Is "breakout force" the amount a loader will lift?

[SPYDERLK]

I seriously doubt they would change the definition of breakout force with any revision to the specification.
Breakout force is lift cylinders only. It's so much higher because of how the cylinder/boom geometry changes with height.

"5.1.5 Breakout force a腎 pivot pin (Y): Vertical lifting force, in newtons
(pounds), the loader will exert at the bucket pivot pin centerline using the
lift cylinders only, with the bucket horizontal at ground line.

5.1.6 Breakout force (Z): Vertical lifting force, in newtons (pounds), the
loader will exert located 800 mm (31.5 in.) forward of the bucket pivot pin
centerline using the lift cylinders only, with the bucket horizontal at
ground line.

5.1.7 Bucket rollback force at maximum height (VV): Vertical lifting
force, in newtons (pounds), the bucket will exert, located 800 mm (31.5
in.) forward of the bucket pivot pin centerline, using the bucket cylinders
only, with loader at maximum height and bucket horizontal.

5.1.8 Bucket rollback force at 1.5 m (59 in.) lift height (XX): Vertical
lifting force, in newtons (pounds), the bucket will exert located 800 mm
(31.5 in.) forward of the bucket pivot pin centerline using the bucket
cylinders only, with the loader positioned to locate the bucket pivot pin
centerline at 1.5 m (59 in.) above ground line and bucket horizontal.

5.1.9 Bucket rollback force at ground line (ZZ): Vertical lifting force, in
newtons (pounds), the bucket will exert located 800 mm (31.5 in.)
forward of the bucket pivot pin centerline using the bucket cylinders only,
with the loader positioned to locate the bottom of the bucket cutting edge
horizontal at ground line.

In other words, any of the above. I would suspect that a manufacturer is going to go with the highest number that they get from any one of these descriptions. Mostly it is a numbers game that mfg. play with the consumer and there is no way to tell which of the numbers they are using. None of my tractors will perform like my old grey market Yanmar with the Vietnam built FEL. It would lift the rear of the tractor with the FEL when it(the bucket) was hung under a stump, rock etc.

,,,,,,,In other words, the 1st two of the above.

 

[SPYDERLK]

Kinda hard to understand why my FEL won't lift 2 55 gal poly drums of water with 2k+ lbs of 'BOF' (measured 'wherever') and using lift cyls only, not budge 'em the least. (can raise 1 full and one ~1/2 full to several feet)

Perhaps rather than properly define BOF we (and some OMs) are misapplying the term to describe 'rollback force'. (Kleenex, Ping Pong, Bush Hog, Ditch Witch are brand names more broadly applied and commonly accepted as descriptive terms than bathroom tissue, table tennis, brush cutter or trencher.)

Going 'by the book' depends on which book (vs popular terminology), and the numbers aren't being parsed the same by all. I will no longer claim to understand BOF any more than hp actually 'lost' when pulling with HST. :confused3: ... :laughing:

Well, that 2K is probably at pins. How far are the drums ahead of the pins and how much does the attachment weigh? Also I hear that the relief pressure setting is found to be low on many tractors. :confused3:

 

[the old grind]

Larry, center of mass is maybe 18" forward of pins with a level bucket. Something reduces useful lift by ~60% (vs 'BOF') and I doubt that my 5' 1/3 yd bucket weighs more than two hundred lbs, surely not 12 hundred. Seems I can lift ~600 lbs of water in poly drums. (beware the use of 'poly' to describe plastics in general ) Not much to attach to/measure from behind the pins, and not ready to think I have 150% more muscle forward of them.

Confuzzled as to how a 150% greater BOF (than 'lift') could be valuable if I can't use it, or how measuring it anywhere but at the lip makes much sense to me. :duh: (a nod to using it to describe roll back force?) btw, there seems to be no point at which the lift cylinders (and their applied force) are ever perpendicular to the load/fulcrum vector.

Can't see how the ~10% pressure increase I have room for (within typical (safe) 2500psi component/hose specs) would multiply the useable force exerted at pins or anywhere I can harness it. I surely don't seem to be able to 'break out' all that much using lift alone.

Popular use of term & tool usage meets forensic voodoo? I used to 'get lost' for fun. At 65 it's becoming part of my daily routine.

 

[SPYDERLK]

Larry, center of mass is maybe 18" forward of pins with a level bucket. Something reduces useful lift by ~60% (vs 'BOF') and I doubt that my 5' 1/3 yd bucket weighs more than two hundred lbs, surely not 12 hundred. Seems I can lift ~600 lbs of water in poly drums. (beware the use of 'poly' to describe plastics in general ) Not much to attach to/measure from behind the pins, and not ready to think I have 150% more muscle forward of them.

Confuzzled as to how a 150% greater BOF (than 'lift') could be valuable if I can't use it, or how measuring it anywhere but at the lip makes much sense to me. :duh: (a nod to using it to describe roll back force?) btw, there seems to be no point at which the lift cylinders (and their applied force) are ever perpendicular to the load/fulcrum vector.

Can't see how the ~10% pressure increase I have room for (within typical (safe) 2500psi component/hose specs) would multiply the useable force exerted at pins or anywhere I can harness it. I surely don't seem to be able to 'break out' all that much using lift alone.

Popular use of term & tool usage meets forensic voodoo? I used to 'get lost' for fun. At 65 it's becoming part of my daily routine.

You might be surprised. ... I did some measurements using a force gauge and pressure gauge on the 7520 recently. It takes nearly 1Kpsi to bring the bucket off the ground. I couldnt believe it so I did some skeptical investigation - its right. ... To be fair, the SSQC, 6' bucket and Tilt tatch together weigh about 1K# out in front of the pins. -- So, net zero at 900psi. At 3Kpsi the net center bucket lift force is 5100# at 1 foot lift height. This is 26" ahead of the pins.
,,, I expected less.
larry

 

[Sysop]

Basically from my understanding, which really hasn't been explained here yet that I've seen; hydraulics are at their most powerful when fully retracted and weakest at their farthest extension.

Breakout force and max lift specs are mostly useless independently.

Breakout force is the maximum amount of weight that can be supported by the machine. If your loader has 5000# of breakout force and you put 5005# in the loader, between the curl and lift you will take 5000# of weight, but not lift it. Moving around would be akin to dragging a 5# weight across the ground.

You also need the maximum lift spec to make a good choice. Max lift is always spec'd to full height, the weakest scenario for the hydraulics. If max lift is 2500# to 120", you can then figure how much lift is available at various heights you need. If you need to lift 3500# pallets into a truck that sets 48" up, you can figure the above numbers should allow you to lift 3750# to 60" pretty easily.

It also allows you to make comparisons of the hydraulic system component sizing from the manufacturer. When doing the math, you'll learn some loaders will breakout tremendous loads but fall off rather rapidly as you lift, and others will have a weaker breakout compared to their overall lift. As with most things on tractors, you need to study what your uses will be to make a good decision.

 

[bcp]

Basically from my understanding, which really hasn't been explained here yet that I've seen; hydraulics are at their most powerful when fully retracted and weakest at their farthest extension.

I don't believe there is any push or retract force difference, but there is a bending resistance difference, and, due to possible leverage issues, there can be a difference in work done. Compare a dump trailer cylinder to a loader cylinder on weight lifting at different positions.

Bruce

 

[Sysop]

Compare a dump trailer cylinder to a loader cylinder on weight lifting at different positions.

If you're talking the little homeowner style dumps like mine, it is a different geometry altogether, but taking a close examination still doesn't prove or disprove anything.

A dump trailer like mine requires the most forces to initially lift the bed from the frame, and this is done with the ram fully retracted. During this part of the process force is not exerted to lift, but is pushing forward on the bed against the hinges. A combination of the extreme forces exerted by the ram, with the slight angle the ram is mounted at, the pivot allowed by the hinge, as well as a small leaf spring to help it get started; is what creates the upward force to start the lift and takes the greatest amount of hydraulic force of the entire dump process to accomplish. As it lifts the load requirements of the hydraulics are lessened as the weight is transferred to the hinge until enough height is gained the load begins to shift rearward and dump.

 

[SPYDERLK]

I don't believe there is any push or retract force difference, but there is a bending resistance difference, and, due to possible leverage issues, there can be a difference in work done. Compare a dump trailer cylinder to a loader cylinder on weight lifting at different positions.

Bruce

Effective area of piston is less during retract.

 

[SPYDERLK]

Basically from my understanding, which really hasn't been explained here yet that I've seen; hydraulics are at their most powerful when fully retracted and weakest at their farthest extension.

There is no hydraulic difference in the retracted condition, but since it is closer coupled the cyl is not as subject to damage. Loss of force in lift is a result of changing force geometry rather than a loss of hyd force.

 

[the old grind]

... Loss of force in lift is a result of changing force geometry rather than a loss of hyd force.

This^^, ... and it easily skews what often seems obvious from mere observation. Also, gravity doesn't necessarily act consistently on objects moved through arcing vs strictly linear paths in other than the X-Y plane.

Arm position and leverage vary through operation so what, 3(?) options to parse if/when the numbers are ever critical?

- pressure test, 'vector mechanics', and a lot of arithmetic
- what the book says
- actual load testing

Unfortunately, none of these promise to refine/resolve any definition of terms.
At least we agree that 'lift' & 'breakout' forces are different critters, eh ... and in a mere 3 pages.