Calculated lost loader lift capacity with quick attach.

[3v0]

I have been reading about this here and else where. Everyone talks about it but I did not see any numbers.

Math was never my strong point so I hope I got this right.

Lets assume a small tractor loader like used on a Kubota BX is 60 in from the rear pivot pin to the bucket. The lift spec is 500 lbs. This gives us 500 * 60 or 30,000 in lbs of torque at the arm pivot. This figure will stay the same.

Now lets extend the lift point by 6 in to 66 in by attaching a quick attach setup. Our new lifting capacity will be 30,000 in lbs / 66 in or 454.5 if we ignore the weight of the adapter. 454/500 is 90%. This also makes sense in that we increased the distance by 10% so the drop in lift capacity is 10% but we should also lift 10% higher.

But add the weight of a 70lb adaptor and we are down to a 385.5 capacity or about 77% of what we started with.

I need to get the tape out tomorrow and see what the actual length of the loader arm is.

 

[Don87]

I have been reading about this here and else where. Everyone talks about it but I did not see any numbers.

Math was never my strong point so I hope I got this right.

Lets assume a small tractor loader like used on a Kubota BX is 60 in from the rear pivot pin to the bucket. The lift spec is 500 lbs. This gives us 500 * 60 or 30,000 in lbs of torque at the arm pivot. This figure will stay the same.

Now lets extend the lift point by 6 in to 66 in by attaching a quick attach setup. Our new lifting capacity will be 30,000 in lbs / 66 in or 454.5 if we ignore the weight of the adapter. 454/500 is 90%. This also makes sense in that we increased the distance by 10% so the drop in lift capacity is 10% but we should also lift 10% higher.

But add the weight of a 70lb adaptor and we are down to a 385.5 capacity or about 77% of what we started with.

I need to get the tape out tomorrow and see what the actual length of the loader arm is.

You are going to be one busy fella for a while.

 

[stuckmotor]

A friend told me that the problem with overloading a FEL was breaking wheel rims and spindles. Has anyone ever done this?

 

[texasjohn]

No
You can chain a FEL down to the ground so it cannot move. One of the following will happen when you lift:

Rear wheels will come off ground...do be careful and don't carry this experiment to its conclusion...a tip over
Hydraulic relief valve will pop...you hear a hissing sound, know tractor is trying to lift, but rear stays on ground because lots of weight back there.

Rims will not break. Spindles will not break
If you have low tire pressure, a loaded bucket, turn sharply, then likely you will roll the tire off of the rim. Carry near max pressure in tire to avoid this mistake.

A friend told me that the problem with overloading a FEL was breaking wheel rims and spindles. Has anyone ever done this?

 

[yanmars]

I have a 33 horse tractor that had the spindles break. They were known for that. I got the larger refit spindles and have not had a problem since.
I would surmise that a heavily loader bucket, traveling at some speed over rough terrrain could cause spindle damage.

 

[stuckmotor]

I took my friend to mean that the breakage occurred over time, due to metal fatigue. He said that the rims broke first. I also took him to mean that after replacing the rims, the spindles broke.

I have a 33 horse tractor that had the spindles break. They were known for that. I got the larger refit spindles and have not had a problem since.
I would surmise that a heavily loader bucket, traveling at some speed over rough terrrain could cause spindle damage.

 

[texasjohn]

Just my opinion, but broken spindles or rims would be either a design specification or manufacturing defect....tractors and FEL's are built to be used with reasonable care but to not be babied.

 

[stuckmotor]

I think you are correct and posted the question to verify this. I recently acquired my first tractor with a loader and am trying to avoid problems.

Just my opinion, but broken spindles or rims would be either a design specification or manufacturing defect....tractors and FEL's are built to be used with reasonable care but to not be babied.

 

[texasjohn]

First problem to avoid is to make sure you have sufficient rear weight to keep tires firmly on ground when carrying max FEL load (so heavy you can only lift FEL load a foot or so). Won't carry this weight often, perhaps, but when it happens you want to avoid tipping forward. Next thing to do is ALWAYS keep FEL load low...again to reduce tipping risk. Do this and you avoid two common newbie operational mistakes. Reading the safety forum will teach you a lot if you haven't already done so.

I think you are correct and posted the question to verify this. I recently acquired my first tractor with a loader and am trying to avoid problems.

 

[3v0]

Just my opinion, but broken spindles or rims would be either a design specification or manufacturing defect....tractors and FEL's are built to be used with reasonable care but to not be babied.

I agree. My thinking is that if you put too much loader on a tractor you might bust it up. But if you use the loader spec'ed for the tractor you should not have a problem.