Height of Std Cat1 3PT arm ends.

[jnjpream]

Hi All,

I'm attempting to build a "shim" that raises the hitch points of a SCUT 3PT hitch to that of a standard 3PT hitch while keeping the correct geometry. But I need to know what the distance is from the ground to the center of the drag link pins on a "standard" Cat 1 3PT hitch when the arms are parallel to the ground.

I'd like to get the measurements off of a few different tractors to see how much it varys.

Anybody out there with full size equipment willing to help me out?

Thanks.
Jeff

 

[greg_g]

Presumably you have a Cat 0 or a Cat 1N, and want to use Cat 1 implements. You also need to consider the different toplink pin and lower lift pin diameters between Cat 0 and Cat 1.

But specific to your question, the distance from the ground is not standardized. That's typically controlled by the vertical links anyway. Since the two lower lift arms and toplink move together as one unit, the size of that triangle (and pin diameter) defines the difference between hitch categories.

The attached diagram represents the ASAE Cat 1 standard for implements. Your hitch modifications should be such that they can pick this thing up. Height from the ground is then controlled by the vertical link settings, in tandem with the hydraulics.

//greg//

 

[jnjpream]

Thanks Greg.

The hitch pin diameters I have are all Cat 1. I was assuming that when an implement is fully engaged that the lower links would be parallel to the ground thus removing any pressure from the lift arm hydraulics. But I'm not sure. Which is why I wanted to get a few different measurements.

There has to be some kind of standard, or standard range that implement designers use when calculating how high to build their lower hitch points. If there wasn't at least a target range, they would run into a situation where a taller tractor would pull the implement out of the ground due to the angle of the hitch given that lift hydraulics are single action. Or the situation where the lift hydraulics wears prematurely due to the constant force applied when using the implement. But again, these are assumptions I've made while looking at the system.


Jeff

 

[john_bud]

Huh?

I think your assumptions are faulty. An implement like a plow putts thousands of pounds of pull down force on the 3pt. It's designed to do that so that the tractor has more traction. A box blade, back blade, landscape rake and a tiller will be neutral as thier weight is what holds them down, that's why you always buy those heavy. (tipping the blades down by shortening the top link makes them cut better and DOES give some pull down force.) But other ground engaging implements will give the tractor a down pull thru the 3pt. Even a mower is held up by the 3pt on the front and the wheel at the rear.

The "correct geometry" is adjusted by the top link to make the plane created by the lower and top links normal to the ground. You adjust that depending on how high or low you will be operating, but the 3pt will stay pretty close to your original setting as you lift and lower it.

least ways, thats the way I look at it.

jb

 

[greg_g]

I was assuming ...

Yes, you were. And over-thinking it as well. What's important is to avoid binding. That will hurt components worse than anything else. To avoid binding, don't mess with the geometry. And if you do, make sure your modification is to another accepted standard. That's why I uploaded that simple Cat 1 diagram.

You've probably got a Cat 1N (narrow). So if you want to use regular Cat 1 implements, you have to widen the distance between the lower lift arms - NOT lower them. But the reason there's a Cat 1N to begin with, is the distance between the two rear tires. If you try to widen a Cat 1N, you risk hitting the rear tires with the lift arms. Expensive proposition.

If in fact your SCUT is Cat 1N, you're probably best off leaving it original - and buying the Cat 1N sized implements. Or - buy a bigger tractor.

//greg//

 

[jnjpream]

Yes I was, and I stated that. View your Quote. The hitch I have is a Cat1, not Cat 1N. It will reach the 26 inch wide pins of a Cat1. All I'm going to do is to raise the attachment point of the hitch. All angles stay the same, all distances between hitch points stays the same. The only difference will be that the hitch points where they attach to the implement will be X inches higher. X is the number I'm looking for. There are multiple threads where people have drilled holes in the mounting brackets of implements to add pins lower than the original pin locations. The distance they lower the pins is varied and.. Oh screw it!

All I was asking for was a simple measurement. If your not going to help, no need to reply.

 

[wushaw]

I built a disk and put my lower 3pt pin location at 13" from the ground. I also built a carry all kind of thing to carry a water tank, pins 13" on that one also.

Every other store bought implement I have has their hitch pins higher I guess for a wide variety of tractor heights.

 

[jnjpream]

There ya go, useful information! Thanks wushaw!

The ASABE spec for a draw bar is 15" from the ground for Cat1 and Cat2. Cat3 and Cat4 jump to 19". 13" is pretty close to that, so I'm wondering if the lower link spec for a 3PH is the same as the draw bar spec..? I wish I knew somebody with the S217 spec.

Thanks again wushaw.

 

[greg_g]

wish I knew somebody with the S217 spec.

You do, sorta. But I think you'll be disappointed.

//greg//

 

[JerryK]

My Cat2 is 19", with 16.9X28 rears. The 2240 I have could be procured with many different tire sizes, which would all change the pin height....and Cat1 would be the same....tractor and tire combo dependant.....