Lift Capacity @ 24" for SubCompacts

[LD1]

Do a Google search and find me anywhere that says a three point is a parallel linkage. Literally the only results are you guys talking about it. I may be wrong, but you have yet to prove it other than by saying it. None of your numbers pan out, none of the ASE specs agree, literally nothing agrees with you guys except you guys. Even on other tractor sites I find people who say what I say but not what you do. Do you have any links or refrences to "prove" this other than just you "saying" it

And when you search for parallelogram linkages, you don't get examples of a three point hitch. So instead of saying I don't understand it.... prove it with something official.

It is simple numbers. The measurments and numbers side with us.

I really wish a volunteer that has a large enough spring scale or carryall and some cement blocks that had some free time to do the expirement that I suggested a few pages ago. That would put all this to rest and prove once and for all who is right.

 

[tsteahr]

ASE Standard S127.12. If the 3pt hitch was supposed to be a parallelogram linkage, why would they specify a minimum vertical convergence and mast height?.

It is not a requirement that any links must be parallel. Take a look at figure A1 of your ANSI link. Distance 5-6 does does not have to be equal to distance 3-4. It could be, but it does not have to be. Distance 3-4 at the implement can vary from one implement to the next, and distance 5-6 can vary from tractor to tractor. Often both the tractor and the implement can have more than one option for connection points.

The ANSI standard DOES NOT specify a minimum mast height. It specifies a specific mast height range for a given implement category. It is not a open ended specification. Refer to Table 4, height with a plus/minus tolerance. This is to maintain reasonable geometry compatibility with like category implements. Compatibility is a primary reason for all ANSI standards.

Also, note 0.6 makes an interesting point on why the top link is there. Doesn't say anything about improving the lifting characteristics that I could find.

It is not the purpose of an ANSI standard to maximize any particular lift characteristic.

In fact, I can't find a single word about maintaining the parallelogram or the linkage lift integrity in the entire spec. If it needed to be as close to a parallelogram as possible, surely they would try to maintain something as close to one as possible. As opposed to specifying the exact opposite anyway.

There is a passing reference to linkage position and its relation to lift performance. Please read item 0.6 of the Forward section. I have copied it below:

0.6 Upper link attaching points: ISO 730-1 recognizes that implements
worldwide can generally be divided into two classes; 1) those requiring
near parallel lift and 2) those requiring maximum tail clearance when fully
raised. Clause 4.1.2 for these reasons specifically requires two different
upper link points on the tractor.


This section aknoledges changing upper link points impacts 3ph characteristics. IE max height of lift or parallel lift for best force distribution and/or implement performance.

This evidence is in front of you, if you choose to open your eyes.

 

[MFRED]

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

I would just hook something up to the 3pt & try it. Numbers on a sheet or the internet lie as much as the people putting them there. Though it's stated to be equal across the board, the standard for the ratings can be manipulated any way one wants them to look.

Just because a machine is rated to an extent or class, doesn't mean it should be run there.
We all know that loader lift capacity doesn't mean squat without proper ballasting. Same goes for rear mounted implements as well.

A lift capacity of 500 pounds doesn't mean squat if that 500 pounds is a rotary cutter that sits 4ft behind your tractor. How much is the weight at that 24"? Honestly, I don't know, and I'm certainly not going to waist my time figuring it out.

But I can tell you if the tractor can pick it up & if it's safe to do it or not.
I've run tractors with 5,500 lb lift capacity that are down right scary to move when lifting a 3,000lb rotary rake. (3pt mounted of course!)

Back to the original question. I think any of the tractors would be more than sufficient, I don't think the capacity of the 3pt lift would be exceded before the carry-all got full of stuff, or the front end got too light.

 

[arrabil]

Yup, still haven't seen anything. And yes, my links can all be found on the first two pages of a google search "three point hitch parallelogram". You can substitue link for hitch too.

 

[tsteahr]

Yup, still haven't seen anything. And yes, my links can all be found on the first two pages of a google search "three point hitch parallelogram". You can substitue link for hitch too.

Arrabil,

Did you read the ANSI standard you posted? Did you look at the figures? Did you read the tables? The text? Did you attempt to comprehend what is published there? It shows they don't have to be parallel. It describes the reason for different attachment points.

I'm confused that you can post something, refer to something when it provides the opposite of what you are saying.

 

[arrabil]

Huh? If the toplink need not be parallel and it's not attached to the lifting apparatus then how can it be a parallelogram linkage?

 

[nunyabinis]

From my 3038e manual:


For light and medium draft loads: Install center link (A) in bottom hole (B) of mounting bracket. Example of light and medium draft load implements would include a landscape rake. A category 1 implement will tilt forward while raising in this position.
For medium and heavy draft loads: Install center link in middle hole (C) of mounting bracket. Example of medium and heavy draft load implements would include a tiller or box blade. A category 1 implement will tilt forward slightly while raising in this position.
For very heavy draft loads: Install center link in top hole (D) of mounting bracket. Example of very heavy draft load implements would include a plow or ripper. A category 1 implement will raise, but angle will remain constant.



Pretty much spells out how it works.



.

 

[arrabil]

Here is another challenge for you all.... find me an example of a parallel linkage where one of the "parallels" is not directly attached to the powered part of it.

In every parallel linkage example I can find, both parallel members are capable of transferring the force. If one fails, the "level" cannot be maintained, but it can still transmit its force to the connected object. This is not true of the toplink. If the lower arms fail, the object is no longer under any force but gravity.

So if the toplink point was actually attached to an extension of the rockshaft arms, THAT would be a parallel linkage. And the current toplink would be unnecessary. And since the rockshaft arms aren't exactly parallel with the lower arms, that would be an imperfect parallel linkage too.

but angle will remain constant. Pretty much spells out how it works.

Sure does. Cause that is what the toplink is for. But it doesn't magically make it a powered component of anything as would be the case in a parallel linkage.

 

[tsteahr]

Huh? If the toplink need not be parallel and it's not attached to the lifting apparatus then how can it be a parallelogram linkage?

Please expand on what statement you are referring to.

EDIT: No one has said a 3ph linkage must be a parallogram. It can be parallel, but it does not have to be. What do you mean "it's not attached to the lifting apparatus"? The tractor is the lifing apparatus, the link is attached to the tractor and to the implement. Where is the confusion?

 

[SPYDERLK]

Yup, still haven't seen anything. And yes, my links can all be found on the first two pages of a google search "three point hitch parallelogram". You can substitue link for hitch too.

Perhaps youre using the wrong search words. "Three point hitch parallelogram" is not necessarily going to work with sources that use forward to mean foreword. ... Try parallelogram linkage, 4 bar linkage, parallelogram lift, weight cancellation devices, etc. The relation of a 3ph to them is as obvious as are commonalities of the human race.
larry