3-Point Hitch Boom pole lift expectations

[LD1]

Hmmm ... I guess, that would be so. I think, if it had weighed 450 pounds, as the seller suggested it might, I would have been OK. :laughing:

I seem to be having a few problems, regarding this box blade and the Boom pole, ... Today, I was in the barn, putting that same Boom pole on the tractor. I raised it up to attach the top link and heard a crash. Looked around to see what had happened. When I picked up the boom, it caught on the back blade, which flipped over backwards and knocked a window out. S..t happens!

So, let me get this straight.....

You bought what the seller thought was a 450lb blade....

.....and it turns out that it is a 1000lb blade.....

.....and your tractor wouldnt lift it with a boom pole....

.....but this blade works JUST fine behind the small tractor that couldnt lift it w/ the pole:confused2:

So I have to ask, what tractor do you have??? And what is the model of the box blade??? Because a 1000lb blade is CATII territory, and a catII tractor shouldnt have had any problems with the boom pole.

 

[Verticaltrx]

So, let me get this straight.....

You bought what the seller thought was a 450lb blade....

.....and it turns out that it is a 1000lb blade.....

.....and your tractor wouldnt lift it with a boom pole....

.....but this blade works JUST fine behind the small tractor that couldnt lift it w/ the pole:confused2:

So I have to ask, what tractor do you have??? And what is the model of the box blade??? Because a 1000lb blade is CATII territory, and a catII tractor shouldnt have had any problems with the boom pole.

What a tractor can lift on the end of a 7-8' boom pole is much less than the tractor can lift as far as regular implements go. I think he has a Ford NAA which is rated at 1000lbs lift capacity at 24". So it might be able to use the box blade, but probably not at full capacity. I also have a Ford NAA and I know for a fact that exactly 500lbs is what it can lift on the end of my boom. I had a 5x5' sheet of 1/2" plate which works out to almost exactly 500lbs. Lifted it off the trailer (barely), and it was all it could do to lift it, 3pt shuttering, hydraulic pump chattering, and front tires barely on the ground. Got the job done though. :thumbsup:

 

[tmajor]

So I have to ask, what tractor do you have??? And what is the model of the box blade??? Because a 1000lb blade is CATII territory, and a catII tractor shouldnt have had any problems with the boom pole.

Pretty much as Verticaltrx posted above.

I do have an NAA, which is CAT 1. As it turns out, this box blade is probably a Gannon Industrial, which can be CAT 1 or CAT 2. Their specs. for the current model indicate 1,000 + pounds, but it has a hydraulic cylinder for the scarifiers.

The Ford NAA lifts the box fine, when mounted. It will even lift it with the boom, when it is perpendicular to the tractor, but in the case, where it was a problem, it was parallel with the tractor, as it was in the P/U bed and the tractor was behind. So, a good portion of the weight ??, was 8 feet behind the tractor.

 

[LD1]

I understand that what it can lift is less.

That is NOT what I was questioning.

My point was simply that a 1000lb box blade is designed to move ALOT of dirt. And a tractor that struggles to lift it on a boom pole isnt big enough (heavy) to use that blade to its full potential.

Again, I am not questioning its ability to lift it when mounted on the 3PH. Just that IF you dont weigh enough to lift it with the boom, you probabally dont have enough weight to create sufficent traction to use that blade agressivly at all.

 

[tmajor]

Life will go on ...

 

[Soundguy]

a Heavy box blad is still a nice thing though. most people complain about them being too light.

soudnguy

 

[Fast Eddie]

However, they do not - so it isnt a simple lever. The 3ph is a parallelogram linkage which, if perfect, would lift the boompole straight up without pivot/rotation. Such a condition would quarantee a very hi % of the lift at the eyes was available at any point on the boompole. Since it is not perfect you lose about 30% behind the eyes.
larry

At first I didn't understand this.but now it makes sense. I went to my shop and took some measurements on the boom pole & I came up with the diagram below. To figure the lift for my JD 790, I looked in the manual and found that the 3 point exerts a force of 815 lbs at a point 24" behind the pivot point.

A calculation not shown is if the load is at the end of the pole, the lift force is 244 lbs. You can get this number by setting x = 0 in the first equation.

The first calculation shows that if the load is moved to 30" from the end of the pole, the lift force increases to 391 lbs.

The second calculation shows where to hang the load if you know how much you want to pick up. For example if you want to pick up 350 lbs, the chain should be 24" from the end of the pole.

None of this takes into account the load capacity of the 3 point pivot points (not sure what to call them), or the load being so heavy it lifts the front end of the tractor.

Sorry if this seems convoluted but it's the only way it makes sense to me. My wife is always telling me that I make things too complicated. But I hope that this is useful to someone.

Fast Eddie

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