will this damage? hitch ball to drawbar

masscity · Dec 26, 2005

When I was a kid/teen we had 240 acre farm and we always did logging on the side for extra money. We had a Case Vac14. The only way you could skid the logs out of the woods was hooking to the 3pt hitch and raising the front end and putting weight on the rear wheels for traction. It scared me when I was young, but it never tipped over backwards and I quickly got used to it. Also it's very easy to control the height of the front end by lowering the 3pt hitch. I have a 1978 Kubota B7100 bought new by me. Currently be used by my brother for mowing. Around 1980 we had a bad windstorm in the Detroit area and a lot of trees came down. I got a lot of free firewood for my fireplace. I was pulling 20-30ft long up to 18"butt logs up wet, greasy clay hill with my little B7100. Hooked to my 3pt hitch. Tried keeping my 3pt hitch low and using my 4wd and it would just spin. Raised my 3pt hitch and put all the weight on my rear wheels like we did with our Case and away she went. I'm not recommending that anybody do this, it's up to you, but I've never came close to tipping over. Everybodies pucker factor is different. This only my opinion and I don't want to offend anybody.

Trev · Dec 26, 2005

( This is getting silly. First semester engineering question.

If the line of the chain and hitch are below the axle (viewed taut from the side), it should not flip the tractor.

Russell in Texas

)

I feel a bit silly for asking this, thinking the answer is probably self-evident to anyone with even a whit of engineering knowledge, but that kind of rules me out. /forums/images/graemlins/blush.gif

Let's say you are pulling with the 3pt hitch, but you lower that hitch so that it's only, say, six inches off the ground, or however low you have to go to be beneath the level of the rear axle. Now you are pulling from a low point, much as you would be with your drawbar. But, the only place the actual force on the tractor will be is at the mounting points of your 3pt lift arms, which would be a couple or three feet above the ground.

How is the tractor going to respond in this situation? As if it were hooked low, or as if it were hooked high? I know it seems silly, but I can't get my mind wrapped around this one. /forums/images/graemlins/wink.gif

I'm trying to picture it happening, but both scenarios seem equally plausible in my diminutive brain.

Maybe what we need are some of those multi-million dollar flight simulator training machines, re-programmed to let prospective tractor-owners get some safe seat time!

I can just hear Farrah Fawcett's voice calmly telling me "I'm sorry, you just flipped your tractor and are now dead. Would you like to try this again?" /forums/images/graemlins/grin.gif

Bob

Steve_Miller · Dec 26, 2005

Bird has given you the best advice. There is always the possibility of flipping as you are not always on flat terrain. As the tractor goes up and down so does the angles at which you are pulling from. Just always beware of what is going on and what you are driving over.

Steve

rdsaustintx · Dec 26, 2005

( How is the tractor going to respond in this situation? As if it were hooked low, or as if it were hooked high? I know it seems silly, but I can't get my mind wrapped around this one. /forums/images/graemlins/wink.gif )

I think it should still not flip. What makes this analysis so easy is chain - It can only transmit tension in a line, so drawing a free body diagram is easy. If the line of the chain is below the axle, the resulting moment pushes the front down.

Even if there is a higher intermediate structure (the 3ph in your example), taking the moment about the frame pins shows it is also pushing the front down.

Ain't physics fun? /forums/images/graemlins/confused.gif /forums/images/graemlins/laugh.gif

There are obviously a lot of log-draggers here and I have the benefit of no actual experience /forums/images/graemlins/cool.gif But I would use the drawbar and clevis, hitch line slightly under rear axle. I would also load my FEL. That way if I was wrong it would save family the expense of a burial. /forums/images/graemlins/shocked.gif

Speaking of funerals, all this talk about snapping chains is really scary.

Bird, I would never argue with you. If you say you're not always right I have to agree. Because you're always right.

My head hurts. /forums/images/graemlins/crazy.gif

Trev · Dec 26, 2005

( I think it should still not flip. What makes this analysis so easy is chain - It can only transmit tension in a line, so drawing a free body diagram is easy. If the line of the chain is below the axle, the resulting moment pushes the front down.

Even if there is a higher intermediate structure (the 3ph in your example), taking the moment about the frame pins shows it is also pushing the front down.)

Gotcha! If you really do think it out, it becomes obvious doesn't it?

( There are obviously a lot of log-draggers here and I have the benefit of no actual experience /forums/images/graemlins/cool.gif But I would use the drawbar and clevis, hitch line slightly under rear axle. I would also load my FEL. That way if I was wrong it would save family the expense of a burial. /forums/images/graemlins/shocked.gif)

If you do flip over, the load in the FEL automatically buries you! I like the way you think!

( Bird, I would never argue with you. If you say you're not always right I have to agree. Because you're always right.

My head hurts. /forums/images/graemlins/crazy.gif)

Yeah, there's one of those logic traps it's so easy to fall into. /forums/images/graemlins/grin.gif

My favorite is "This statement is false." Hmm. If it's false then it's true, but if it's true then it's false. /forums/images/graemlins/grin.gif

Thanks.. you cleared up my thinking on this....

Bob /forums/images/graemlins/grin.gif /forums/images/graemlins/smile.gif

Steve02 · Dec 26, 2005

What would be really nice, IMO, is a drawbar that would release itself from the tractor if the angle of the tractor (or drawbar) changed past a certain point.

So to even put your drawbar in the reciever slot it would have to held up at (or past) this release angle.

Then it wouldn't matter how fast you were to the clutch (or how fast you were moving, within reason) because as soon as the front of the tractor came up off the ground and the critical angle reached, the drawbar would release itself and the front of the tractor would come back down.

geish · Dec 26, 2005

Well, my setup worked fine. Somtimes, the chain would slide off the logs, but it didn't happen but one or two times.

I'll post pics when I get he pics developed. I need to scan them in. Digi. cam. would be nice. I need to get mine fixed.

Thanks for all yall's help.

btolle · Dec 26, 2005

( Well, my setup worked fine. Somtimes, the chain would slide off the logs, but it didn't happen but one or two times. )

I bought a 3/8"log chain at Tractor Supply for about $25 that I use. It has a slip hook on one end so it will tighten itself on the log. I 'think' it was a grade 70 transport chain so it is pretty heavy duty. Like the one at http://www.lacledechain.com/hardware/log.html

Harbor Freight sells one also but Tractor Supply was cheaper.

Bill Tolle

Toolguy · Dec 26, 2005

I like how this post has finally come full circle with geish answering his own question. It is a great example of common sense in action. His method of moving logs works and that is the bottom line. All the talk about flipping tractors and breaking chains has been very valuable from a safety point of view. However, it did not answer his question as to whether it would damage his tractor to pull from a hitch ball attached to the drawbar. The answer is obvious. Of course not. The drawbar is designed to be pulled from. The only question worth discussing is what is the best way to hook a chain to the drawbar. I say that is a matter of personal choice. I have a hitch ball on my drawbar to pull a trailer. I often wrap the grabhook end of a chain around it and use the sliphhook end to pull trees or branches. I also have a clevis that I attach to the 3PH drawbar. For the biggest logs that I attempt to pull I will also use the 3PH to lift the end off the ground and put the extra weight of the log on the rear wheels for more traction. It also keeps the end of the log from digging into the ground and catching on roots or stumps. I might flip the tractor over while pulling that way but, airplanes crash, ships sink, lightning strikes and meteorites fall out of the sky and kill people, too. I'll take my chances. As for breaking chains, you WILL break your CUT before you break a 3/8" chain. They are tough, even the cheap ones. As long as you don't jerk on them even a good 1/4" chain on a steady pull will take anything you can give it with a CUT. I grew up on on a large farm where we had a Cat 'dozer that Dad used to clear fencerows, dig out stumps, bury rockpiles and just about anything you could think to do with a 'dozer including plowing and tillage work. I learned at an early age about chains and pulling with tractors. I often helped by dragging anything I could pull with the Ford tractors that we had after Dad dug it out with the Cat. I was only 10 years old when I started doing it by myself and it was just about the most fun I have ever had in my life. He taught me the three rules to live by that I have never forgotten. Hook a chain ONLY to the drawbar or 3PH drawbar, DON'T jerk the chain and go SLOW. I am still here 44 years later and those rules still apply today.

This post has been a lot of fun to follow. Every reply was helpful in some way. I hope mine is too and as always it is just my .02 anyway so please take it as that.

rk246 · Dec 28, 2005

I like the clevis hitch on the drawbar, with a grab hook on that end of the chain, then a slip hook on the other end of the chain to come tight on the log when I am pulling it. Never had the front end come up at all...