3-Point Hitch No lift in 3-point hitch

[LD1]

If you are in the bottom hole currently, just moving to the top will make a large increase in lift capacity.

But note, it will also keep the forks more level when raising, instead of the tips raising alot higher than the heals

 

[Leejohn]

Her pins for the lower link are on the inside,way high and top link to high, so I'm guessing that is a cat2 forks. Also look at how heavy the frame metal is. Top link should be 17" up from the lower link arms. and if the tractor is the same the forks well lift level. Do what Ld1 said about lowing the lower link and top link and put the top link in the upper mounting hole on the tractor. Then like tig and someone else said about moving the lift links back about 4" by drilling new holes in the lower link arm. I would also maybe be looking for a cat1 forks, they would be less then half of the weight of the ones you have now.

 

[Egon]

Drilling new holes farther back on the lower lift arms will give a better mechanical advantage. Just as is stated on the one diagram.

The top link does not effect the amount that can be lifted. It does change the tilt of the three point attachment.

Changing, lowering/raising, the bottom lift points on the three point attachment does nothing for total weight lifted. Adjustments here can be accomplished by changing the lift arm spline position.

 

[LD1]

The top link does not effect the amount that can be lifted.

Is certainly does. The part of an implement (or haybale) near the 3ph itself is gonna raise the same height off the ground no matter the toplink configuration.

The bottom hole is gonna raise the part fartherst from the tractor MUCH higher. And the top hole is gonna raise it not as high.

Given the same range of travel for the hitch itself, and same force supplied to it (input) the hitch is only capable of doing a specific amount of work. If that work involves lifting something higher, the weight is gonna be less. Lift the object not as high, and you can lift something heavier.

 

[Egon]

It just effects the tilt of the three point implement.

The bale gets tilted more or less.

 

[LD1]

It just effects the tilt of the three point implement.

The bale gets tilted more or less.

I know we have hashed this out many times before on TBN.

YES, it effects the tilt.

TO tilt one end more means lifting that *** HIGHER. That requires MORE force to do so. Since the 3PH only has a limited amount of force it can input into the equation, the MAX that can be lifted is LESS you you are set up so the tail rotates high into the air, vs setting it so there is no rotation at all. There is no free lunch.

Lets use the OP's pallet forks for example. Appear to be about 48" long. IF setup with the toplink in the top hole, the total range of movement for the tips of the forks may be 24".

IF in the bottom hole, the total range of movement may be alot more. They are capable of raising higher and lowering lower. Lets say 36".

Do we agree to this point?

IF so, how can you possibly say that the force required to lift and object 24" with the forks in the first setting is the same as it is to raise the object 36" in the second setting?

They are not. It takes more force to lift something a farther distance. IF force is limited to a specific amount (like in this case), the weight of the object must be reduced to lift the further distance with the same given input force.

I was trying to avoid these arguments and hijacking this thread, because bottom line, it dont do anything to help the OP's situation. If she wants max lift force, use the top hole. THe bottom hole is gonna lift less weight, but will lift it higher.

You cannot have both max lift height AND max lift force. Its as simple as that. Less height = more force. more height = Less force

 

[Egon]

Yes, on the top holes the end of the bale spear will lift higher. It's also higher before lifting. You might not be able to spear the bale due to it's angle.

It is the point at which the lift arms are attached to the lower arm that determines the height of lift as well as the weight of lift possible. Stated on one of the diagrams posted.

Starting out with the bale spear flat the arc subtended by the spear tip remains the same. The distance does not vary. Moving the lift arms into the near or farther position on the bottom arm will alter the length of arc of the bale spear tip. You will note it is still the same arc as the pivot point is fixed is it not. All that top link does is change the angle of the arc.

Note: if you can vary the the length of the top arm on the go you will gain a slight advantage by shortening the top link as you lift. The implement is now rotating around the bottom pivot point of the lower lift arm. The shortening makes for a slightly shorter lever arm in total. But this will not apply with a fixed link length.

I'd also surely hate to see the OP get incorrect instruction.

Oh; with a fixed length top link it will lift a slight amount more in the bottom hole if the load is spread evenly over the length of the bale spear!!

 

[LD1]

The arc does not remain the same.

In fact in the top hole, its a near parallel lift. The forks will remain almost level through out the entire range.

In the bottom hole of the toplink, the angle change through out the range of travel is MUCH greater. The tips of the forks travel a greater distance. So whatever weight that is on them is also traveling farther.

To lift 1000# 20" takes more force than lifting it 10".

What part is confusing? It sounds as if you do not believe changing the toplink location causes a different total length of travel that the tips are capable of. Is that correct?

 

[Egon]

Draw a picture.

The forks being parallel is about the length of the top link.

Lifting 1000 # twenty or ten inches requires the same force.

It's not confusing to me!

 

[LD1]

Do you have a tractor Egon? With multiple places for a toplink to attach?

If so. Do this. Put it in the bottom hole and adjust so forks are level. ( if you don't have forks, use whatever you got.) So level and on the ground we I'll call 0 degrees. Now raise all the way, and see how far off 0 it is.

Do the same with the toplink in the other holes.

Top hole, angal changes far less through out the entire range.

Bottom hole, changes a lot.

When using the forks, lifting AND angling a lot results in a lot more movement of the load, with an equal movement of the hitch.

My previous example about raising 10" vs 20" requiring different forces, that is assuming the same movement of the 3ph. Thin of lever ratios. If the hitch moving 10" causes the fork tips to move 10" that will have more power than if 10" of movement resulted in 20" of fork tip movement.