Oversized cylinders on my ck2510

[Zmann.]

I really had no use for the larger ck2610 and while researching I had thought the ck2510 would handle a heavier pallet than it actually could
hydraulic wise not counterbalance since having a backhoe makes that a non issue

the only reason I needed a little more FEL lift is once in a while I can rent my tractor out to my company instead of renting a forklift
but after trying a few things around the house like loading a 600 lbs safe into a 2' high trailer and just barely getting it up high enough
and then trying a few pallets with 400-500-550 lbs to see how high i could go I realized that this was not going to work for unloading pallets from a semi

I did bump the hyd psi by 250 psi but no help so I started looking around and found some Magister ready to ship 2.5 cylinders with a 12" stroke that were close to what I needed , I had to cut off and reclock/space the end tube and the worst part was the sae to british threads I had to get new lines made to do the transition
anyway when I was done there was not one of those pallets I could not lift to 50" with ease and even lifted the front of a vehicle off the ground that I had tried before and couldn't budge

we should all know this kind of modification is at your own risk, and you really need to pay attention to ballast and front tip potential not to mention you may be exceeding other structural limitations as well and the whole FEL assembly could collapse and impale you.

lift speed and lower speed was reduced minutely , but I always thought it was too fast anyway and this is more controlled

my tractor has 340 hours and I just bought it so I do not know if lift capacity has diminished since new but the hyd psi is just over spec
the FEL would bleed down overnight when i tested it and one cylinder had a slight drip but no damage.

now the FEL will maintain height overnight ,, if that even means anything ?

 

[Everhard]

I'm surprised there isn't a crazy long slew of replies here lol! Both the kind interested in what you did and those condemning the whole idea... (Although you clearly outlined all the dangers!)

Sooo all that aside, I'm curious to know how it's been working for you, have you done any tests to see what weight you can lift to what height? As I sit here typing away I'm pondering the physics behind it - I'm guessing a cylinder with the same range but larger diameter will lift more while being slower? (Is that an accurate statement?) If so it would be interesting to know the specs of the stock cylinder in comparison to what you put on. Exactly how close are the open and closed dimensions? Just wondering if you lost any height?

I previously had "boxes" of firewood (a pallet with 2 pallets vertically on 2 ends filled with firewood between the vertical pallets, with a 2 straps at the top to hold the vertical pallets from folding out.) - I don't know the actual weight but with even when the hardwood was seasoned the loader at best could just get it off the ground (CK20s) a little bit while using the 3 point hitch to lift them was no problem - So I know it was less then 1400lbs... My forks - I had made my own pin on that I would swap my bucket off to use - the design maximised the limited lift capacity - one of my beefs with these small tractors using the stock skid steer QA options out there. In the end given I had to stack pallets I made the top layer about a foot shorter and that the loader could lift up at least 4 feet or more - I never tested the max. Having said all that... I tried to not travel too far carrying a full load like that, in general I try to limit that as it puts a strain on everything loader, axle etc. But like you I am not against the idea of just a little more...

Last thought! The Ck2610 - Originally comes with the KL2610 loader which has a max capacity of 1252lbs BUT from the dealer you can instead get the same tractor with the KL4010 loader with a max capacity of 1835lbs! So in that case Kioti actual warrants the tractor to be able to lift more which is no surprise given between the models in that line-up the only real difference is the motor - the tractors are all physically the same otherwise. My point being that your increasing the capacity of the loader on the CK2510 might still be within it's actual capacity. (I say might given we don't have actual numbers here.) Personally given how beefy the CK2510 is I think it could safely lift say 200lbs more - with the proper counterweight.

Anyway, like I said at the start of this diatribe I'm interested to hear how things are working out...

E.

 

[JoelD]

I’d be super concerned about front axle, bearings, cv joints, etc. big money once broken. Not to be a Debbie downer but fork lifts have their place as you know and SCUTS have their place.

 

[oosik]

Overload your equipment - something is bound to break. All you did was change the formula.

Good luck ............

 

[LD1]

The original cylinders were 45mm cylinders. So a pair of them at 2500psi has a push force of ~12,300 pounds.

You went to 2.5" bore cylinders and a pair of them have a push force of ~24500#

You have doubled the force the cylinders "can" exert on the loader...

That doesnt mean you now have double the lift capacity. If means you have MORE than double the lift capacity due to the static weight of the loader not also doubling.

In other words....you say that you could lift a 600# safe 2' high with the old cylinders. Lets say that those cylinders were reall capable of 900# and that 300# is what it takes to lift just the empty loader and pallet forks. SO you had to have 900# capacity to actually lift 600#.

You doubled that 900# and now have 1800# of capacity.....but the empty loader still only takes 300# to lift. So the result is yoy can now ACTUALLY lift 1500#.

So by doubling the force of the cylinders....you actually yield about 2.5x's more usable capacity.

For what its worth....most manufactures dont start using 2.5" bore cylinders until 50-60 horsepower utility tractors that weigh twice what your tractor weighs. I hope this is just a case of going overkill and you never actually plan on using the full capacity of the cylinders. You backhoe is no longer sufficient ballast to keep the @$$ on the ground. And when it comes off the ground, the entire weight of the loader and load as well as the entire weight of the tractor and backhoe is all all on the grossly undersized front axle and tires.

If you just need a few hundred pounds more capacity, and respect that, you should be fine. but even the 4010 loader kept it modest at just under 2" cylinders (50mm) which would have been about 24% more power from the cylinders and about 50% more usable capacity as opposed to the 250% more capacity you gave it.

 

[sandman2234]

I have considered doing just what the O/P did, for the added capacity, but haven't taken the time to do the math on the size required. I do know that if I did the change, and had previously upped the pump pressure, I would probably let the pressure back down to original status.
David from jax

 

[Buggs67]

You don't mention if you are using clamp-on pallet forks or quick connect forks. Using the clamp-on forks my lift is much reduced but with the way it sticks way out there I don't think I'd want to lift more. Too unstable. The forks are a once-in-awhile use so not important to me to lift more. With sufficient counterweight (BH) my FEL will lift a full bucket of river stone, gravel or wet soil.

 

[deezler]

You don't mention if you are using clamp-on pallet forks or quick connect forks.

It has SSQA on the loader, so only a dummy would still use clamp-ons.

I just upgraded tractors, for the main reason to gain loader capacity and obtain SSQA. But! I do have to say, having the compact forks that much closer to the tractor front end does make it a bit harder to see what I am doing.... Been jamming into a lot of pallet wood, still need to get better at my new controls.

 

[Everhard]

LD1 - some good info there, thanks. One question - so just because the cylinders are capable of pushing 24500# vs the stock 12300# is the hydraulic pump capable of getting the cylinder to that maximum? Showing my ignorance here - I understand that a cylinder would have a max it can push but I would have thought a pump would also have a limitation? And/or the hp required to drive the pump to hit that maximum on the cylinder? - Or is it simply as long as the hydraulic system is capable of maintaining 2500#pressure then based on the capacity of the pump it will in time get the cylinder to it's max?

 

[LD1]

You have to first understand flow and pressure and how those are created and how they effect a cylinder.

Hydraulic pumps don't make pressure. They make flow. Your tractor spec is 11.3gpm. I'd guess some of that is power steering flow....on a tractor your size it's usually around 7.5gpm for implement flow (loader, 3ph, etc).

That flow would be at PTO speed. These are positive displacement gear pumps so each revolution of the engine moves a given amount of oil each time. Barring any inefficiency, 1000rpm is gonna flow half the oil that 2000 rpm gets you.

With the tractor running at at PTO speed, you are flowing 7.5gpm no matter what you are doing. If you are doing nothing, you have no pressure. 7.5gpm is simply coming out of the pump and going back to the tank.

If you are doing something like raising the loader....7.5 gpm gets diverted to the loader cylinders and they fill up causing the loader to lift. A 12" stroke, 1.77" bore cylinder like your stock ones takes 0.127 gallons of oil to extend. There is two of them, so the time it takes your tractor to pump 0.254 gallons of oil is the time it takes to fully raise. Or about 2 seconds.

The new cylinders at 2.5x12 take double the oil to do the same thing....thus twice as long. In other words, the cylinders...to get double the power, move at half the speed.

That's the effect of flow on cylinders. Flow = speed. More flow is faster. Less flow is slower. That's why idling down make things move slower.

Now pressure. Remember the pump only makes flow. Attempt to stop that flow and you build pressure. Trying to raise something with the loader is an attempt to stop the flow...so pressure builds. One of two things happen ...either it builds enough pressure to lift, or the relief valve opens to protect the system.

Without a relief valve, there is no limit to the pressure it will build. Remember...every revolution of the pump HAS to move that given amount of fluid at a rate of 7.5gpm. without the relief, pressure will build until something can no longer contain the pressure and let's go to allow fluid to move. Maybe a blown hose, crack the pump, etc. The relief valve is the intentional weak link in the system....usually set somewhere around 2500psi so bad things don't happen.

So with that said, you have a contained system capable of 2500psi. A hydraulic cylinder has a round piston that 2500psi pushes on. Figure the area of the piston....(pi x r-squared) and now you have the max capable force the cylinder can push with.

By going bigger, you have doubled the area of the piston, this doubling is capable force. The pump and relief have no idea what size the cylinders it's supplying are. It simply moves fluid at a given rate, and the system relief won't let pressure exceed 2500,psi. Do there is no other protection for your machine to prevent you from trying to lift way more than intended.

Let's say your max with the old cylinders was 600 pounds on the forks. That weight cause the system to need all 2500 psi to lift.

With the new cylinders, you can lift that SAME load with only half the pressure. Which means you have 1250 psi to spare to lift even heavier stuff. Which isn't a bad thing, and not a huge concern if you are only lifting pallets of known weight because you can know to be cautious. The issue would be doing something where you have no idea how much force you are exerting....like digging in the dirt, or trying to dig out a stump.

Sorry for the novel.....are you even more confused or do you understand?