Bent 3pt arm...

[Rowski]

Well another battle scar from snow removal /forums/images/graemlins/frown.gif. Here's a of picture the first one a few years ago. Attached is the damage this year.

I was pushing snow, widening a driveway. Had the rear blade straight, pushing backwards. Caught the outer most edge of the blade on some very hard, frozen like a rock, snow. The tractor stopped and it was spining with chains. I pulled up on the position control level while the tractor was still spining, trying to get better traction by removing the load. Guess what happend next, bent lower 3pt arm /forums/images/graemlins/blush.gif on one side only /forums/images/graemlins/smirk.gif.

It was my fault. I thought that this may happen (someday) but didn't really think to much about it, you know how it is /forums/images/graemlins/crazy.gif. So I have a few questions.

Do you think that the damage to one arm only came because the adjuster for the arm is only able to control pressure of the arm being pulled in. I notice that some tractor have a "slide type" or "deluxe" setup with a pin for adjustment would have helped any? Is it possible to retrofit it with the deluxe style? Has anybody done this? What other sort of things can be done to make this weak link stronger? On the other hand, maybe it good to have a weak link so other more expensive things break?

Thanks for you help!

 

[Rowski]

This is a picture of the right side... Straight like an arrow /forums/images/graemlins/wink.gif

 

[Rowski]

A picture of both sides.

 

[Rowski]

A picture of what I had to get done. Driveway needs to be twice as wide. It is about 500' of this driveway needed to be cleared with about 75' is up against a coral fence and needed to be pushed to the corner (about where the tractor is). I got it done but forgot to take a finished /forums/images/graemlins/crazy.gif picture. Snow was like concrete. Tooth bar helped a lot to loosen it up.

 

[thcri]

Rowski,

That is a tough one. You got a pretty heavy blade and the weak link is the 3pt arm. When you hit something solid like that especially when you have some force going the weak spot has to go. Both links won't bend unless you push them far enough. But I don't have to tell you that. You obviously have a lot more experience than I do. My question out of this whole thing is, is the 3 point actually designed to push? To me that arms are not strong enough to do that. When we pull things the force would be to pull the arms together and a buckling effect is not as prevalent.


Murph

 

[markie61]

sorry your baby got a boo boo... /forums/images/graemlins/frown.gif
I dread the day I do something serious to my "baby blue" - I guess it is almost inevitable.

FYI, you are the 2nd 2120 owner who has pictures of the arms bent. If you do a search on "bent arms" under the NH sections, I think you might find another one with the same issue (if memory serves....)

I can't recall if or how he fixed them....

Mark

 

[JimMc]

Draft links are meant to pull, primarily. Most implements are designed for pulling as well. Even though they may have provisions for being reversed, it is assumed that most of the work will be done while pulling.

Cat 1 tractors have several contributing factors that cause trouble when pushing in reverse, especially with chains added. You see, with chains, a tractor has almost the same traction in reverse as when pulling. The next factor is the design of the Cat 1 system. When pulling forward the geometry of the lift arms tend to pull an implement up and over obstacles. This is the largest limiting element of Cat 1 tractors. Since they have no down hydraulics, the implement weight is the only thing keeping them in contact with the work. When this system is used to push backwards, however, the geometry tends to push down into obstacles, actually transferring some of the weight of the tractor to the implement through the draft arms and (if the implement end of the top link is lower than the tractor end) the top link. Normally, the unidirectional tread of an aggressive ag tire has enough lack of traction that the tractor spins before something gives. When this design is set up with enough horsepower, weight, traction, and a large enough obstacle, you will break things. Sort of like the irresistable force and the unmoveable oject.

With any system, when you increase the capacity of the limiting factor, eventually you exceed the capacity of the system. For instance, Cat 1 tractors modified to include downforce hydraulics will spin out and lose traction next. When the traction problem is solved with weights and dual wheels they break chassis components on a regular basis because it is assumed in their design envelope that the lift arm geometry will allow the implement to ride up and over before forces that break the system arise.

 

[Casimir]

Sounds like the moral is: "It's not good to fool with Mother ( <font color="blue"> Blue </font> / <font color="orange"> Orange </font> / <font color="green"> Green </font> / <font color="red"> Red </font>)." Too much tinkering to increase weight, traction, lift capacity, etc., can cause stresses beyond the design capacity of the machine. /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif

 

[markie61]

The "bent arm" search didnt work. But here is the thread that dealt with it.
Mark

 

[thcri]

Casimir,

But it is exactly like you called it, "A Battle Scar" Hey now you can spend some more money and fix it. That can be just as exciting as driving the tractor itself. Your by your tractor, enjoy it. As I laugh Out Loud

Im not laughing at the money you have to spend. But battle scars do bring back memories.
Murph