lift capacity numbers

[rScotty]

Heres the specs I mentioned

OK then, looking at those specs we can tell you a lot about your machine. Turn to the second sheet first, because it only has a couple of pieces of information that we need. and they apply to the 3pt hitch, not the front end loader (FEL). First of all that second sheet tells us that yours is a L2501 gear drive 4wd - which I had missed before. And then we go down to the hydraulic section... By The Way, that hydraulic section only applies to the 3pt hitch, not the FEL. And all we care about in that infor is the pressure - which we see is modest (and deliberately limited) at 2205 psi . And then we go up to the lift at " 24" behind the lift points". The lift points are where the implement is connected, and 24" is about where the center of gravity of the implement will be located if it is a simple short implement like a back blade. For the 3pt hitch only, the manufacturer will normally limit the pressure and the lift capactity of the 3pt hitch so that trying to lift something too heavy won't cause the tractor to do a wheelie. From the spec sheet, it says you can lift about 1389 lbs of back blade. Since your typical 6 or 7 foot wide cat 1 back blade only weighs a few hundred pounds you have lots of additional to spare. And that's good, because something like a box blade is not only heavier but it's center of gravity tends to be farther away from the tractor. So the manufacturer gave you enough force to handle a nice heavy implement back there.

BTW, it is cheap and easy for a manufacturer to make the 3pt hitch very, very powerful - so strong that it could damage the tractor. And It is common for them to build in a pressure limiting valve to deliberately reduce the rear lift to a safe level for that tractor. Looking at that 2205 psi number for the pressure tells me that is what the manufacturer has done. The normal gear drive type hydraulic pump used in these tractors will generate a lot more pressure than that if it is not limited.

After some coffee I'll interpret that first sheet for you. It's all about the Front End Loader and is more important for what you are doing. Hope this all helps.
rScotty

 

[rScotty]

Heres the specs I mentioned

On to that first sheet of specs you posted - it's basically just specs for the Front End Loader. In the US, we use pounds (lbs) as our unit for measuing both the amount of material and the amount of lifting force. The rest of the world uses Kilos for the first and Newtons for the second.....which is technically more correct, but lets stick with what we know. So in those specs, only pay attention to the "lbs" and "lbs force" - for us here, those familiar units tell us what we need to know. And 500mm is about 20".... or roughly the distance from the lower bucket pivot pins to where the center of gravity of the load in the bucket tends to be.

BTW, all distances on the FEL spec sheet will be taken from the lower bucket pivot pins - that is where the bucket bottom connects to the loader arms - and that is typical for any loader spec sheet. I've never seen it any other way. Forces taken "at the pivot pins" are how manufacturers compare their loaders - there's some interesting history about that & has to do with advertising and just who means what....
Anyway, what we care about most are specs that are taken forward of the pivot pins where us tractor users normally carry a load. Kubota here is using 500mm which is 20". That sounds about right. You can lift more if you somehow can get the load closer to the pivot pins - but in reality it's only about 20% more and is difficult to do without swapping the bucket for a pair of forks.

My favorite specs on that sheet are the ones labeled as "ZZ" and as "X". So lets look at those. ZZ tells us how much of a centered load that FEL bucket will lift from the ground, (1806 pounds). Don't forget that part of that 1806 pounds is the weight of the bucket itself. By "centered load" I mean a load that is centered at the center of gravity of the bucket - about the normal place you would carry a load of dirt..which from the spec sheet should be at 500mm or 20" forward of the point where the bucket mounts to the loader arms. That is the pivot pin location.

And X tells us how much she will lift when the bucket is 5 feet in the air (1135 lbs). Just where in the lift cycle that the max lifting force will occur is matter of the geometry of the loader arms, bucket, and cylinders. It makes the most sense to me to have the max lift right off the ground, but I believe I've seen other types lift curves. Sometimes specs are published that show lifting force vs height - with a series of almost parallel curves labeled as: at the pins, at the cg, and at the bucket lip. Those make it easy to visualize.

As was said, it is possible to load a bucket by hand with enough weight that something will break and drop the load - but in practice I've not seen it happening. The safety factors are huge. But as sd455dan points out, it is possible to put a lot more load onto a bucket by putting it in a certain position agains something immoveable and then driving forward. I've not seen it happen, but don't doubt it could for a second. However, it is not a problem you are likely to run into loading your tractor with logs or rocks by hand.

And I agree with everyone - if it will lift it, you are not endangering the tractor. However, you might be endangering yourself if you try to drive off with a loaded bucket held up in the air because the tractor will turn over. Always drive with a loaded bucket held down as low as you can.

I'd say that's a nice little loader. It seems well balanced to the tractor. Does any of this help? Questions?
rScotty

 

[ericm979]

Scotty I agree with everything you said (especially travelling with the loader up high) except I think you're reading the chart backwards.

Lift capacity at 500mm from pins at max lift height: 820 lbs
Lift capacity at 500mm from pins at 1500mm height: 1135 lbs
Lift capacity at 500mm from pins at breakout (0 height): 1806 lbs

Lift capacity reduces with lift height. I think that's typical, due to the geometry of the loader and lift cylinders. Both my tractors have done that. It provides a safety factor in that if you lift a load that's less than the breakout capacity but greater than the max lift load, the loader will stop (by tripping the loader valve relief) at the height where the weight is equal to the capacity of the loader. In practice what happens is that you can lift the load only so high. I've run into that with large logs in the grapple.

If you look at the relationship between the lift cylinders and the loader pivot with the loader down vs up you can see why the loader has more capacity down low- the cylinder has better leverage there.

 

[1930]

On to that first sheet of specs you posted - it's basically just specs for the Front End Loader. In the US, we use pounds (lbs) as our unit for measuing both the amount of material and the amount of lifting force. The rest of the world uses Kilos for the first and Newtons for the second.....which is technically more correct, but lets stick with what we know. So in those specs, only pay attention to the "lbs" and "lbs force" - for us here, those familiar units tell us what we need to know. And 500mm is about 20".... or roughly the distance from the lower bucket pivot pins to where the center of gravity of the load in the bucket tends to be.

BTW, all distances on the FEL spec sheet will be taken from the lower bucket pivot pins - that is where the bucket bottom connects to the loader arms - and that is typical for any loader spec sheet. I've never seen it any other way. Forces taken "at the pivot pins" are how manufacturers compare their loaders - there's some interesting history about that & has to do with advertising and just who means what....
Anyway, what we care about most are specs that are taken forward of the pivot pins where us tractor users normally carry a load. Kubota here is using 500mm which is 20". That sounds about right. You can lift more if you somehow can get the load closer to the pivot pins - but in reality it's only about 20% more and is difficult to do without swapping the bucket for a pair of forks.

My favorite specs on that sheet are the ones labeled as "V" and as "X". So lets look at those. V tells us how much of a centered load that FEL bucket will lift from the ground, (820 pounds). Don't forget that part of that 820 pounds is the weight of the bucket itself. By "centered load" I mean a load that is centered at the center of gravity of the bucket - about the normal place you would carry a load of dirt..which from the spec sheet should be at 500mm or 20" forward of the point where the bucket mounts to the loader arms. That is the pivot pin location.

And X tells us how much she will lift when the bucket is 5 feet in the air (1135 lbs). This loader is pretty nifty in that it will lift more at 5 feet height than it will lift off the ground. That's because of the geometry of the loader and cylinders. Most loaders are built that way, but not all. Yep, that means what you think: Theoretically you could load that bucket by hand with enough stuff that when you lowered it to the ground you couldn't lift it again....

As was said, it is possible to load a bucket by hand with enough weight that something will break and drop the load - but in practice I've not seen it happening. The safety factors are huge. But as sd455dan points out, it is possible to put a lot more load onto a bucket by putting it in a certain position agains something immoveable and then driving forward. I've not seen it happen, but don't doubt it could for a second. However, it is not a problem you are likely to run into loading your tractor with logs or rocks by hand.

And I agree with everyone - if it will lift it, you are not endangering the tractor. However, you might be endangering yourself if you try to drive off with a loaded bucket held up in the air because the tractor will turn over. Always drive with a loaded bucket held down as low as you can.

I'd say that's a nice little loader. It seems well balanced to the tractor. Does any of this help? Questions?
rScotty

Very well put and easy to understand. Assuming the poster below you is correct it in no way de-values your response. Putting the entire text together has given me pretty much the info I was seeking and again more food for thought.

Thank-you

 

[MaineGuy1]

Very well put and easy to understand. Assuming the poster below you is correct it in no way de-values your response. Putting the entire text together has given me pretty much the info I was seeking and again more food for thought.

Thank-you

I wouldn't assume just because your tractor can lift it, it can handle it. That is a dangerous assumption IMO.

 

[rScotty]

Scotty I agree with everything you said (especially travelling with the loader up high) except I think you're reading the chart backwards.

Lift capacity at 500mm from pins at max lift height: 820 lbs
Lift capacity at 500mm from pins at 1500mm height: 1135 lbs
Lift capacity at 500mm from pins at breakout (0 height): 1806 lbs

Lift capacity reduces with lift height. I think that's typical, due to the geometry of the loader and lift cylinders. Both my tractors have done that. It provides a safety factor in that if you lift a load that's less than the breakout capacity but greater than the max lift load, the loader will stop (by tripping the loader valve relief) at the height where the weight is equal to the capacity of the loader. In practice what happens is that you can lift the load only so high. I've run into that with large logs in the grapple.

If you look at the relationship between the lift cylinders and the loader pivot with the loader down vs up you can see why the loader has more capacity down low- the cylinder has better leverage there.

Yes! Absolutely... Eric, thanks for the correction. I did the unthinkable & misread the specs I've edited the original and hopefully got the numbers right this time.
rScotty