Hill Climbing Primer

[SPYDERLK]

Those paragraphs in the NASD paper on Draw Bar Leverage explains thing right.

At least for the practical man ;-)

But Fig 5 "angle of pull" is totally bogus.

 

[SPYDERLK]

No Larry, I did not say that at all. I've never said that. You know I've never said that. I've always had the same position in this. My position is that when power is applied there is a lifting force on the front of the tractor. You've actually agreed to that position. You agreed to me and then you confirmed this to CalG. I can copy/paste your agreements, but I assume you know what you've said, as I know what I've said.

There's no need for you to "bold" print to me or to copy/paste several of your replies that have absolutely nothing to do with that position.
.
Larry, you know that what I've said all along is true and correct. And you also know that it has nothing to do with pull point. You've admitted that also.

You actually had yourself out from under this discrepancy. So are you now saying that is incorrect??

Sorry. I bolded to draw out the post I was making from those made prior. :confused3:
...I agree that there is a lifting force, but that it is offset by an amount according to the point where load is applied to resist forward motion. I think you will see that consistance in my posts. Perhaps I misunderstand what you mean. Let me ask ... Did you say this? :

Awww Larry,,,, I thought we had covered this already??

If the rear tires do not lose traction and the drivetrain has the power to continue to turn the pinion and the load does not move, the tractor will do a wheelie, "dont matter how low you hitch" That is a true statement and all of the analysis given by yourself and CalG proves it.

... What does it mean?

 

[ovrszd]

Sorry. I bolded to draw out the post I was making from those made prior. :confused3:
...I agree that there is a lifting force, but that it is offset by an amount according to the point where load is applied to resist forward motion. I think you will see that consistance in my posts. Perhaps I misunderstand what you mean. Let me ask ... Did you say this? :


... What does it mean?

It means exactly what it says. No loss of traction. Drivetrain with sufficient power to continue to turn. Load does not move. Tractor will do wheelie. Regardless of hitch point.

Your analysis proves that.

In reality we all know that if the hitch point is low enough these truths will not play out because the weight will be lifted off the rear tires and they'll spin.

But if all the circumstances I outlined above are met, the tractor will lift the front end. Everyone in this discussion knows that is true.

I wonder if the differences in this discussion might come from experiences.

I am pretty sure Egon and I base our statements on practical experience of hours in a tractor seat under a wide range of applications.

I'm not so sure what CalG and yourself base your statements on. But it appears it's more based on classroom or written application??

I'm not in any manner saying one is better or worse than the other. I'm just saying it causes us to come at this discussion from two different directions. Just as we see the fallacy (sp) of your approach, you see the fallacy of ours.

I will never say any of your lengthy, technical descriptions are "wrong" or "mis-understood" or "not practical" or any of the other descriptive terms Calg and yourself have said about my descriptions. All I ask is the same respect in return.

 

[SPYDERLK]

Sorry. I bolded to draw out the post I was making from those made prior. :confused3:
...I agree that there is a lifting force, but that it is offset by an amount according to the point where load is applied to resist forward motion. I think you will see that consistance in my posts. Perhaps I misunderstand what you mean. Let me ask ... Did you say this? :

Awww Larry,,,, I thought we had covered this already??

If the rear tires do not lose traction and the drivetrain has the power to continue to turn the pinion and the load does not move, the tractor will do a wheelie, "dont matter how low you hitch" That is a true statement and all of the analysis given by yourself and CalG proves it.

... What does it mean?

It means exactly what it says. No loss of traction. Drivetrain with sufficient power to continue to turn. Load does not move. Tractor will do wheelie. Regardless of hitch point.

Your analysis proves that.

In reality we all know that if the hitch point is low enough these truths will not play out because the weight will be lifted off the rear tires and they'll spin.

But if all the circumstances I outlined above are met, the tractor will lift the front end. Everyone in this discussion knows that is true.

I wonder if the differences in this discussion might come from experiences.

I am pretty sure Egon and I base our statements on practical experience of hours in a tractor seat under a wide range of applications.

I'm not so sure what CalG and yourself base your statements on. But it appears it's more based on classroom or written application??

I'm not in any manner saying one is better or worse than the other. I'm just saying it causes us to come at this discussion from two different directions. Just as we see the fallacy (sp) of your approach, you see the fallacy of ours.

I will never say any of your lengthy, technical descriptions are "wrong" or "mis-understood" or "not practical" or any of the other descriptive terms Calg and yourself have said about my descriptions. All I ask is the same respect in return.

Coming from two different directions to get an answer still has to come up with the same answer. Else one or both are not accounting for all factors.

I base my statement regarding tip tendency on physics and buttress it with real world observation. I have yet to disprove physics by real world observation and experience. When I see a discrepancy its because I have missed something. The lever / counter lever approach that is described in post #225 is simple in that it goes to the end effector to avoid confusion in resolving intermediate forces making up the result. Not doing so requires that all intermediate effectors be analyzed one by one ... and only to show that what goes into making the output agrees with the output. It cannot disagree with the output.

The "dueling levers" take everything into account. To duel with the thrust lever, the load lever [resisting applied thrust- aka pull point] must extend below the axle. Both levers, thrust and load, act at the axle. When the load lever is short a hi proportion of torque resisting tip comes from front weight bias. As the load lever is lengthened more and more resistance to tip is produced [a forward torque] and massive front weight becomes less important in real world.-- Nevertheless, in our posited infinite traction and output torque circumstance the front weight would not prevent tip.-- This situation continues until the load lever is lengthened enuf that it places the pull point at ground. ... Now, as usual, all force from the thrust lever is reacted equally against a force on the load lever, but now of the same length, pulling back opposite to thrust. The torques, whether small large or infinite, are always equal and opposite. There wouldnt be a twitch. No change in F/B weight on the wheels. Nothing.
... If you think there is a force unaccounted for it may help to see that the thrust lever [tire radius axle to ground] is just a direct extension of the ring gear.

larry

 

[Egon]

Doing good. Now realize that the pinion gear can keep turning. When that happens a few different factor's come into play.

 

[SPYDERLK]

How can it keep turning against a force that automatically adjusts to equally oppose its turning?

 

[ovrszd]

How can it keep turning against a force that automatically adjusts to equally oppose its turning?

I think we're getting somewhere here if we can all just focus on this point. Our contention is that as long as the powertrain has sufficient power to turn the pinion and the tires maintain traction the light front effect happens. Whether or not the pinion keeps turning has absolutely nothing to do with where the hitch point is, what load it's hitched to, or any other leverages you mention. All of your contentions come into play, but not in regards to the pinion turning and walking around the ring gear. That's a totally separate action and it does not care whether it's hitched to anything or not.

 

[ovrszd]

Maybe this example helps, maybe not.... Looking at Egon's picture of the ring gear and pinion gear. When turning to move the vehicle forward. Where is the greatest load on the pinion bearing closest to the pinion gear??? Top?? Left side?? Right side?? Bottom??

 

[SPYDERLK]

I think we're getting somewhere here if we can all just focus on this point. Our contention is that as long as the powertrain has sufficient power to turn the pinion and the tires maintain traction the light front effect happens. Whether or not the pinion keeps turning has absolutely nothing to do with where the hitch point is, what load it's hitched to, or any other leverages you mention. All of your contentions come into play, but not in regards to the pinion turning and walking around the ring gear. That's a totally separate action and it does not care whether it's hitched to anything or not.

What youre saying is that the pinion can overide a torque generated by its own action, that is equal and opposite to the direction of its action. Why do you say that?

 

[ovrszd]

Larry, I think to start with, just answer my question about the load on the pinion bearing.