other problem is the 
E15 and E20 are 
a LOT more complex as far as the number of wires and relays... the E20 
being the 
most difficult to work on.  I am told that the New Idea versions of these 
use different 
relay combinations on modules and are better, but I have never looked at 
one.  If 
everything is working when you buy the tractor, then this isn't a problem, 
or if you 
like working with wiring it wouldn't matter much.  The E20 has a nice 
foot-pedal 
control for speed, like a hydrostatic transmission on a gas garden 
tractor, which 
would be dynamite for plowing snow.

;    What does this all mean.  With the 3 speed E12, 12S, and 14, your 
speed
;selections are such that you may frequently run in the wasteful speeds 1 
and
;2.  3 electrical speeds are just not enough.  With the 7 speeded E15 or 
the
;8 speeded E20 you very seldom need speeds 1 and 2.  The E15 and E20 are 
much
;easier to operate in an efficient speed, and with more speeds to choose
;from, just easier to operate.

You missed one.  E15 and E20 usually have a heavier cast-iron front axle, 
while I 
have only seen one on an E12.  This doesn't sound important, but in a 
heavy pull, 
the front end gets light enough that you can't steer an E12.  The extra 20 
or 30 lbs. 
should make a difference, but I haven't worked with one to be sure.  Also, 
E15 and 
E20 usually have wider tires and rims, and since the overall weights are 
similar, 
should not sink into soft earth as easy.

;    Where to find one?  If you are near Delaware or eastern PA I might 
know
;where to find one.  Otherwise you are better off looking locally.
;    Hope this all helps.

;Steve Naugler

Yes Steve, I'd like an E20, preferably a New Idea, but I'm not displeased 
with the E12.  
None are really bad products.


----- Original Message -----
From: <KevinC927 aol com>
To: <elec-trak cosmos5 phy tufts edu>
Sent: Monday, April 12, 1999 10:36 PM
Subject: (ET) Elec-Trak Beginner Advice


> Hey all,
>
> I just found out about this list on Sunday and here I am.  Great idea,
thanks
> to Rhett George.
>
> I am looking to replace my old smelly, noisy John Deere 140 with 
> something
> more elegant.  The primary mission is mowing slightly cultivated weeds.  
> I
> have about 1 acre that needs attention weekly in the Spring and biweekly
up
> until November.  Any suggestions from users with similar circumstances?
>
> Also, where might I come by one of these that you suggest?  I am
moderately
> skilled with electrical devices and could do repair.
>
> Thanks,
>
> Kevin Carter
>