Teamster 2000

[Andy Carson]

The part about the teamster 2000 that doesn’t make sense ot me as a PTO cart is that (at least from what I can tell) is has 3 wheels, but only rear two wheels drive the PTO.  That front dolly wheel removes a substantial amount of weight from the drive wheels.  Put a scale under that wheel and you will see how much weight is taken by that front wheel.  Weight is traction, and traction is power for a ground drive set-up.  One would definitely get more power out of a setup without a dolly wheel.  If you had to have a dolly wheel, best put it as far away from the center of gravity as possible.

[Andy Carson]

I did an analysis of the power generated from ground drive systems.  I think this analysis is important and interesting because it may reveal where the greatest improvements can be made.

Obviously, having more traction is always better for generating power.  Increasing traction can be done by increasing weight (which lowers overall efficiency), of by changing tires or traction systems (which may increase complexity).  But how much traction is enough? 

If we assume that we are using pneumatic tires, the coefficient of friction will be from about 0.35 to 0.75.  Tractor type tires on dry surfaces are at the higher end of this range, road type tires on wet surfaces are at the lower end.  Note also that even for a higher efficiency tires, this coefficient will vary wildly from point to point in the field, especially at wet spots.  Still these numbers provide somethins to work with.  This means that if the cart weighed only 100 lbs, it might take only 35 lbf to drag it without turning the wheels if it has road style tires and 75 lbf to drag high efficiency tractor style tires.  I will also compute crawler tread at a friction coefficient of 1.  Some references report crawler tracks as 50% increased over tractor tread (which would give a friction coefficient of 1.1), but I think a friction coefficient of 1 is a better upper limit (even though things like dragster tires go past 1).

A rule of thumb is that animals can pull 15% of their body weight at a steady rate, so 2 1600 lb animals exert a pull of 480 lbf, 3 animals pull 720 lbf, and 4 animals pull 960 lbf.  If the work is ground driving, the wheels need to start spinning and not skid over the ground.  This is the first force I will calculate.

With road tires of wet turf (friction coefficient of 0.35), it takes a cart that weighs more than 1370 lbs to start a “two horse load” with no slippage (480/0.35), a 2060 lb cart is needed for a “3 horse load” (720/0.35), and a whopping 2740 lbs is needed for a “4 horse load” (960/0.35). 

Change to a tractor-style tire and this picture gets more promising.  A 640 lb cart would start a “2 horse load” (480/0.75), a 960 lb cart will start a “3 horse load” (720/0.75), and 1280 will start a “4 horse load” (960/0.75).

Crawler tracks let you start a 2 horse load with a 480 lb cart, 3 horses with a 720 lb cart, and 4 horses would need a 960 lb cart.  Better than the tractor tires, but I have doubts it is worth the complexity for starting a load alone…           

Once the wheels are started, the surface actually travels at half the rate the axles and the rest of the cart do.  Think of pushing on the top of a wheel rather than the back of a cart.  You get a 2:1 mechanical advantage.  This means that once the wheels are turning, they require only half the weight to keep them turning.  That’s only 690-1370 lbs for a cart with road tires, 320-640 lbs for a cart with tractor style tires, and a tiny 240-480 lbs for crawler tracks.  Here the crawler track system seems to be interesting for high power (high horse number) applications, where extra weight might not be needed.

After doing this analysis, I come away with 2 important areas to focus on for greatest improvement.  I think this matches with experiences I have read about using ground drive PTO carts, but those with more experience will have to tell me if these observations seem to match the real world experience. 

1)      Use the highest traction tires possible.  Small gains here make a very big difference. 

2)      Keep those wheels turning!  Locking them up means they are going to be twice (literally twice) as hard to start again.  In the meantime, some tools (like balers) clog up from going forward without running which further increases the force required to start up again.

[gwpoky]

Andy,  I see your point in all these calculations, but the fact still is, these carts have worked in the real world.  Dris Abraham of ProphetsTown and RX Belgians  has used the I&J heavyduty cart with great success on mowers, balers, corn pickers and more, as have many other farms.  My questions here is more the comparison of the I&J style cart to the Teamster 2000 and my main need for this type of cart is the ability to mow a 9 foot + cut as we put most of our hay up loose.   Other application for the three point hitch could come into play down the road.  I know few people with field experience with the 2000 but have chated with Dris extensively on “Rural Haritage” and seen videos  about the I&J (which is currently out of my price range).  I am wondering if the 2000 could handle a three point mounted 9′ mower or is that too much for its three point ect.   Take Care

[Andy Carson]

George, I wasn’t doing these calculations to show that these carts don’t work.  I was meaning to demonstrate the critical points of the design.  The I&J cart actually has almost all the features that seem to be important from these calculations.  Pneumatic tractor-style tires maximize traction.  They yield substantially more power than road-type tires.  On some terraign, this might double the power obtained by car/truck style tires.  The adjustable tongue keeps the weight over those wheels.  Notice no power-robbing dolly wheel on this one.  The weight on this heavy duty cart is substantial at 1500 pounds.  This is very close to the 1280 lbs I calculated to be needed to start a “4 horse load with tractor tires.”  You might notice that the weight of thier “regular” PTO cart, which is demonstrated with a team of horses, is 750 lbs.  Very close to the 640 lbs I calculated for a 2 horse load…  This seems like a well engineered machine that has taken into account the factors that the analysis would predict are critical.  In my opinion, to equal the I&J machine, the teamster 2000 would need to 1) remove the dolly wheel 2) come up with a balancing system to deal with the tongue weigh of a ~1500 lb two wheeled machine and 3) switch to tractor tires. 

Alternatively, a heavy flywheel with a couple adustable one-way dog clutches to let the flywheel spin up without robbing a lot of power, but deliver that power when the wheels start to slip (IE prevent the wheels from locking) might let one half the weight of the whole rig, but that is another topic.

Here’s the link to the I&J site, and no, I don’t work for them! 🙂

[gwpoky]

Andy,

I agree and I would love to buy an I&J someday, but  it is currently our of my budget.   What are your thoughts on using the 2000 to just run a 9′ sickle and as a three point cart?  I may be able to get into this one for $1500  and that’s what I paid for my plane jane Pioneer cart.  Even as cool as the I&J is I think it is about $1000 over priced.

[Andy Carson]

jeesh, for that price I might by it and I dont even know what I would do with it!

I and J shows an 8 foot sickle bar pulled by a team.  That is an improved designed though, and might be 50% improved over traditional designs.  I dont know much about your 9 ft bar, but I might guess 3 horses might be needed to run it.  This is a major guess on my part, others would know better.

I googled the weight of the teamster 2000 as 1400 pounds.  I am guessing there might be 300 lbs on the dolly wheel, which leaves 1100 lbs on the drive wheels.  On dry ground with good tires, I would guess this cart would convert the power of 3 horses. Good tires and ry ground are big factors. If your land is flat, you can always add more weight too, and increase traction.  You might not need it, but weight is an easy mod.  You could shorten the bar too.  Theres lots of posibilies if it does work, and it might without mods. At this price, I see no downsides. I have had that response to some I and J products as well, nice, but not always the nice price.

[gwpoky]

We settled on $2000 and it comes with eveners from two to six and a new, larger,  pump.  It looks a bit ruff now, but it is solid, needs a new front tire and there are chains on the rear tires.  I will post pictures when I get it.   Very exciting!

[Donn Hewes]

That sounds like a great deal.  I think that will pull your mower just fine.  I would love to hear from folks using GD carts to pull balers.  Just curious about how well it works for them; what balers,  number of animals, etc.   If you could encourage some one to make a post here that would be cool.  Good luck.

[j.l.holt]

My post about carts was about taken over by baler and related talk. Might get something from there.

[gwpoky]

Donn,

I have seen the heavy duty I&J pull and JD 336 baler (no wagon) with four and it worked well.  I don’t think it would be a good idea to double windrow.   I am curious myself with this one, I might have to try it just for fun, who knows.   We put up most of out hay loose, but we do bale about 1500 small squares a year.

Take care

[Donn Hewes]

I have seen, and ridden the I & J pulling a JD baler and it worked OK, Not good enough in that circumstance to suit me; but it was at a field days and we may not have had the weight in the tires or something.  I have also seen the GD baler at HPD.  I would really like to hear from someone that bales their hay all summer with a GD cart as I am unsure which carts, and how many horses it will take to make it really go.   I can only speak for my self, but plugging more than once a day would probably be what I would consider not working for day to day use.  That is just me,  I also don’t want a baler that only works with small windrows or perfect hay.

[gwpoky]

Got the “2000” home yesterday, pictures to come.  Anyone one know the best steps to paint something like this?

[gwpoky]

Here is a Picture.

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[Livewater Farm]

same older model and color as the one I  own   you will want to put a hand rail on it and go to work

Bill

[Paulk]

If I were a little closer I would offer to help you, I have a sand blasting and painting business and could make it look new again. I’m in Southern Illinois though.  The best thing to do is get a grinder and wire wheel and go to town on any rust or loose paint.  Then I would invest in a good industrial or implement primer and  paint that will resist the UV rays of the sun and also snow/rain etc.  I only like to do things once so when I paint I try to use the best paint available.  If you have an air compressor you might consider buying a paint gun but if not a brush will work also.  I can say if I have to brush paint anything I usually con the wife into it, just not my cup of tea.

On another note could you take a picture of the rear and the hydraulic drive .  I am going to build a forecart in the near future and am trying to get ideas and decide how to do it.  I originally planned to build a simple forecart but I have alot of three point equipment already so instead of trying to find horse drawn equipment maybe I need to build a cart with three point.   Paulk

 

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