Bucket Breakout Force

[Gem99ultra]

It's embarrassing to be so ignorant regarding terms that are apparently everyday conversation among so many knowledgeable tractor owners/operators. But, I'd rather be embarrassed than to remain ignorant. So, here's my two questions:

a) What does the term "bucket breakout force" means please.

b) I'm also trying to understand the amount of weight the FEL on a B2650 will handle, assuming I've added plenty of counterweight. That info never seems to be published. Is there a rule of thumb, or just how can I predetermine, short of damaging the tractor?

Many thanks for the education.

 

[bridge4]

It's embarrassing to be so ignorant regarding terms that are apparently everyday conversation among so many knowledgeable tractor owners/operators. But, I'd rather be embarrassed than to remain ignorant. So, here's my two questions:

a) What does the term "bucket breakout force" means please.

b) I'm also trying to understand the amount of weight the FEL on a B2650 will handle, assuming I've added plenty of counterweight. That info never seems to be published. Is there a rule of thumb, or just how can I predetermine, short of damaging the tractor?

Many thanks for the education.

I remember being told "If you have a question, someone else probably has the same one". I'd be happy to hear more information on this too, since tractor companies tout this spec a lot.

 

[diesel85]

This is what I've felt is the correct answer from using machinery for a good part of my life: Breakout force is the combination of the lift cylinders and the curl cylinders both operated at the same time at ground level to break out of the pile. Sometimes measured at the bucket lip, sometimes measured at the pins

 

[RjCorazza]

Breakout force is what the bucket roll back function is capable of, for example when you chain a fence post to the bucket and roll the bucket back to exert force of the post.

The other specifications have historically not been very standardized. Some give full height ratings at the loader bucket PINS, some at 500mm forward of the pins. I have also seen more real world estimates of specified bucket sizes lifting various materials in a struck or heaped bucket. All material will have different densities and weights, so it's not very precise.

I have never been too concerned about exceeding my loader's capacity. It will complain when you ask too much of it. I will say that I generally don't push the limits when doing loader work.

 

[RjCorazza]

I never considered breakout force as combining the lift and curl cylinders. I suspect if manufactures could advertise a higher number using both, that they would.
Anyway, here are the hard numbers for the B2650 (don't know what bucket type of there are options :

 

[moship]

Can't speak for the FEL manuals for the B2650, but other FEL operator manuals included lift curves that might provide the information your looking for.

Perhaps someone with a B2650 FEL operator manual could snap a picture of the pages and post for you. (Assuming the curves are still published)

Example from my Grand L series tractor shown below for reference.

 

[diesel85]

RJ, the reason I mention this is from lots of time behind machines with loaders. Lift capacity is from the two outer (side) cylinders, and breakout if from all cylinders. I notice if I dive into a load, and not use the bucket cylinder, the machine has a tougher time picking the load up from the pile, versus using all available cylinders.

 

[RjCorazza]

RJ, the reason I mention this is from lots of time behind machines with loaders. Lift capacity is from the two outer (side) cylinders, and breakout if from all cylinders. I notice if I dive into a load, and not use the bucket cylinder, the machine has a tougher time picking the load up from the pile, versus using all available cylinders.

It makes perfect sense. It just never occurred to me. I did research my tractor's specs, and Kubota does in fact list a breakout force that is higher than the listed "roll back force".
Learn something every day!

 

[Dave M7040]

This is what I've felt is the correct answer from using machinery for a good part of my life: Breakout force is the combination of the lift cylinders and the curl cylinders both operated at the same time at ground level to break out of the pile. Sometimes measured at the bucket lip, sometimes measured at the pins

With an open center system, which is what most Kubota farm tractors have, you cannot develop max pressure in both the bucket and lift arm cylinders at the same time.

Dave M7040

 

[diesel85]

Well, it may not be, but I also have a feeling physics has something to do with roll back and lift at the same time to get a nice chunk of feed, dirt or a stump out.

All I'm giving is from an operators perspective. Whether or not it's hydraulic forces in action, might well not be. Who knows. LOL

 

[Fallon]

With an open center system, which is what most Kubota farm tractors have, you cannot develop max pressure in both the bucket and lift arm cylinders at the same time.

Dave M7040

I'm actually not clear on that. For any plumbing downstream of the loader valve (3rd function, rear remotes, 3pt, etc) that is 100% true. But internally the loader valve is plumbed in series & parallel. That gives you the option to lift & curl at the same time. I ASSUME that also means you can get full pressure to both circuits, especially when they stall out.

As for the other comment from somebody else about not worrying as about lift capacity. That depends. My L3200 could lift the rear end with decent ballast & was still squirly with heavy ballast. My L4060 is rock solid at max capacity with minimal ballast & probably no ballast if I ever tried. The lighter the machine the more likely you are to be able to get into problems. Make sure you know if you can get into problems before adopting that stance. As the front axle is on a pivot, as soon as the rear comes off the ground your machine will roll sideways. It's not just picking the back end up, you are very likely to roll the machine if you do.

 

[100 td]

But internally the loader valve is plumbed in series & parallel. That gives you the option to lift & curl at the same time. I ASSUME that also means you can get full pressure to both circuits, especially when they stall out.

It depends on the PB bypass circuit of each individual valve block, and there are many circuit variations, and whether the spool allows PB flow-on when feathered.

 

[Gem99ultra]

Excellent info, although much of it is over my simple mind. I do, however, do understand now the 'bucket breakout force' definition.

The FEL lifting specs, in summary are obviously totally dependent on multiple variables, such as height, distance from the pins, etc.. That explains to me why I can't pick up very large felled trees. I'm not wanting to max out the B2650 capability for sure, nor to venture into unsafe conditions. More experience with this tractor is clearly obvious.

I just now got all of the manuals, i.e. Shop, Parts, and Users. Lots of browsing the pages is in order.

Many thanks to the contributors. Your knowledge and experience is impressive, and appreciated.