Dynamic Rear Weight

[npalen]

A question comes to mind after reading some very interesting threads on adding weight to the 3PH. Would it make sense to build the weight system so that the attachment point of the toplink would cause the weight to tip back when the 3PH is raised? I would envision a fairly tall weight configuration such as, for speaking purposes, a 30 gallon barrel full of whatever. An unusually long top link would cause the tipping action with the advantage being that the weight could be lowered and tilted forward when it is not needed. This would transfer some weight back to the front of the tractor.

 

[swick1]

That would work great if you only drive on a concrete pad. The further it hangs out there the more likely it is to hit something. Members with backhoes will agree. Just buy a hoe

 

[npalen]

I was thinking that the only time the weight would be "extended" is when it's needed to counterbalance an unusually heavy load in the FEL bucket. The rest of the time it could be left in the "retracted" position for clearance. A hydraulic top link would provide or add to the same effect.

 

[swick1]

Yeah but it would need to swing from side to side if it sticks out that far and you drive on uneven terrain which is why I said a backhoe is a great counterweight.

 

[npalen]

Yes, I agree that a backhoe is a great counterweight but not everyone has one. I guess a TnT would accomplish the swinging side to side that you mention unless I'm misunderstanding.

 

[Gary Fowler]

I cant see you getting much dynamic force from anything that you could put back there. You are limited by the lifting force of your 3 PH. Then you are limited in the backward offset by the amount of clearance from the ground. You have to be able to pick it up by some amount so it doesnt drag the ground and most 3 PH arms only move 18-24". Allow 4" ground clearance and that only allow 20" of offset behind the pins x 1000 or so in weight and some of that weight will be above the pin and will therefore transmit it weight forward but still behind the wheels so assume 80/20 split so about 800# of dynamic force moving 14-20" behind the pins.
Any of you engineers want to calculate the additional force that this would apply to the rear wheels? Dont forget to subtract the 20% that is moving in front of the pins so that leverage is then lessened

 

[swick1]

Just find out where the center of mass is in all positions and multiply the horizontal distance between it and the axle center to find the torque exerted on the tractor regardless of how the counterweight is shaped.

 

[swick1]

Yes, I agree that a backhoe is a great counterweight but not everyone has one. I guess a TnT would accomplish the swinging side to side that you mention unless I'm misunderstanding.

Yes I agree with both points. If you have tnt though I think the tractor should be big enough to handle a large static counterweight. For my tractor in tight spots I was actually going to go the other way with a much heavier counterweight tucked in between the arms rather than slamming my hoe into everything.

 

[LD1]

I have to agree with the other posters that it just inst going to create enough of a change to matter.

The limiting factor is that the lower links are a fixed length and can only raise a given height. And the 3PH raises in an arc. So the higher it raises (normally) the closer the implement comes to the tactor. With a top-heavy weight and a long toplink like you are suggesting, I dont think it will gain anything on the raise. Maybe just enough to offset the the arc travel of the 3PH. Just make the counterweight heavy enough to start with

 

[SSdoxie]

I have to agree with the other posters that it just inst going to create enough of a change to matter.

The limiting factor is that the lower links are a fixed length and can only raise a given height. And the 3PH raises in an arc. So the higher it raises (normally) the closer the implement comes to the tactor. With a top-heavy weight and a long toplink like you are suggesting, I dont think it will gain anything on the raise. Maybe just enough to offset the the arc travel of the 3PH. Just make the counterweight heavy enough to start with

I too agree. Plus I think having a top heavy weight like this may add to risk of roll over on a side slope versus working to hold both rear wheels down.