Re: (ET) E12M - Tractor Pull

[Bfayette aol com]

This is all very interesting.  A couple of thoughts:

I would try mounting 3 batteries in the front and 3 in the rear.  Or 
better yet, 4 in the rear.

I would also go to a chain drive.

If the rules allow, I would use 2 motors. Or maybe a bigger motor, like an 
aircraft starter or something.

This technology has been under development for a while for gasoline 
tractors, so they are at or near their peak performance in this 
application.  ET's have just started. There would be a lot of room for 
improvement

Brad


 message dated Wed, 10 Jul 2002 22:48:18 +0000, dstuck lakefield net 
writes:

> I have entered my E15 in two pulls over the years.  Both with poor 
> results I’m 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.
> 
> The ET (and I) are heavy which put me in a class with 16-20 hp tractors. 
> 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 can’t 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 leader’s distance.  
> I don’t think that you could pull in the 3rd range. 
> I think that the ET would have easily pulled the winning tractor away in 
> a back to back pull because then the ET’s 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.
> 
> 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. 
> Make sure the drive belts are tight. 
> Make sure that your battery connections are clean and secure.  You will 
> have a high load them for a while. 
> 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. 
> If you pull with turf tires, don’t 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. 
> 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 200’ and it seemed to take 
> forever to get to down the track. You start wondering if you will trip a 
> breaker or something. 
> 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 
> 
> 
> 
> I’ve been encouraged to enter my E12M in a local garden tractor pulling 
> contest this weekend in Longmont, Colorado.  
> 
> 
> 
> An E20 would be more fun to show off.  I’m a little worried how my ’12 
> might fare and would appreciate any tips or 
> cautionary statements you guys might have.
> 
> 
> 
> Thanks,
> 
> -Dave 

  Brad