Increasing the lift capacity of a FEL

[LD1]

Here is a tidbit of info on bucket curl, i.e. rollback force. When curling, the pressure is simply applied to the rod side of the piston, however when reverse rollback is used to dump or backdrag, on many tractors the pressure is applied to both sides of the piston, thus intentionally limiting the reverse rollback force to rod area x the pressure. This makes for a fastest dump cycle, & limits the force protecting the cylinder from buckling.

Thats what they call a regen circuit.

Some manufactures DO call it a "fast dump".....allthough in real world practice....it actually SLOWS down the dumping when dumping a full load of dirt or stone.

With the weight in the bucket, Gravity can act on the cylinders faster than the tractor can fill the cylinder. Inducing air in the system. Which is why some people have what we refer to as "floppy bucket syndrome" where when they dump a load....then immediately try and back drag to spread said load....the bucket flops around. Thats because the curl cylinders arent rigid and full of oil. Rather they have air because of a non-regen dump.

By using regen...and applying system pressure to both ports, keeps the cylinder full of oil and actually slows the dump.

Some tractors have BOTH settings. The dump position is a 2-position spool...kinda like lowering the loader....then push further beyond a detent and you're in float. Same for regen on some loaders.

It is important to know what you have if you use a diverter valve for a front grapple or snowplow. If you have a regen ONLY valve, performance will less than desired on a grapple, and on a plow with SA cylinders, it wont work at all if using the left-right curl circuit.

I dont think "limiting" the dump force is even a consideration for the MFG's

In most of the rest of the hydraulic world....IE: industrial and other machinery....a regen is indeed used for faster speed. Fast speed/less power. Like regen valves for logsplitters or hydraulic presses. With the ability to shift out of regen for slower speed/more power. But that isnt the intent with loader valves

 

[the old grind]

Thats what they call a regen circuit.

Some manufactures DO call it a "fast dump".....although in real world practice....it actually SLOWS down the dumping when dumping a full load of dirt or stone.

My FELs are the opposite. (all four) With an empty bucket or grapple if I try to tilt down quickly (in regen/position mode) there's barely any movement & I have to back off the detent to speed it up. Goes faster with any kind of load. YMMV

Float isn't much different for me, where speed of the drop also depends on load, but I'm pretty sure only curl has regen. btw, my CUT's are all NH or CNH w/OEM FELs.

 

[LD1]

My FELs are the opposite. (all four) With an empty bucket or grapple if I try to tilt down quickly (in regen/position mode) there's barely any movement & I have to back off the detent to speed it up. Goes faster with any kind of load. YMMV

Float isn't much different for me, where speed of the drop also depends on load, but I'm pretty sure only curl has regen. btw, my CUT's are all NH or CNH w/OEM FELs.

YEa, there is no regen on loader lift. Float is totally a different function.

I was just using that for comparison as what a the movement of the joystick would feel like.

Raise and curl are only one position on the joystick and comes to a hard stop. Lower...it moves further, past a detent and into float. On loader valves that have BOTH regen and normal dump....the lever feels similar for that second position.

If stickers are still present on the tractor....the loader joystick diagram should illustrate that second dump function. I have seen some loader valves were first position is regen and second is normal....and i have see it the other way around.

My L3400 had a two position dump. My MX is a single position Regen only.

 

[sandman2234]

When did regen on a loader come out? This is my first loader and no sign of regen on any of the labels.
David from jax

 

[mike69440]

When did regen on a loader come out? This is my first loader and no sign of regen on any of the labels.
David from jax

Does it dump a lot faster than it curls? If so it most likely is a regen circuit.

 

[sandman2234]

Does it dump a lot faster than it curls? If so it most likely is a regen circuit.

I really haven't paid that much attention to the speed at which it dumps compared to the speed of the curl. However, I can imagine that the dump "should be" slower due to the difference in the size of the cavities where fluid is flowing. (kind of the same discussion as before on strengths of push/pull). Pushing has a larger cavity to fill so should be slower, which would make dumping slower.
One day I will get back to my tractor and figure this out.(won't be in next 2 weeks!)
A good friend has made this discussion a little easier by sending me a scale by which I can actually check the weight of a Toro Workman. I will still have to have time to do this, and it won't be possible to check the previous ones I handled because they are 550 miles away now. The ones I have at home are cab units or have several more options that add significant weight. I may check to see how the Kubota does lifting the open station one.
David from jax

 

[LD1]

When did regen on a loader come out? This is my first loader and no sign of regen on any of the labels.
David from jax

Not sure. I know it has been around for some 20-25 years.

 

[AnotherBueller]

No. Common misconception.
No idea where it started or who came up with breakout force somehow having anything to do with curl, or even the mention of somehow using both functions to "increase" the lift potential.

Nope. Its simply the lift capacity AT GROUND LEVEL.

If it had anything to do with curl at all.....how could we have a spec of breakout AT PIN. Because the PIN they are referencing is the pin in which the bucket curls about....therefore the curl cylinders have no bearing on lift force at that point.

If the bucket heel, be it the FEL or on the back hoe, is in contact with the ground then there is some leverage involved which increases the lift forces. I've cracked a 12" bucket leveraging ageist a tree root once.

 

[AnotherBueller]

I really haven't paid that much attention to the speed at which it dumps compared to the speed of the curl. However, I can imagine that the dump "should be" slower due to the difference in the size of the cavities where fluid is flowing. (kind of the same discussion as before on strengths of push/pull). Pushing has a larger cavity to fill so should be slower, which would make dumping slower.
One day I will get back to my tractor and figure this out.(won't be in next 2 weeks!)
A good friend has made this discussion a little easier by sending me a scale by which I can actually check the weight of a Toro Workman. I will still have to have time to do this, and it won't be possible to check the previous ones I handled because they are 550 miles away now. The ones I have at home are cab units or have several more options that add significant weight. I may check to see how the Kubota does lifting the open station one.
David from jax

Yes, it will dump faster than it curls because the rod takes up volume in the cylinder so there's less fluid to come out of the cylinder, but only if the system has regen, where the valve lets some of the dump side flow into the pressure side.

 

[sandman2234]

I am learning a lot from this post!
Just to let everyone know that I won't be increasing the size of my Kubota loader cylinders. I just purchased another JD2555, this one with a 640 loader (and 4wd). Now if one won't pick it up, I get a someone to grab the other one and between the two, they should be able to pick it up.
David from jax