Tractor Sizing How Much Can A Sub Compact Tractor lift?

[gladehound]

Break out at the pin is different than lift capacity at the pin. Lift capacity uses only the lift cylinders. Break out force uses both the lift and curl cylinders. Obviously, you can't always use the curl function to lift a heavier object, so it gets listed as a separate spec...it's supposed to simulate digging a bucket of dirt out of a pile (or similar).

He's asking what the ground level lift capacity is at the pin, and they don't publish it that way....unfortunately.

I have read others describe breakout force this way and would like to know the origin of this definition as I do not think it is correct. I believe the origin is that a bunch of TBN'rs talked about it until they reached an incorrect consensus that it is some combination of lift and curl. I believe the way breakout force is used for CUTS, it is simply the vertical component of lift from the loader arms when at ground level. I believe this is true because it is the only definition that makes sense given that this force is given at the pins.

If it is combination of lift and curl, that would suggest that you can somehow increase lift force at the pins by curling. But you can't. You can only increase lift force at the pins by dumping and I know lift and dump together is not the definition of breakout at the pins. Because if it were that breakout number would have to be much, much higher than it is. On my tractor, dump and lift together and you can get over 8,000 pounds of vertical force at the pins. But the listed breakout is ~3800.

Lift capacity typically describes the vertical component of the lift arm force at full height unless a different height is specified.

Roll back force is the curl force given at a certain distance from the pins.

Now when looking at specs for construction equipment it is all different. Breakout for construction equipment typically refers to bucket rollback force which is typically stronger than lift.

I believe "breakout force" morphed for CUTS to make it sound like more than it is. If they gave actual breakout forces at the bucket edge, the numbers are typically much less impressive. Most small CUTS have less curl force at the bucket edge than loader lift force at the pins. So the numbers just wouldn't look good.

 

[GManBart]

I have read others describe breakout force this way and would like to know the origin of this definition as I do not think it is correct. I believe the origin is that a bunch of TBN'rs talked about it until they reached an incorrect consensus that it is some combination of lift and curl. I believe the way breakout force is used for CUTS, it is simply the vertical component of lift from the loader arms when at ground level. I believe this is true because it is the only definition that makes sense given that this force is given at the pins.

If it is combination of lift and curl, that would suggest that you can somehow increase lift force at the pins by curling. But you can't. You can only increase lift force at the pins by dumping and I know lift and dump together is not the definition of breakout at the pins. Because if it were that breakout number would have to be much, much higher than it is. On my tractor, dump and lift together and you can get over 8,000 pounds of vertical force at the pins. But the listed breakout is ~3800.

Lift capacity typically describes the vertical component of the lift arm force at full height unless a different height is specified.

Roll back force is the curl force given at a certain distance from the pins.

Now when looking at specs for construction equipment it is all different. Breakout for construction equipment typically refers to bucket rollback force which is typically stronger than lift.

I believe "breakout force" morphed for CUTS to make it sound like more than it is. If they gave actual breakout forces at the bucket edge, the numbers are typically much less impressive. Most small CUTS have less curl force at the bucket edge than loader lift force at the pins. So the numbers just wouldn't look good.

Obviously, this is a separate topic from this thread, but I can't begin to imagine where you came up with this concept. The loader on a CUT works the same way as a loader on a wheel loader does, and the SAE has a published procedure for testing...and it doesn't match your description. They don't limit it to only the curl/rollback function.

http://www.tractorbynet.com/forums/...s-breakout-force-post1563597.html#post1563597

Lift capacity at ground level is exactly that...lift capacity at ground level. Most companies don't provide that figure, but when they do, they also provide a breakout force figure, and it's not the same.

Breakout force means just what it says...how much power the loader has to break out a chunk of dirt from the pile, and to do that, you use both lift and curl. Try running your bucket into a pile of dirt with the bottom exactly level with the ground, and see how well it works...just pull back on the loader control, and leave the bucket level....not going to work well at all. You need to use the bucket curl's additional power to actually break it free from the pile.

 

[LD1]

Well I don't know what breakout means, but fwiw, the breakout on my loader is listed at 2442#. Ironically, according to the lift chart, the loader lift at ground level is 1200kg...pretty much the same thing.

I will also say my loader has a lot more curl at the bucket edge than lift. There are many times I cannot lift a log on the forks, but am able to curl to get it just off the ground to saw up. Same with digging stumps.

I have a gauge on my lift circuit. I can lift for all its worth which is 2650psi. Holding there, applying curl I can watch the gauge peg up to about 3500. So that means my loader cylinders would need to have 3500 psi going to them to match my curl power.

And to further complicate matters, curl power isn't a static fixed number either. Just like loader lift, it matters where in the range of motion it is. There is a fancy graph for that too in my manual. It has most power around mid range, and is weakest near either full dump or full curl.

But one thing is certain, there is no simple answer or simple way to rate what a loader can lift. The geometry of the motions are so dynamic as is just where the load is placed in relation to the pins. That I hope we can all agree on. Seeing what you can and cannot lift is all well and fine, but is really not that usefull in the real world with all the changing variables

 

[LD1]

Well I don't know what breakout means, but fwiw, the breakout on my loader is listed at 2442#. Ironically, according to the lift chart, the loader lift at ground level is 1200kg...pretty much the same thing.

I will also say my loader has a lot more curl at the bucket edge than lift. There are many times I cannot lift a log on the forks, but am able to curl to get it just off the ground to saw up. Same with digging stumps.

I have a gauge on my lift circuit. I can lift for all its worth which is 2650psi. Holding there, applying curl I can watch the gauge peg up to about 3500. So that means my loader cylinders would need to have 3500 psi going to them to match my curl power.

And to further complicate matters, curl power isn't a static fixed number either. Just like loader lift, it matters where in the range of motion it is. There is a fancy graph for that too in my manual. It has most power around mid range, and is weakest near either full dump or full curl.

But one thing is certain, there is no simple answer or simple way to rate what a loader can lift. The geometry of the motions are so dynamic as is just where the load is placed in relation to the pins. That I hope we can all agree on. Seeing what you can and cannot lift is all well and fine, but is really not that usefull in the real world with all the changing variables

 

[4570Man]

My loader has more curl force than lift force. The curl cylinders are the same size as the lift cylinders, but have less leverage working against them, but the curl cylinders are working with a retraction stroke which is weaker than a push stroke. A real loader is designed so that they can curl up using the push stroke of the cylinder.

 

[LD1]

I would say that a "real loader" uses the cylinder extending for curl.

It's all in how its designed and the size of the cylinders. Both designs can be made appropriate to the machine.

 

[gladehound]

Obviously, this is a separate topic from this thread, but I can't begin to imagine where you came up with this concept. The loader on a CUT works the same way as a loader on a wheel loader does, and the SAE has a published procedure for testing...and it doesn't match your description. They don't limit it to only the curl/rollback function.

http://www.tractorbynet.com/forums/...s-breakout-force-post1563597.html#post1563597

This is what the link went to and one of the methods aligns to my description

"SAE J732 is written for larger wheel and track loaders, but should also apply to skid steers and compact track loaders. Breakout force is one of the specifications defined, and here is how it is measured;

1. Loader on hard surface, transmission in neutral
2. All brakes released
3. Unit at standard operating weight, rear of loader not tied down
4. Bottom of cutting edge parallel to ground, no more than .75" above the ground
5. If tilt circuit is used, bucket hinge pin must be specified as pivot point, and lift arms should be blocked under bucked hinge pin to minimize linkage movement.
6. If lift circuit is used, pivot point should be specified as lift arm hinge pin, and front axle should be blocked to minimize tire deflection.
7. If both circuits are used, the dominating pivot point must be specified.
8. If the circuit causes the rear of the machine to leave the ground, the force required to lift the rear of the machine is the breakout force.

This is all listed in the Caterpillar Performance Handbook in the wheel loaders section. In the skid steer section, both lift and tilt breakout forces are listed separately. SCUT, CUT and even UT's often don't list which break out is published and some even fail to follow the specs exactly -- resulting in what I call "marketing numbers" that have little to do with what the machine can do. "

Lift capacity at ground level is exactly that...lift capacity at ground level. Most companies don't provide that figure, but when they do, they also provide a breakout force figure, and it's not the same.

Breakout force means just what it says...how much power the loader has to break out a chunk of dirt from the pile, and to do that, you use both lift and curl. Try running your bucket into a pile of dirt with the bottom exactly level with the ground, and see how well it works...just pull back on the loader control, and leave the bucket level....not going to work well at all. You need to use the bucket curl's additional power to actually break it free from the pile.

#6 above is what most CUT manufacturers are publishing but they publish breakout "at the pins" that is the bucket pins. When any of these methods is used, some fixed distance from the hinge point must be specified otherwise the number is meaningless. CUT manufacturers typically specify the pins, meaning the bucket attachment pins. They could also specify bucket lip on standard bucket, 500mm out from pins, 800 mm out from pins etc.

By specifying the pins, they eliminate the curl cylinders from the test entirely. It is only the lift cylinders. It is impossible for it to include the curl cylinders because of where the force is measured - "at the pins".

This is why LD-1's chart shows the same numbers for ground level lift and "breakout at the pins". Because they are the same! As he said his curl or "roll back" force is much higher.

Now "Roll back" force always means the same thing. The force that you can curl your bucket with at a specified point beyond the hinge pin. However, roll back can mean "breakout" also if method #5 is used. But I have not seen it published this way for modern CUTs. When this method is used, or a combination of lift and curl is used, a distance from the pins (500mm, 800mm, standard bucket lip etc.) will be given to describe it and not "the pins" because in this case, the pins are the hinge point so the force cannot be at the pins.

If lift and curl cylinders are used however, one will dominate. They are in no way additive. Anyone who adds them is incorrectly inflating the figure.

Clear as mud?

 

[gladehound]

Lift capacity at ground level is exactly that...lift capacity at ground level. Most companies don't provide that figure, but when they do, they also provide a breakout force figure, and it's not the same.

.

Yes, lift capacity at ground level is exactly that. Agreed. This figure is listed in CUT brochures as "breakout at the pins" using method #6 of the standard. When companies provide both lift capacity at ground level and breakout force. They are not using method #6 of the standard for breakout force. They are either using method #5 or #7. As such, in these cases it will never say "breakout at the pins". In these cases "breakout" will always be given at some point beyond the pins.

 

[LD1]

Yes, lift capacity at ground level is exactly that. Agreed. This figure is listed in CUT brochures as "breakout at the pins" using method #6 of the standard. When companies provide both lift capacity at ground level and breakout force. They are not using method #6 of the standard for breakout force. They are either using method #5 or #7. As such, in these cases it will never say "breakout at the pins". In these cases "breakout" will always be given at some point beyond the pins.

I have actually never seen a MFG publish a lift at ground level number, other than the chart in my manual.

The 2 common ones I see are
1. Lift to max height
2. Breakout force

2 others sometimes seen are
1. Rollback force
2. Lift capacity to 1.5M

I have to assume that most times breakout force is talking about lift at ground level.

Kubota calls it "boom breakout force (pivot pins)" So I have to assume that is NOT curl, but lift force only, at ground level
Kioti KL401 loader calls it breakout force at pivot pin. its about 1000# more than lift to max height.
Mahindra also calls it breakout force at the pivot pins
Deere measures 4 things
Lift capacity to max height, both at pins and 500mm forward
Lift capacity to 1.5M both at pins and 500mm forward
Boom breakout force, both at pins and 500mm forward
Bucket rollback force

Based on the details of the wording, I'd say at least with those 4 MFG's the breakout = boom lift at ground level. Kubota, kioti, and mahindra dont disclose curl power. But kubota does have it in the manual

 

[LD1]

Have no idea why every single post I have made lately doubles. IF I click "leave this page"...double post. IF I click "stay on this page"...double post.

Eh...good way to boost the post count I guess.

 

[k0ua]

Have no idea why every single post I have made lately doubles. IF I click "leave this page"...double post. IF I click "stay on this page"...double post.

Eh...good way to boost the post count I guess.

The double post thing seems to have returned with a vengence in the last few days. I go back and delete one of the posts as soon as it happens. press edit post, then press the delete button , delete message, delete and it goes away.

 

[gladehound]

Kubota, kioti, and mahindra dont disclose curl power. But kubota does have it in the manual

I was surprised to see you mention that Kioti doesn't list curl power. I checked the Kioti web site and I don't see roll back listed for my loader but it used to be there! It also used to be there for the loaders for the DK45S and the DK55 for sure and probably for the larger tractors as well. I don't recall ever seeing it for the CK series.

I have an old brochure here for my KL402 loader and bucket rollback is listed as 2,990 pounds @ 19.7 inches (500mm).

Ah - just found an old brochure for the DK45S and DK 55

DK45S bucket rollback force at ground line 3,555 pounds (distance looks to be 25.2" but a little unclear")
DK55 bucket rollback force at ground line 4,580 pounds (distance looks to be 25.2" but a little unclear)

 

[LD1]

I could have swore it used to be there on kubotas site as well, but could have been mistaken.

While having alot of curl power is nice, I dont think it is as important of a spec as lift, and often not even mentioned when comparing.

And it es even more dynamic than simple loader lift, that gradually falls off as it is raised. If you drew a graph with force for the Y axis and 0-whatever degrees is the max range of motion for curl being the x axis, that chart would be an arc. Starting small at full dump then increasing til about mid range (usually a little below flat-bottom at ground level), then it will fall back off nearing full curl.

And to even further muddy the waters....

Curl power at bucket edge is usually always stronger than lift. How far in front of the bucket the load is placed for either curl or lift is a straight line.

Curl power starts off greater but falls off faster.

IE: Just throwing numbers out, if you can curl 3k at bucket edge and lift 2k at bucket edge.....
At 24" father out (pallet center), it may be something like 2k curl (33% lost) and 1500# lift (25% lost)
Out 4', it may be 1k all around. Beyond that, lift is stronger.

This happened when I was setting trusses at my old place. 15' boom on the bucket. Couldnt curl back very far at all. Trusses were ~150#. Had to have someone "help" it out. But had no issues at all lifting.

 

[davesl708]

I would argue that a SCUT is not an overgrown garden tractor because it doesn't necessarily have more ground clearance. In fact, compared to the garden tractors I've used, modern SCUTs tend to have much less ground clearance. As such, their design seems to lend them to lawn use more than garden use.

The article also states that a SCUT is similar in dimensions to a garden tractor. Therefore, it is not overgrown grown compared to a garden tractor. Perhaps it would be better to label it an over featured garden tractor. But then there is the ground clearance issue.

Given the design and primary use of a SCUT, it seems to be the top end category of premium lawn tractors. As a premium lawn tractor it has many capabilities that lesser lawn tractors don't have (cat 1 3pt. loader / backhoe availability). CUTs are typically not optimized for yard mowing as a primary task. However, there are some exceptions.

The only reason that I really am not a SCUT fan, is that they seem to be priced on the high side compared to larger tractors. So I struggle with the value equation. But for those who want the versatility and either need the small size to access work areas or have limited space to store equipment I can see how they make a ton of sense.

Well. My JD was 467lbs had a 22hp gas engine and very little ground clearance. It could mow and pull my 25 gal. tank sprayer.

My BX is 1300lbs has 22hp diesel more ground clearance and can operate a FEL, 60" MMM, 4ft tiller, can pull a plow, harrow, pull the sprayer and rear blade. Has cleared over 100 trees and brush <2" and moved dozens of cords of wood.
Cleared 200' of drive of over 10" of snow.

Definitely a different class than the garden tractor I had.

 

[jenkinsph]

I always thought that the break out force assumes curling the bucket where the rear of the bucket on the ground provides a fulcrum point. How much force is applied to the bucket lip would vary with the length of the bucket used. Same is true for a backhoe bucket rolling against itself. The lever length is much shorter and allows you to "pry up" the dirt or rock breaking it free.

I don't have a clue what the manufacturers are using to determine this so I keep reading and watching this thread for enlightenment. At least this thread is good for something.

 

[gladehound]

Well. My JD was 467lbs had a 22hp gas engine and very little ground clearance. It could mow and pull my 25 gal. tank sprayer.

My BX is 1300lbs has 22hp diesel more ground clearance and can operate a FEL, 60" MMM, 4ft tiller, can pull a plow, harrow, pull the sprayer and rear blade. Has cleared over 100 trees and brush <2" and moved dozens of cords of wood.
Cleared 200' of drive of over 10" of snow.

Definitely a different class than the garden tractor I had.

Completely agree that SCUTs are in a very different class than modern Garden tractors. And not trying to put SCUTs down at all. They are very capable small tractors.

The garden tractor / SCUT comparison gets muddy when comparing to garden tractors from a few decades ago that were as heavy as a modern SCUT but lacked some of the features, capabilities. Some of those old Bolens garden tractors were beasts! You have to understand that making this comparison is in no way putting down the SCUT. A wide range of garden tractors have been sold over the years to it depends on what pops into your mind when someone says "garden tractor".

 

[jenkinsph]

Well. My JD was 467lbs had a 22hp gas engine and very little ground clearance. It could mow and pull my 25 gal. tank sprayer.

My BX is 1300lbs has 22hp diesel more ground clearance and can operate a FEL, 60" MMM, 4ft tiller, can pull a plow, harrow, pull the sprayer and rear blade. Has cleared over 100 trees and brush <2" and moved dozens of cords of wood.
Cleared 200' of drive of over 10" of snow.

Definitely a different class than the garden tractor I had.

What model Deere are you referencing? At 467 lbs. this sounds like a lawn tractor not a garden tractor. My x749 is 1200 lbs. plus, so close to the weight of the bx. FWIW I think the BX line are great machines, so not knocking them in any way.

 

[gladehound]

I always thought that the break out force assumes curling the bucket where the rear of the bucket on the ground provides a fulcrum point. How much force is applied to the bucket lip would vary with the length of the bucket used. Same is true for a backhoe bucket rolling against itself. The lever length is much shorter and allows you to "pry up" the dirt or rock breaking it free.

I don't have a clue what the manufacturers are using to determine this so I keep reading and watching this thread for enlightenment. At least this thread is good for something.

And I think you are right as what you describe is method #5 of the published standard. But manufactures have 3 different methods to choose from as listed by the published standard. The method you describe seems to be more commonly used for construction equipment whereas method #6 seems more common for CUTs.

From SAE J732 describing breakout force:

1. Loader on hard surface, transmission in neutral
2. All brakes released
3. Unit at standard operating weight, rear of loader not tied down
4. Bottom of cutting edge parallel to ground, no more than .75" above the ground
5. If tilt circuit is used, bucket hinge pin must be specified as pivot point, and lift arms should be blocked under bucked hinge pin to minimize linkage movement.
6. If lift circuit is used, pivot point should be specified as lift arm hinge pin, and front axle should be blocked to minimize tire deflection.
7. If both circuits are used, the dominating pivot point must be specified.
8. If the circuit causes the rear of the machine to leave the ground, the force required to lift the rear of the machine is the breakout force.

 

[gladehound]

Looking at #8 makes me wonder if my ~3800 is limited by the capability of the loader or by the weight of the tractor. I've lifted the rear with filled tires, cage and blade on the back!

 

[gladehound]

I could have swore it used to be there on kubotas site as well, but could have been mistaken.

While having alot of curl power is nice, I dont think it is as important of a spec as lift, and often not even mentioned when comparing.

And it es even more dynamic than simple loader lift, that gradually falls off as it is raised. If you drew a graph with force for the Y axis and 0-whatever degrees is the max range of motion for curl being the x axis, that chart would be an arc. Starting small at full dump then increasing til about mid range (usually a little below flat-bottom at ground level), then it will fall back off nearing full curl.

And to even further muddy the waters....

Curl power at bucket edge is usually always stronger than lift. How far in front of the bucket the load is placed for either curl or lift is a straight line.

Curl power starts off greater but falls off faster.

IE: Just throwing numbers out, if you can curl 3k at bucket edge and lift 2k at bucket edge.....
At 24" father out (pallet center), it may be something like 2k curl (33% lost) and 1500# lift (25% lost)
Out 4', it may be 1k all around. Beyond that, lift is stronger.

This happened when I was setting trusses at my old place. 15' boom on the bucket. Couldnt curl back very far at all. Trusses were ~150#. Had to have someone "help" it out. But had no issues at all lifting.

A lot of great points are made in the post above. And this explains why you have to be careful using buckets designed for skid steers. A person may have more curl than lift with the short bucket that came from their CUT manufacturer. Slap a 42" deep skid steer bucket on there and suddenly that curl feels weak.

All this discussion makes me want to calculate all these forces for my tractor based on cylinder surface area, lever lengths, vector forces, and relief pressure... But that sounds like a lot of work.