Lift capacity of 3-pt hitch question (plz keep it simple)

[LD1]

Well you have said it is simple at least 3 times and others have said it is not simple even more times by multiple posters. The responders state that unless the variables are clearly defined and then the data is only valid for the configuration that is described there is no simple answer.

Since you don't seem to agree with the responders' position on their statement that it is not simple; there is a standoff.

Is that Clear and Simple?

:thumbsup:

When something is adjustable there is no simple answer. Not sure what is so hard to understand about that.

Maybe we need a chart with the 100's of possibilities. Kinda like they have in cranes?

How much can a 30 ton crane lift? Well, the answer isnt always 30 ton. Depends on the load radius (boom angle and height), and weather the load is ore/aft of over the sides. Since the boom can swing, go up and down, and extend/retract in lenght, the lift capacity is ever changing. Just like the 3PH

 

[Sodo]

When something is adjustable there is no simple answer. Not sure what is so hard to understand about that.

Then to actually help people you have to simplify the conditions. As in (plz keep it simple) For example, do it as simple as the Kubota spec.

OK back to post #23 I go. scrollscrollscroll,,,,,

BX is rated for 992# at the ball ends and 670# at 24" back

A conclusion is arises out of the fog of engineering ! Before page 4!

Kubota BX 2360 tractor rated @ 992 lbs, was able to lift appx 150 lbs of pallet fork attachment plus 800 lbs of cargo.

I guess the next question is, what if the bricks were moved 24 inches rearward? To the center of the pallet. Anyone have actual data? Does it max out around 670lbs 24" back? Is this reduction from 992 to 670 due to the front wheels rising off the ground? Or does the 3-pt lift stall out?

 

[SPYDERLK]

He wants to know how much a tractor rated at 1500# of lift will lift? Anyone have a tractor close to that that has lifted something to the max and knows what that weight was?

The answer is: It will lift 1500# at any point behind the eyes if you set your 3ph as a perfect //ogram. There will only be slight, and slowly increasing losses as you go back from the eyes due to the higher leverage of the weight on the pivot points.
larry

 

[LD1]

I guess the next question is, what if the bricks were moved 24 inches rearward? To the center of the pallet. Anyone have actual data?

The BX is a rare breed in that it only has one option for the toplink hole. So moving the load rearward can be calculated. By simply doing the measurements I have explained more than once. (or taking exact measurements of every moving part of the 3PH).

I dont have a BX, I dont have pallet forks. Therefore I will have to rely on others for that information. Since it looks from the pictures the forks do pitch up some (assuming the pallet forks were level when on the ground), there would be a reduced capacity the farther back the load is moved. (because the load would be lifting higher).

IF it were a tractor with more toplink positions, moving to a different hole could make the bricks lift higher; or not as high. Thus changing the capacity.

Also, forks are different. Especially homemade. Forks Not everything is made to quick hitch standards. So the toplink can be higher or lower on the fork frame, also changing capacity.

Using a set of quick hitches on the lowers like the carter ones that mount ON TOP of the lift arms, changes the effective lift arm angle of the lowers. This can also effect capacity.

Using a quick hitch moves the load about 4" further back, that also effects lift capacity.

Like I said, lots of variables effect how much it can lift. Having 1 person do a test with a quick hitch isnt gonna be accurate for someone not, or using carters or pats instead. Someone using a QH compatible set of forks vs someone using a homemade set to keep the lift level (like I suggested doing in the other thread) is not gonna be the same result even using the same tractor.

 

[Egon]

The answer is: It will lift 1500# at any point behind the eyes if you set your 3ph as a perfect //ogram. There will be slightly greater losses as you go back due to the increasing leverage of the weight on the pivot points.
larry

:thumbsup::thumbsup:

 

[bcp]

You probably can't adjust for a perfect parallelogram with level forks, for example. Usually the top link forward attachment point is farther to the rear than the lower link attachment point, but the implement pins are in a vertical line. Top links, even fully extended, are usually quite a bit shorter than lower links.

Bruce

 

[Sodo]

The tone of this thread has changed somewhat since Bruce's post. :thumbsup:

Having 1 person do a test with a quick hitch isnt gonna be accurate for someone not, or using carters or pats instead. Someone using a QH compatible set of forks vs someone using a homemade set to keep the lift level (like I suggested doing in the other thread) is not gonna be the same result even using the same tractor.

IMHO, Bruce's lift test, with pictures of the attachment, the cargo and the specs tells many folks what they need to know (probably close enough). Even though it looks to be about 12" behind the ball ends ( ! )

I still have questions where the 670# rating comes from. Certainly there are variables and more variables. An actual test at the front, then moved 24" rearward would be more interesting than further theory on variables.

 

[bcp]

I'll be doing some more block work later this spring, and will try different positions, if someone else doesn't do it first.

When I did the weight testing, I only wanted to know what I could carry, not experiment with hitch geometry.

Bruce

 

[LD1]

The tone of this thread has changed somewhat since Bruce's post. :thumbsup:



IMHO, Bruce's lift test, with pictures of the attachment, the cargo and the specs tells many folks what they need to know (probably close enough). Even though it looks to be about 12" behind the ball ends ( ! )

I still have questions where the 670# rating comes from. Certainly there are variables and more variables. An actual test at the front, then moved 24" rearward would be more interesting than further theory on variables.

No idea what kubotas limiting factor was when publishing the 670# spec. Was it the limits of the hydraulics? Or was the limit keeping the front end down?

Perhaps they tested with the toplink in the shortest possible configuration. And in order to attain level forks BCP had to lengthen it some increasing capacity.

Perhaps the estimate of the blocks and weight of the forks is off a bit. Maybe he was only lifting 800# @12" instead of ~950?

My "tone" remains the same. There is no simple answer. Even on the BX (while it is simpler) is still effected by several variables.

 

[SPYDERLK]

You probably can't adjust for a perfect parallelogram with level forks, for example. Usually the top link forward attachment point is farther to the rear than the lower link attachment point, but the implement pins are in a vertical line. Top links, even fully extended, are usually quite a bit shorter than lower links.

Bruce

You can use chain for toplink. ... But youre right about achieving level forks at the same time you try for a //ogram. That requirement complicates matters a great deal when you want to adjust for max lift capacity.
larry