[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: (ET) Somebody needs to be shocked!!
Dean has the right ideas in his listing.
Here are a few of my own.
1) Strip the tractor of everything that is not needed.
2) Do off vehicle charging.
3) Remove any accessories that is not required for traction.
4) beef up your breaker circuits and cables
5) double up your belts or go to the toothed belts as discussed
6) Remove your original batteries and replace with smaller, lighter, lower
Ah batteries
(remember this is a short term event you do not need hours of
capacity only minutes)
(I ran into the same thing with designing electric dragster, you can
get the
weight really using smaller batteries)
6) Place all your batteries so as much of the weight as possible is on the
rear tires.
7) Then mount the sled hitch as low as possible (this is my personal
feeling
which is different from Dean's). The downward force (weight) on the
hitch
will be the same no matter where it is mounted, but pulling force from
the
hitch if mounted above the center of the axle will be a moment arm and
will
help raise the front end off the ground which is wasted energy. Mount
as low
as possible for stability and to keep the front end on the ground then
less weight
is need in the front and more can be used on the rear tires to provide
traction.
Here is a link to technical papers I wrote. Look for the paper regarding
the electric dragster. I believe it is the second paper down on the page.
http://members.aol.com/_ht_a/dreutermi/TechPapers.htm
Go to page 6 table 2 for the call-out of the batteries I used in the study.
They were about 13 lbs a piece.
That is my two cents on the mater. I envy you all that get to play with
your EV's. I am still trying to find the time in my wife's honey do list to
finish building mine.
Dave Reuter
"Dean A.
Stuckmann"
<dstuck@lakefield To
.net> GE e-mail Elec-trak
Sent by: <elec-trak cosmos phy tufts edu>
elec-trak-bounces cc
@cosmos.phy.tufts
.edu Subject
[RMX:##] Re: (ET) Somebody needs to
be shocked!!
03/24/2004 10:51
PM
I dug up an old posting that I had made a while back...
I have entered my E15 in two pulls over the years. Both with poor results
I¹m sorry to say. It was still a crowd pleaser though because most people
have never seen an ET work. I know that different areas have different
types of pulls. In Wisconsin we pulled a machine that has a skid pan at
the
draw bar end and wheels at the tail. As you pulled, a weight would move
from the wheeled end, towards the sled end which makes the machine tougher
to drag along.
Now for the problems.
1. The ET (and I) are heavy which put me in a class with 16-20 hp
tractors.
2. Speed is you friend in this type of pull you need to keep the
sled
moving to minimize friction. This is a problem with an ET. I tried my
first pull in the lowest range. The meter never got in the yellow but it
was way too slow to keep the sled from sticking to the ground so I ended up
spinning my wheels very early in the pull, even with the front wheels
lifted
off the ground. The second pull was better in the second range, but I
stripped hood of the tractor down to make the lowest weight class I could.
Problem with that is that you can¹t add weight to the tractor where you
want it. The meter was in the red at wide open throttle so I backed it down
till it was at the high end of the yellow, again with the front wheels
about
a foot above the ground. The farther I pulled the higher the wheels went.
The official stopped the pull for safety reasons, but I was still a long
way from the leader¹s distance. I don¹t think that you could pull in the
3rd range.
3. I think that the ET would have easily pulled the winning tractor
away in a back to back pull because then the ET¹s torque would never allow
the high powered tractor get the speed it needs to be effective.
I heard that E20s did well years ago but I never saw one pull.
Here are some tips.
1. Build a hitch that is as high as the rules allow. This helps lift
the sled and transfer weight to the drive wheels. Also keep it as close as
possible to the rear wheels to have more control of the weight transfer.
2. Make sure the drive belts are tight.
3. Make sure that your battery connections are clean and secure. You
will have a high load them for a while.
4. The E15 was light in the nose for both of my pulls. I would add
any
weight that you could to the front of the ET.
5. If you pull with turf tires, don¹t get the tire pressure too low
because the center of the tire will buckle up and you will only be pulling
with the outside of the tires.
6. Most important - do some testing by pulling a car or truck, with
someone slowly applying the brakes on a similar surface as the track.
Block
the chain down to the ground on the towed vehicle to mimic the action of
weight transfer as the load increases. Be prepared to pull the track
distance. I was looking at trying to pull 200¹ and it seemed to take
forever to get to down the track. You start wondering if you will trip a
breaker or something.
7. If I was going to do it again, I would go a bit wild and strip the
tractor to get in the lightest class I could. Replace the 6 batteries with
3
(or 4) marine batteries. Take out the charger and lift. Maybe alter the
drive pulley size if I found myself wanting to be between ranges.
Good luck and keep us posted.
Dean A. Stuckmann
> Hi Dave and all, I agree. It would really be fun to
> hear what happened if you showed up. Have you thought
> of joining the group, just to legitimately be able to
> join in the pulls? I say go for it.
>
> Dave, I apologize for not getting back to you after
> sending me the relay. I am still working on getting it
> going.
> Dan Eyk
> E-15
> Vancouver, Wash.
>
> --- daveb <daveb seanet com> wrote:
>> oooooh this is just too good to pass up. I hope
>> you or someone can
>> "innocently" show up with this little electric
>> tractor "that thinks it can"
>> (as in the little locomotive kids story)
>>
>> dave
>> seattle
>>
>> --
>> Open WebMail Project (http://openwebmail.org)
>>
>>
>> ---------- Original Message -----------
>> From: "T Humphrey" <thumphrey mynra com>
>> To: <ev listproc sjsu edu>,
>> <elec-trak cosmos phy tufts edu>
>> Sent: Tue, 23 Mar 2004 17:31:13 -0500
>> Subject: (ET) Somebody needs to be shocked!!
>>
>>> HeHeHe
>>>
>>> Read this response to my asking if my Elec-Trak
>> would be welcome
>>> at the garden tractor pulls...
>>>
>>>
>>
> http://groups.yahoo.com/group/cnygardentractorpullers/message/184
>>>
>>> --- In cnygardentractorpullers yahoogroups com,
>> "thumphrey"
>>> <thumphrey1@e...> wrote:
>>> Hello Tim, You are welcomed to come to the meeting
>> and learn more
>>> about our club. You do not have to join that day
>> if you choose not
>>> to. Your thought on your electric puller is
>> intresting. But I
>>> personally don't think you would have much of a
>> chance. If you have
>>> never pulled before, you would learn alot by
>> coming to the meeting
>>> and asking people questions, on what it takes to
>> put together a
>>> puller. If we can help you more we would like to
>> hear from you.
>>> Otherwise hopefully we will see you at the
>> meeting. tim
>>>>
>>>
>>> Stay Charged!
>>> Hump
>>>
>>> _______________________________________________
>>> Elec-trak mailing list
>>> Elec-trak cosmos phy tufts edu
>>>
>>
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>> ------- End of Original Message -------
>>
>>
>> _______________________________________________
>> Elec-trak mailing list
>> Elec-trak cosmos phy tufts edu
>>
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>
>
> =====
> Daniel Eyk
> Vancouver, Wa.
>
> Electric S-10 project
> E-15 project
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Finance Tax Center - File online. File on time.
> http://taxes.yahoo.com/filing.html
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak