Hydraulic Cylinder ends ?

[pokerboy57]

I was thinking about replacing the cylinders on my FEL to try and add some extra lifting capacity. Are the connecting ends of a hydraulic cylinder changeable / customizable ? Seems that this is going to have to be done for the replacement cylinders to fit the FEL ? I was going to go to a commercial hydraulic shop here in Orlando and see what ideas they have. I just wanted to know your opinion before I start down this road ?

 

[LD1]

WhAt are you wanting to do that you need extra lift? IIRC, the 300 loader specs pretty stout given the weight of the machine? Have you had your pressure tested? I would start there if you feel it is weak.

As far as cylinder ends, they can be had in about any configuration. But keep in mind, the loader strength and front axle is designed around the cylinders they use. There is a reason they idint go bigger. And also, a larger cylinder will be slower too.

 

[texasjohn]

What LD said +1

 

[J_J]

Actually, you can do just about anything with a welder, hyd, and well placed thoughts.

2 in cyl 1 in shaft at 2500 psi = 7854 lbs

3 in cyl 1.2 in shaft at 2500 psi = 17,672 lbs

You don't want your cyl to contact the frame except at the ends.

Yes, a larger cyl will increase the force, but may increase your tipping potential. However that can be resolved with rear weight.

Like someone said, check your relive valve specs.

A decrease of 200 psi will cause you to lose about 608 lbs. of lifting weight.

 

[LD1]

If I remember right, assuming he is talking about his 3320, I was thinking the lift capacity was somewheres around 2000# at the pins to a height of 59". Thats an awfully lot for a 2900# tractor to be lifting.

And a 200psi decrease might not quite be 608# of lost capacity. Not sure what bore size cylinder is on the 300 loader. But 608# might be what is lost in cylinder force. But the loader has a mechanical advantage over the cylinder. IIRC when I figured out the geometry of my similar sized loader, each psi was equal to roughly a pound of lift for the total system. My loader has 1.77" bore cylinders.


Not that I frequent the deere section much, but I dont recall any threads about a 3320 having a weak loader??

 

[J_J]

There is no mechanical advantage in the lifting cyl.

If you had a cyl pushing perpendicular to the cyl base line, 90 degrees, then you have max force.

Using the 2in bore and 1 in shaft at 2500 psi, at 90 degrees = 7,854 lbs.

Any angle less than 90 is a decrease in force. Using an angle of 45 degrees, you would have a force of 5,556 lbs.

An angle of 30 degrees = 3,927 lbs

The higher you lift, the less force you can lift, based on the geometry of the lift arms.

As many people have experienced, you might be able to lift a certain distance, and then it quits, where you are at your limits based on the angle and the pressure. Sometimes you can tilt the load back over the lift pins and gain some force.

 

[LD1]

I am refering to the mechanical advantage of the loader over the lifting cylinder.

A 200 PSI loss may cause a 608# decrease in force in each of the cylinders. But in a typical loader, that isnt 608# of lifting force lost.

If his tractor makes 2500psi, and has a loader rated to lift 2000 lbs, it may take ~500psi just to lift the dead weight of the loader. Leaving 2000psi to lift 2000#. Roughly 1psi = 1# of lifting force.

I think you are talking about strictly cylinder force. Whereas I am talking about the rating of the loader at the bucket pins.

Since his loader is rated ~2000lbs lift to 59", loosing 200psi on a 2500psi system (8%) wouldnt cause him to loose 30% of his rated capacity.

 

[Kernopelli]

LD1... I think you are making an argument for exactly what JJ explained. Yes, in the first examples JJ gave, the cylinder itself loses a total force of 608# with -200PSI. In JJ's original statement there is no "mechanical advantage" to the cylinder itself other than and increase or decrease in PSI x area, either one equals a finite number....period. He never said exactly what the FEL would lose at -200PSI, that PSI/force figure was clearly related to the cylinder only. He went on to say. " Yes, a larger cyl will increase the force" ( of the cylinder and obviously to the loader as he explained how it could effect the tractor)..... he never said EXACTLY how much the Deere's FEL lift changed, only a larger cylinder at the implied same PSI increased force. It seemed clear/ easy to understand to me. You are saying the geometry of the loader effects the actual capacity of the FEL, which is correct... exactly what JJ explained. I think you are both explaining the same thing using different wording.

To the original question the OP had: Yes, cylinder ends can be changed. If the rod end is threaded a new threaded end can be screwed on. Otherwise, a welder and means to cut the ends is all that is needed. Last week, I changed my backhoe's factor 3" cylinder with swivel ball ends to an aftermarket 3.5" cylinder that came with DOM tube ends. I cut the ball ends off the OEM cylinder and cut the tube ends off the factory cylinder. I then welded the ball ends to the new, larger cylinder. Worked great!!

Here is a TBN link to a similar Deere FEL cylinder update http://www.tractorbynet.com/forums/build-yourself/186398-upgrading-john-deere-loader-cylinders.html. He has great youtube links to the entire project.

 

[LD1]

A decrease of 200 psi will cause you to lose about 608 lbs. of lifting weight.

When he said this, rather he meant it or not, I took it to mean what the loader could lift.

Now I know I aint very good at explaining things all the time. But was just trying to clarify that what he said is NOT what the loader would loose in lifting ability. Rather, that number is roughly what a 2" cylinder would loose in push force by being 200psi low. And that if the loader is indeed equipped with 2" cylinders, the actual loss of lift at the bucket would be roughly 1 pound per 1 psi.

 

[J_J]

Those figures I posted were for one cyl, so with two cyl you actually have more of a loss.

The cyl bore size and shaft size were hypothetical as I don't know the exact size.

There is always a disadvantage in lifting force unless you are lifting perpendicular to the lift arms.

What comes after that is the fulcrum effect where the further you go past the lifting point you lose lifting potential.

The only time you would ever have a mechanical advantage is if you were to lift something between the fulcrum point and the lifting point, and tractors loaders don't do that.

Then you have the length of the bucket lip which is out past the pin lifting point.