Calculating FEL Lift Capacity

Xfaxman · Dec 6, 2016

davedj1 said:
OK, quick question before I continue. Is the relief in the valve that I am going to use what determines system pressure? This one is set to 2000 psi
2 SPOOL 8 GPM PRINCE MB21GB5C1 DA VALVE W/FLOAT

If you haven't already bought that valve, look for a 3 spool with float. The third spool would operate a grapple. :thumbsup:

gladehound · Dec 6, 2016

Fallon said:
All these calculations are missing one thing... The loader might not be the weak spot. There is a good chance your maximum loader lift capacity is actually based on your front axle or front tires. Personally I'd much rather go into relief, or blow a hose than bust my front axle. Blowing a tire with a heavy load could easily result in rolling the whole machine in many circumstances too.

Front axle testing..

In all seriousness, this is why I got an SSQA plate for the rear. The rear is designed to handle higher loads for a longer duration than the front end. Plus it's more stable to carry on the rear.

LD1 · Dec 6, 2016

Fallon said:
All these calculations are missing one thing... The loader might not be the weak spot. There is a good chance your maximum loader lift capacity is actually based on your front axle or front tires. Personally I'd much rather go into relief, or blow a hose than bust my front axle. Blowing a tire with a heavy load could easily result in rolling the whole machine in many circumstances too.

I wouldnt say the calculations are missing anything.

Its calculating how MUCH the loader can lift at a given (MFG set) pressure. Front axle has nothing to do with it.

May the front axle be overloaded....maybe.
Might it break.....maybe.
Might the rear tires lift before you run out of hydraulic power.....maybe.

But non of that is factored when a MFG calculates, and publishes data for what a loader "can" lift. Has nothing to do with the tractor other than PSI. ITs all about the loader and what it "CAN" do. The MFG is gonna assume you use sufficient counterweight. And if a MFG has concerns of stability or front axle, they may lower the PSI to the loader.

But to put a loader "capable" of lifting 4k on a tractor, then only rating it at 2500# because they fear front axle damage.....they just dont do that, or rate them that way.

Xfaxman · Dec 6, 2016

Here is my front axle testing:

Added some rear counter weight. :thumbsup:

davedj1 · Dec 6, 2016

Xfaxman said:
If you haven't already bought that valve, look for a 3 spool with float. The third spool would operate a grapple. :thumbsup:

I haven't bought the valve and that exact thought had crossed my mind. In all honesty I really don't see me ever needing a grapple on such a small machine.

Xfaxman · Dec 6, 2016

Your tractor is probably bigger than my loader and there have been many times that I could have used a grapple instead of picking up brush by hand and putting it on the forks.

npalen · Dec 7, 2016

Would love to see a video of you getting on the Toro.

Xfaxman · Dec 7, 2016

npalen said:
Would love to see a video of you getting on the Toro.

Getting it is easier than it looks, Here is the explaination: http://www.tractorbynet.com/forums/...ter-put-together-post3205933.html#post3205933

gladehound · Dec 8, 2016

My 1,100 pound capacity hanging scale came today and I'm already wishing I had a 5000 pound rated scale (just didn't want to pay for one)! While it is possible to set up pulleys to measure heavier objects, the set up is cumbersome so I haven't tried to weigh anything really heavy yet. However, I did get some actual loader arm / attachment weights to shed more light on the loader lift capacity calculations (at least for my personal tractor).

My two 2.36" ID lift cylinders combined generate 22,350 pounds of force at 2556 psi. At ground level my moment arm is 14.125" and horizontal distance from loader arm pins to the SSQA pins is 65". So this gives me 4,857 pounds of vertical lift at the SSQA pins. But before my loader can lift anything, it needs to overcome it's own weight. And that weight changes all the time depending on what I have on the SSQA plate.

I was first curious how much the loader arms + SSQA plate weighed at the pin.

388 pounds (loader valve in float)! Less than I thought. So with no attachment, I should have 4,469 pounds of break out force at the SSQA pins. I can only assume that the difference between this number and the Kioti specification of 3727 is the allowance Kioti is giving either for attachments or perhaps for being under the pressure spec somewhat - or a little of both.

My forks use up most of that allowance, my 375 pound forks add much more than 375 pounds at the pins because (like any attachment) they are out past the pins. With the forks attached, My loader arms, SSQA and Forks weighed ~878 pounds at the SSQA pins (loader valve in float).

So with forks on, calculated break out at the SSQA pins is 3,979 pounds, much closer to the 3,727 spec.

I also have a 500 pound snow / mulch bucket and didn't weigh the loader arms at the SSQA pins with that bucket on but based on the results with the forks, it should come in very close to the spec Yet my stock bucket is lighter than the forks and gives me a little extra lift capacity.

I know of no standards for CUT loader specs. I wouldn't be surprised if different manufacturers measure different ways. For example, does the spec include an attachment, does it allow some cushion for pressure to be a little low etc. None of the manufacturers seem to tell how they measure it for CUTS. (although Kioti used to write something in their specs to indicate the bucket was accounted for in the lift specs but they no longer have that verbiage so don't know if it's the case for their newer loaders).

I'm pleased that my calculated numbers come out to be very close to the Kioti spec. It all "makes sense". Once I get the boom pole I may have enough scale (running one pulley) to measure actual lift at 9 to 11 feet past the SSQA pins. From that, can easily back calculate any distance from the pins. Will be nice to have an actual scale measured validation. And if the lift isn't there, it tells me that I'm under pressure and need to be brought up to spec.