breakout force

[tman1020]

can someone please clarify for me if i am understanding breakout force correctly. in this example i use a loader. breakout force is total amount of force a the loader will create before the relief valve will relief. i understand this is calculated at different points of measure but what i don't under stand is why it is different from loader capacity. shouldn't this be one in the same? thanks..

 

[RedNeckRacin]

Related but not the same. Loader capacity changes throughout the arc of the arms.

 

[SPYDERLK]

Lift force diminishes steadily with height. Capacity is what can be lifted to full height. Breakout is what is available at ground level.
,,larry

 

[tman1020]

It's often a big difference between the too.

 

[LD1]

Yep. The angle change of the cylinder to boom is often a big difference too.

Its not uncommon to see 2x's more force @ ground level

 

[GreenWannabe]

Breakout force is the combination of the weight of the tractor, the lift capacity of the loader at ground level, and the force exerted on the cutting edge of the bucket generated by curling the dump cylinders, all at the same time. Generally it is a theoretical value, as combining lift and curl simultaneously may not actually allow maximum force on both hydraulic circuits, but the manufacturers use the maximum force generated by both cylinders anyway. Breakout force is the force available to fill the bucket as it is lifted and curled. HTH.

 

[SPYDERLK]

Breakout force is the combination of the weight of the tractor, the lift capacity of the loader at ground level, and the force exerted on the cutting edge of the bucket generated by curling the dump cylinders, all at the same time. Generally it is a theoretical value, as combining lift and curl simultaneously may not actually allow maximum force on both hydraulic circuits, but the manufacturers use the maximum force generated by both cylinders anyway. Breakout force is the force available to fill the bucket as it is lifted and curled. HTH.

Thanks. That seems more complete and makes sense. ... All except the weight of the tractor.
larry

 

[dfkrug]

There are ISO and SAE standards defining breakout force, tho you will have to buy them to
read them. That force occurs at the best leverage the bkt curl function sees, measured
at the tip or root of a bkt tooth. Hoe or FEL.

By feathering the stick, you can apply downward force with the boom cyl at the same time
as with the bkt cyl. I do not recall if that is included in either standard. I don't think
so, however, as my calcs for bkt-only cyl max force seem to be close to factory specs
for breakout.

 

[xtn]

Usually the curl function can provide greater force out at the edge of the bucket than the boom lift function can. They are not additive.

For example, if you're trying to scoop mud, and it's putting 3000 pounds of resistance against your bucket edge... using your curl function to push the edge of the bucket on up and through to complete the scoop will work if your breakout force is more than 3000 pounds, and it won't work if your breakout force is less that 3000 pounds. If your bucket cannot curl through the material being scooped, adding in some boom lift isn't going to help it, generally speaking.

xtn

 

[SPYDERLK]

Usually the curl function can provide greater force out at the edge of the bucket than the boom lift function can. They are not additive.

For example, if you're trying to scoop mud, and it's putting 3000 pounds of resistance against your bucket edge... using your curl function to push the edge of the bucket on up and through to complete the scoop will work if your breakout force is more than 3000 pounds, and it won't work if your breakout force is less that 3000 pounds. If your bucket cannot curl through the material being scooped, adding in some boom lift isn't going to help it, generally speaking.

xtn

Yes. Boom lift is also offset/countered by pushing ... whereas curl; hardly.
larry

 

[dfkrug]

Usually the curl function can provide greater force out at the edge of the bucket
than the boom lift function can. They are not additive.

I meant to say downward force, not lift. Good catch. Edited.

The force vector delivered by the bkt tooth at maximum is downward and to the rear, so
added force at least partially in those directions would increase the total force. What
is not clear is if the breakout force standards include force from ONLY the bkt curl action.

 

[tman1020]

Well this is getting very technical. Spiderlk cave

 

[tman1020]

Well this is getting very technical spider LK gave a fairly simple answer that seem to make quite a bit of sense would that be a good way to sum it up?

 

[the8080]

Breakout force is the force at the cutting edge or teeth of the bucket. It is used to measure digging force. Usually more important in a backhoe or excavator than FEL. This is mostly a function of the "curl" power of the bucket. The lift is just that and is a function of the force in the arms of the loader. Breakout is important for digging and getting the bucket loaded, lift is important for how much the bucket, forks, etc can lift once loaded.