Lift Capacity @ 24" for SubCompacts

[tsteahr]

arrabil,

Having read your posts on this subject, I have concluded that you are not a mechanical engineer. Correct me if I am wrong. There is more than one engineer on this site. It is presumptuous to insist to a engineer that they are wrong concerning a subject in their field, when you yourself are not schooled in that field.

An analogy would be if you were a medical doctor I and continued to insist that I have a better understanding of medicine than you even though I am not educated in the subject. It is disrespectful to the individual who has devoted years of study to the field and it is disrespectful to the discipline. It trivializes all the work that was done by brilliant historical scholars developing the discipline and it presents yourself as being so brilliant that you know more on a subject than the combined knowledge of a number of individuals that have been extensively schooled on said subject.

 

[arrabil]

and because a 3ph is definitely a //ogram link application.

Its only a parallelogram in order to maintain object orientation! Not because it provides mechanical advantage or takes away mechanical disadvantage. Otherwise you'd find a smaller tractor company pushing the limit and at least advertising 90% at 24". Its a lever/fulcrum for lift and a parallelogram for orientation. And every manufacturer's spec sheet numbers fall in line with that.

 

[arrabil]

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?

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.

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.

 

[chipsndust]

I love this forum!

 

[MARKMILES77]

AGCO Compare



This is the MF page that triggered my question.
Click on the "Hydraulics (Standard)" section and then click on the "Manufacturer" choices and add the John Deere 2305, New Holland 1025 and Kubota BX2360 or whatever you desire to see the difference.

Interestingly, if you put in the John Deere 2720 you get the following figures:
Lift at Ball ends: 1433lbs. Lift 24" behind BE 1250lbs. Minimal degradation in lift capacity 24" behind the Ball Ends compared to the GC2400 which drops from 1191 to 550lbs!

Mark

 

[LD1]

Its only a parallelogram in order to maintain object orientation! Not because it provides mechanical advantage or takes away mechanical disadvantage. Otherwise you'd find a smaller tractor company pushing the limit and at least advertising 90% at 24". Its a lever/fulcrum for lift and a parallelogram for orientation. And every manufacturer's spec sheet numbers fall in line with that.

AGCO Compare



This is the MF page that triggered my question.
Click on the "Hydraulics (Standard)" section and then click on the "Manufacturer" choices and add the John Deere 2305, New Holland 1025 and Kubota BX2360 or whatever you desire to see the difference.

Interestingly, if you put in the John Deere 2720 you get the following figures:
Lift at Ball ends: 1433lbs. Lift 24" behind BE 1250lbs. Minimal degradation in lift capacity 24" behind the Ball Ends compared to the GC2400 which drops from 1191 to 550lbs!

Mark

Looks like its not a small compay pushing 90 percent but rather John deere itself. Actuall ~87% but close enough.

 

[nunyabinis]

A TPH is an imperfect parallelogram. Some tractors have toplinks that can be attached at multiple places on the back of the tractor to either give you greater lift capacity or greater lift height.

Operator's Manual for my tractor:

Operating


The bottom position "B" gives greater lift height (through rotation) of the implement. The top position "D" gives greater lift capacity by keeping the implement level (no rotation) as the implement is lifted.


If the TPH were a perfect parallelogram you could move the implement as far as you wanted from the tractor with no resultant loss of lift capacity. If you bolted the front of the tractor down so that it couldn't flip over backwards and started moving the load farther and farther back away from the tractor, something would eventually break. You would rip the toplink assembly apart or crush the drag links, so, for any given tractor, you are limited by the strength of it's given components.

 

[LD1]

A TPH is an imperfect parallelogram. Some tractors have toplinks that can be attached at multiple places on the back of the tractor to either give you greater lift capacity or greater lift height.

Operator's Manual for my tractor:

Operating


The bottom position "B" gives greater lift height (through rotation) of the implement. The top position "D" gives greater lift capacity by keeping the implement level (no rotation) as the implement is lifted.


If the TPH were a perfect parallelogram you could move the implement as far as you wanted from the tractor with no resultant loss of lift capacity. If you bolted the front of the tractor down so that it couldn't flip over backwards and started moving the load farther and farther back away from the tractor, something would eventually break. You would rip the toplink assembly apart or crush the drag links, so, for any given tractor, you are limited by the strength of it's given components.

This is exactally what we are trying to explain to arrabil.

However I think he has it set in his mind that he is right even though no one has yet to agree with his understanding and everyone else seems to agree with the rest of us.

I don't think there is anything we can do to change his mind at this point. I have tried explaining it and giving examples and comparisons and analogys to the best of my abilities. I guess it is a good thing that I am not a teacher because I would have failed.

 

[SPYDERLK]

arrabil,

Having read your posts on this subject, I have concluded that you are not a mechanical engineer. Correct me if I am wrong. There is more than one engineer on this site. It is presumptuous to insist to a engineer that they are wrong concerning a subject in their field, when you yourself are not schooled in that field.

An analogy would be if you were a medical doctor I and continued to insist that I have a better understanding of medicine than you even though I am not educated in the subject. It is disrespectful to the individual who has devoted years of study to the field and it is disrespectful to the discipline. It trivializes all the work that was done by brilliant historical scholars developing the discipline and it presents yourself as being so brilliant that you know more on a subject than the combined knowledge of a number of individuals that have been extensively schooled on said subject.

Well, Im not heavy on credentials and seldom state mine since I suspect its akin to posturing. You can tell when a person knows a subject pretty quick in sober conversation. Even experts will sometimes be wrong and a person with less training, but having well perceived experience, might be the one to set them straight. This can often come from reminding them of something they forgot to consider .. or filling in some blind side they have. I really dont mind extended disagreement as long as the underlying reasons for it are being developed. It is a chance to both learn and impart. It is only when one side continues to stubbornly rehash objections that have been allowed for and dealt with in explanation that the amusement turns sour.
larry

 

[arrabil]

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.

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.