Lift Capacity @ 24" for SubCompacts

[MARKMILES77]

Hello All from Australia

I have no experience with tractors and am looking at buying a sub compact tractor for my 2 acres. I have a question about rear lift capacity on the MF GC2400.
Browsing the MF website I notice that they list the GC2400 lift capacity @ 24" behind the ball ends at only 550 Ibs which is significantly less than any of the other sub compact tractors.
The MF "compare" webpage for the GC2400 lists the following stats for rear lift capacity @ 24":

Boomer 1025 700lbs
JD 2305 680lbs
Kubota BX2360 670lbs
MF GC2400 550lbs
These are the figures given by Massey Ferguson so presumably they know the capacity of the GC2400.
Even the little CubCadet has a lift around 670lbs.

The lift capacity for the GC2400 at the ball ends is 1191lbs which is more than the BX2360 at 992lbs
How can the GC2400 have more lift than the BX2360 at the ball ends but significantly less at 24" behind the ball ends"?

Which figure is more important for carrying stuff on the carryall, capacity at the ball ends or at 24" behind the ball ends?

Thanks for any replies.

Mark

Harkaway Australia

 

[art]

24" is often the center of the load or a more real number to work from for what it lifts!

That is in a perfect world. But what's perfect! I don't think that you will be trying or should be trying to lift more then 500lbs on a tractor of that size on the three point.

I am aware that things are different Down-under but not by that much!

 

[arrabil]

24" is the important figure for your carryall.

I would be concerned about this too. Makes you wonder whether its because the tractor is lighter, shorter, built less heavy duty, less hydraulic flow, or what? It could be an innocuous trade-off in design features or it could be a sign that its not as rugged. The rest of the specs might clue you in as to which.

Unlike art says though, if they say it can lift 550#, it can lift 550#. They didn't come up with this number to get sued over it later. Keep in mind, the maximum lift may not be on a stock tractor. They may have front ballasting requirements to achieve it (200# on the front or something similar). Or you may need the ballasting just because you're not running on flat ground.

 

[BruceWard]

It may be due to the angles chosen for the 3 point linkages on the various tractors. A change in angle from the lift arms to the lower links could change the lift capacity at 24".

All of those are light tractors. You will likely need weights on the front or a full FEL bucket to avoid lifting the front wheels.

 

[Don87]

deleted

 

[LD1]

It may be due to the angles chosen for the 3 point linkages on the various tractors. A change in angle from the lift arms to the lower links could change the lift capacity at 24".

All of those are light tractors. You will likely need weights on the front or a full FEL bucket to avoid lifting the front wheels.

This is the answer.

It all has to do with how each has designed the 3PH geometry. Mainly, where the actual lift points are on the arm itself in relation to the ball ends, where the link hooks to the tractor, and its relation to 24" behind the ball ends.

I am bored so I'll give you an example.

First, so we are on the same page with the termonology. There are 3 points that come into play on the lower 3PH arm. They are the point where the arm is affixed to the tractor, the point at which the lift arm connects (usually about half way between the tractor and the ball end) and then the ball end.


So... lets say that the lower arm is exactally 24" long and the lift point is right in the middle @ 12". For a rating of 1000lbs @ the ball ends, this would require an actual lift @ the vertical lifting arm of 2000lbs. Using that actual lift force, this would give a 12/48 (or 1:4) ratio @ 24" back. Or 500lbs.

Second example, Lower arm is lengthened 6" and the actual lift point is still 12" back from the tractor. Giving 18" from the lift point to the ball end.

In order to maintain the 1000lb rating 2 the ball ends, this would require a lift force on the arm of 2500 lbs. Now @ 24", which is actually 54" away from the tractor, we now have a 12/54 ratio. Multiply that be the 2500 lbs and you have 555lb rating @ 24".

This is somewhat of a crude example of how two tractors can have the same or similar rating at one point and differ at another.

 

[arrabil]

It all has to do with how each has designed the 3PH geometry.

That means the manufacturer is actually at fault if their tractor lifts less than another model. So I doubt this is the reason. No way would any of the manufacturers, including the chinese ones, give away comparable specs for something as simple as a redesign of their three point geometry. Cause if MF could outperform Deere or Kubota just by changing some points, they would.

No, it has more to do with front/rear weight distribution, tire selection, safety margins, frame design, frame materials or castings, tractor length or weight, hydraulic pump capacity, etc.

 

[LD1]

That means the manufacturer is actually at fault if their tractor lifts less than another model. So I doubt this is the reason. No way would any of the manufacturers, including the chinese ones, give away comparable specs for something as simple as a redesign of their three point geometry. Cause if MF could outperform Deere or Kubota just by changing some points, they would.

No, it has more to do with front/rear weight distribution, tire selection, safety margins, frame design, frame materials or castings, tractor length or weight, hydraulic pump capacity, etc.

Maybe, but none of those things you mentioned has anything to do with what I am saying. IF it CAN lift more at the ball ends, and less @ 24", the ONLY think it can be is the geometry.

Maybe they designed the geometry differently BECAUSE of the things you mentioned, of maybe it ACTUALLY can lift more, but they are de-rating for the reasons you mentioned, who knows. But if it can lift more force at the ball ends but less at 24", it is a geometry thing.

 

[arrabil]

IF it CAN lift more at the ball ends, and less @ 24", the ONLY think it can be is the geometry.

Not at all. You're not taking into account that the rear wheel is a fulcrum. So if there isn't enough weight at the front of the tractor, 24" extra past the fulcrum point could make the weight distribution unsafe. So even though the power to lift more is there, the counterbalancing weight is not. And that has nothing to do with the 3pt geometry while directly impacting the lifting capacity.

 

[LD1]

Not at all. You're not taking into account that the rear wheel is a fulcrum. So if there isn't enough weight at the front of the tractor, 24" extra past the fulcrum point could make the weight distribution unsafe. So even though the power to lift more is there, the counterbalancing weight is not. And that has nothing to do with the 3pt geometry while directly impacting the lifting capacity.

I already said it may be de-rated to a lower number for the reasons you mentioned, which is exactally what you are saying. If it can't ift to its full potential, (max PSI) add weight to the front until it can.

If they are rating it lower than what the hydraulics can lift, that is de-rating it. If it is rated that low because that is the most the hydraulics can lift at the operating pressure, then it IS a geometry thing.