Hill Climbing Primer

[SPYDERLK]

Look at where your 3pt lift arms are attached to the tractor. They will be attached below the axle center point of rotation. So even if the lift arms are raised to pick up a weight the tractor sees the weight it must pull at this low, below axle, attachment point. This is if you have no top link and you are pulling strictly from the 3pt lift arms with maybe a cross drawbar like this

View attachment 370494

Using the lift arms to pull gives a pulling point below the axle but there is also a rotational force from the weight of the log using the lift arms as levers which will lighten the tractor front end.
This is also true when using the drawbar if there is any tongue weight. >>There is not much difference between using the draw bar or just the lift arms to pull. Both pull from below the axle.<< Both can be dangerous and warrant caution. If you catch the log on a stump. root, or rock and stop the tractor the tires will try to keep turning lifting the front end. This is what makes the tractor pulling hard with an already lightened front end go over backwards so quick. It is the drive to the tires not the load that flips the tractor. Don't assume you are safe because you are using the draw bar. Getting the log off the ground by lifting it with the lift arms requires less pull because it doesn't dig in and you are less likely to catch on something so I think it is better.

If you use a setup that also has a top link connection it gets more complicated. If you are interested look up Harry Ferguson the 3pt hitch inventer to see how his ingenious invention works.

NO! The pull point is from the liftarm endballs. Look at the rigid triangle formed by the tractor chassis, rocker shaft, and lift arms tied by the lift links,. It would not be a matter if you had the arms low, but they would have to be chained downward to prevent them floating up if a backtip started.
larry

 

[joshuabardwell]

NO! The pull point is from the liftarm endballs. Look at the rigid triangle formed by the tractor chassis, rocker shaft, and lift arms tied by the lift links,. It would not be a matter if you had the arms low, but they would have to be chained downward to prevent them floating up if a backtip started.

That's what I think too. If the end-balls are higher than the axle, I believe the effective pull-point will be above the axle and the tractor will want to roll over. This is doubly true if the lift arms are not chained down, and are free to rise up.

It always seemed to me that the safest way to skid a log would be to chain the log to the drawbar with a short chain and then lift the log off the ground separately with the lift arms. That way if the log got hung up, the drawbar chain would take up slack first and prevent any pull on the lift arms. But nobody does it this way, as far as I can tell.

 

[oosik]

Hmmm. My previous tractor that I had for 25 years was exactly what you have. I can tell you from experience - the easiest and SAFEST way to get those logs to the top of the hill is to put one in the bucket and chain 2-3 together and drag them up the hill with a chain or cable attached to the drawbar. DO NOT use the 3-point to pull a load up the hill. Use nothing higher than the drawbar (ex- don't use FEL or 3-point) to pull the load up the hill. The logs could change position(roll) and very quickly you & the tractor could be in a side pull situation and get pulled over and down the hill.

I had a pto winch which allowed me to have 250 feet of 1/4 inch cable. I pulled one log at a time strictly for safety sake. The winch was attached to the 3-point and drawbar. Tight to the drawbar, loose to the 3-point. It pulled on the drawbar and was kept in alignment by the 3-point. It was a Koenig winch.

 

[ovrszd]

Growing up in 2wd tractor World, I've lost count of the number of times I've pulled with the 3pt drawbar and front tires in the air.

 

[SPYDERLK]

That's what I think too. If the end-balls are higher than the axle, I believe the effective pull-point will be above the axle and the tractor will want to roll over. This is doubly true if the lift arms are not chained down, and are free to rise up.

It always seemed to me that the safest way to skid a log would be to chain the log to the drawbar with a short chain and then lift the log off the ground separately with the lift arms. That way if the log got hung up, the drawbar chain would take up slack first and prevent any pull on the lift arms. But nobody does it this way, as far as I can tell.

Yeah. If they are hi they are a problem for backtip, continuing such until the tractor reaches a very hi angle and they become pinned at the top of their travel with balls near the ground ... but rocker shaft/ lift links are having serious issues. -- If lo and not chained they are initially the same as the fixed drawbar because their tractor attachment H is about the same. The killer tho is that, unlike the fixed, the arms can articulate upward at their tractor fastening. During the backtip there is no damping factor at all because the articulation point[and therefore pullpoint] remains at the same H. If the arms could not articulate upward, the balls like the drawbar end would be forced down as a backtip progressed, lowering the pullpoint. This would self limit the tip. You can only get this benefit if you chain them down.

....I like your proposed method of pulling a log. BabyGrand does it like that. Ref thread:

http://www.tractorbynet.com/forums/attachments/177413-how-do-you-hook-your.html#post2022311

 

[Gordon Gould]

That's what I think too. If the end-balls are higher than the axle, I believe the effective pull-point will be above the axle and the tractor will want to roll over. This is doubly true if the lift arms are not chained down, and are free to rise up.

It always seemed to me that the safest way to skid a log would be to chain the log to the drawbar with a short chain and then lift the log off the ground separately with the lift arms. That way if the log got hung up, the drawbar chain would take up slack first and prevent any pull on the lift arms. But nobody does it this way, as far as I can tell.

I guess there is a misunderstanding in what I said. As far as the horizontal force required to pull the log forward goes the rods from the rock shaft to the lift arms hang vertically and can offer no horizontal force to the upper part of the tractor during a pull. The entire horizontal pulling force is taken at the lift arm attachment points below the axle which is essentially the same pull point when using the draw bar. I did say in addition there is a vertical force, the weight of the log, that acts with the lift arms as levers to lighten or lift the front end thus transfering more weight to the rear and offering better traction. I also said this vertical front end lifting force also comes to play when using the draw bar only if there is tongue weight on the draw bar. So I agree with you there is a difference in the two set ups.

If you catch the log and stop the tractor during a pull the horizontal pull force suddendly increases no matter which set up you have. In both cases the front end will try to come up driven by the tires. Now comes the trade-off: If you are pulling from the lift arms with the log off the ground the front end is, as I said, lighter, so it comes up easier but the pulling is also easyer so you have less power to the tires reducing the risk of lifting the front end even though it is lighter. Even if it does come up as soon as the rear end rotates back and the log hits the ground the vertical weight of the log is removed from the tractor and the front end suddenly is no longer light so you get a chance to recover from the tip up. Now, if you are pulling hard dragging the log from the draw bar and the log stops dead, when you start to go up you have more power to the the tires because of the harder drag and there is no sudden increase in front end weight. So, to me, there is less chance to recover from the potential tip over.

Which is better is a matter of opinion. And there are so many possible senarios you can't argue which is best. I prefer the lift arms. Pulling heavy logs is dangerous. You need to understand your equipment and the risks. Think and observe what is happening during the pull. Go slow keep the log low as practicle.

 

[CobyRupert]

Here's the proper way. Hook chains high, overload tractor, minimize front weight, burn clutch. Tractor wheelie - YouTube

 

[SPYDERLK]

I guess there is a misunderstanding in what I said. As far as the horizontal force required to pull the log forward goes the rods from the rock shaft to the lift arms hang vertically and can offer no horizontal force to the upper part of the tractor during a pull. The entire horizontal pulling force is taken at the lift arm attachment points below the axle which is essentially the same pull point when using the draw bar. I did say in addition there is a vertical force, the weight of the log, that acts with the lift arms as levers to lighten or lift the front end thus transfering more weight to the rear and offering better traction. I also said this vertical front end lifting force also comes to play when using the draw bar only if there is tongue weight on the draw bar. So I agree with you there is a difference in the two set ups.

If you catch the log and stop the tractor during a pull the horizontal pull force suddendly increases no matter which set up you have. In both cases the front end will try to come up driven by the tires. Now comes the trade-off: If you are pulling from the lift arms with the log off the ground the front end is, as I said, lighter, so it comes up easier but the pulling is also easyer so you have less power to the tires reducing the risk of lifting the front end even though it is lighter. Even if it does come up as soon as the rear end rotates back and the log hits the ground the vertical weight of the log is removed from the tractor and the front end suddenly is no longer light so you get a chance to recover from the tip up. Now, if you are pulling hard dragging the log from the draw bar and the log stops dead, when you start to go up you have more power to the the tires because of the harder drag and there is no sudden increase in front end weight. So, to me, there is less chance to recover from the potential tip over.

Which is better is a matter of opinion. And there are so many possible senarios you can't argue which is best. I prefer the lift arms. Pulling heavy logs is dangerous. You need to understand your equipment and the risks. Think and observe what is happening during the pull. Go slow keep the log low as practicle.

You are pulling from the H of the ball ends if the hydraulics is holding them above the attachment point of the arms on the tractor for the reason I said earlier. If the ball ends are, instead, lo you are pulling from the arm attach point on the tractor, and since that point will not move downward as the tractor tips the tip does not self damp. The operator has less recovery margin. BabyGrands method has all the advantages you cite as well as the added safety of a drawbar pull.
larry

 

[square1]

Just remember with a locked differential and both wheels spinning the back may go sideways.

Good point about the pitfall of a locked diff. Many touched on this issue, it must be legit.

Are you sure they need to be 16'. That sounds odd to me for hardwood. Or is there a special reason you want them 16 footers ? Just wondering.

I liked the answer I saw on a sawmill forum, "My client wants 16' beams, so I need to cut 16' logs", alas that is not my case. I wanted to present the worst case for input. I'll cut them shorter if I need to, but you never know unless you ask.

Another day night & day of rain is giving allowing more time to think this over / read responses. Have to admit, what started as "feeling" there was more to it than throw a chain around the log and drive up the hill has been substantiated by all of your comments. Thanks for all the ideas and warnings. Talking it out is the best way to get the best plan.

 

[joshuabardwell]

If you catch the log and stop the tractor during a pull the horizontal pull force suddendly increases no matter which set up you have. In both cases the front end will try to come up driven by the tires.

I may be misunderstanding your example, in which case I apologize, but I don't think this is correct. If you are pulling from below the axle, then the torque will tend to rotate the front end downwards into the ground. If you are pulling from dead-center on the axle, there will be no torque. And if you are pulling from above the axle, the torque will tend to rotate the front end upwards.

I think what you are saying is that the lift arms attach above the axle, so if you are pulling from the lift arms, there will always be torque to raise the front end--but to me that seems like an argument for pulling from the drawbar, not the lift arms.