Hill Climbing Primer

[SPYDERLK]

You can do it with 2 wrenches of different length trying to turn something opposite one another and prove it to yourself. Different lever lengths is what it comes down to.
larry

 

[Egon]

You can do it with 2 wrenches of different length trying to turn something opposite one another and prove it to yourself. Different lever lengths is what it comes down to.
larry

You forgot the gears and mounted prime mover!

 

[ovrszd]

Note the word " enough ".

Lots of low hitch tractor scenarios will provide enough traction. Lots of times the front of the tractor may be off the ground when starting a heavy load. Tie an 8N to a big tree and have at it.

I grew up on small Ford tractors, 8N included. Dad always said the pulling power of the 8N is unappreciated if the front tires are touching the ground. I was taught and proficiently learned the art of balance using the 3pt lever starting at the age of 7.

 

[Egon]

Yep. The rear axle pinion gear is trying to climb up the front of the rear axle ring gear. Same thing happens in any rear wheel driven vehicle when engine power is applied. That's why Dragsters use wheelie bars even though they have no load hitched to the rear of the car.



http://www.farmsafe.org.au/resources/document/24-10-13_01_36_Safe_Tractor_Operation_Guide.pdf
The last location has information and pictures!:thumbsup:

 

[SPYDERLK]

You forgot the gears and mounted prime mover!

Irrelevant to the result if you set the experimental static situation up correctly.

 

[SPYDERLK]

Yep. The rear axle pinion gear is trying to climb up the front of the rear axle ring gear. Same thing happens in any rear wheel driven vehicle when engine power is applied. That's why Dragsters use wheelie bars even though they have no load hitched to the rear of the car.



http://www.farmsafe.org.au/resources/document/24-10-13_01_36_Safe_Tractor_Operation_Guide.pdf
The last location has information and pictures!:thumbsup:

Compare and contrast highly accelerative conditions with a steady state pull. Weight distribution considerations will receive extra credit.

 

[SPYDERLK]

I grew up on small Ford tractors, 8N included. Dad always said the pulling power of the 8N is unappreciated if the front tires are touching the ground. I was taught and proficiently learned the art of balance using the 3pt lever starting at the age of 7.

Every ounce not supported on a driven wheel is a loss. Approx 1:1 or more with AGs.

 

[SPYDERLK]

I don't think this is right. I have pulled on a stump with my drawbar, and my tractor ground to a halt (wheels spinning), but the front end didn't come up at all.

Just for fun, I made this:

As I said earlier, this is not an accurate repro of what happens in a pull. It is because the driving force is supplied from a reference frame independent of the tractor. Your experimenteffectively has you levering forward on the axle.

You can get an accurate depiction of what really happens by locking those rears and pulling back on the tractor from different heights while touching the tractor in NO other way. Somehow jam the tires against the body or fenders. See if you can get a few pounds directly over or just slightly ahead of the rear axle to assure enuf traction. Height of that weight is not important to a steady state level pull.
larry

 

[ovrszd]

Every ounce not supported on a driven wheel is a loss. Approx 1:1 or more with AGs.

You finally said something I understand. You guys are talking so far above me..... I'm not worthy!!!!

 

[Egon]

Irrelevant to the result if you set the experimental static situation up correctly.

Really? Maybe use a teeter toter as an example. Just change the weight of the Totters. Same as two spaners.

How about a static force diagram?