Skidding hitch

[Andy1969]

From an engineering standpoint the top link must be in tension. Otherwise you couldn’t pick anything up. The only time a top link goes into compression is when something goes wrong such as not having it adjusted properly and brush hogging in hilly terrain. That’s why the better brush hogs have attachments designed to pivot to allow for that so your top link doesn’t see compression and buckle like a wet noodle. I don’t plan to go crazy with this hitch. But the idea of hooks up high is to hitch, lift the three point, and get thtbut end out of the dirt so it skids easier and safer. I’ll let you know how it goes next week if it dries out.

 

[wagne223]

Depending on the implement, the top link experiences both compression and extension forces.

When carrying an implement or ballast it is extension, when pulling a ground engaging implement the top link is under compression.

And of course sometimes it is both depending on the job.

The lower link arms are designed to do the pulling and therefore are the strongest.

The top link job is to hold the implement angle of attack.

One thing is certain, the top link is not as strong as the lower arms.

To the OP.....that is a fine job on that skidder! As already mentioned though, I would only use the upper ring's for lifting a log over an obstacle and only slow and easy.
For the actual skidding I would put a hook in that lower receiver and drag away.

 

[bcp]

You could put a short chain and grab hook in or by the receiver.

Lift the log. Back up a bit so the chain is near vertical. Hook the short lower chain to the first chain. Drive away, pulling from the bottom of the hitch.

Bruce

 

[majorwager]

An analogy can be drawn to 3 point BH's and why subframe mounts are crucial on compacts especially. Dragging the log on the toplink, similar to closing BH dipper arm.

I have a 10 ft BH that will rip the toplink completely off most ulitily and compact tractors.

When something disastrous occurs, comforting to reflect back upon warning advice received in advance from TBN members.

Tension and compression discussion irrelevant at that point.

 

[Andy1969]

Sure. But saying a 3 point backhoe exerts the same amount of force on a tractor as skidding some tops doesn’t really seem reasonable. I have skidded similar sized stuff with my Kawasaki Mule and I’m pretty sure I could pull the Mule in half with the tractor without damaging the tractor. I’ve got a lot of big rocks sticking up in my woods and if you don’t get things lifted up over them they will snag on them and that’s when things get interesting in a bad way. This setup will only exert as much force on things as the tractor generates and that is ultimately controlled by me. Slow and steady is the rule for me. If I try it out and decide a couple hooks lower down would be good, then I’ll add them. That’s the fun of building your own stuff. You can try it and tweak it till you have it just right

 

[LouNY]

You could put a short chain and grab hook in or by the receiver.

Lift the log. Back up a bit so the chain is near vertical. Hook the short lower chain to the first chain. Drive away, pulling from the bottom of the hitch.

Bruce

That would be the best way, it's getting the but out of the dirt and adding weight to the rear of the tractor while pulling from the lower links.

 

[Stomper]

Or just a simple chain from the logs to the draw bar. That way the only force the top link should see is the weight of the lifted log and the pulling force is from down low at the draw bar. I see no reason why what you made shouldn't work.
BTW Nice fab work. Looks great

 

[Stomper]

Depending on the implement, the top link experiences both compression and extension forces.

When carrying an implement or ballast it is extension, when pulling a ground engaging implement the top link is under compression.

And of course sometimes it is both depending on the job.

The lower link arms are designed to do the pulling and therefore are the strongest.

The top link job is to hold the implement angle of attack.

One thing is certain, the top link is not as strong as the lower arms.

To the OP.....that is a fine job on that skidder! As already mentioned though, I would only use the upper ring's for lifting a log over an obstacle and only slow and easy.
For the actual skidding I would put a hook in that lower receiver and drag away.

I am in no way an expert on this subject but I agree with the above statement 100%

 

[rScotty]

From an engineering standpoint the top link must be in tension. Otherwise you couldn’t pick anything up. The only time a top link goes into compression is when something goes wrong such as not having it adjusted properly and brush hogging in hilly terrain. That’s why the better brush hogs have attachments designed to pivot to allow for that so your top link doesn’t see compression and buckle like a wet noodle. I don’t plan to go crazy with this hitch. But the idea of hooks up high is to hitch, lift the three point, and get thtbut end out of the dirt so it skids easier and safer. I’ll let you know how it goes next week if it dries out.

I'd be careful with that hitch when you first use it.
It is more common to have the hooks down low so that the lower lift arms do the lifting of the log. With the hooks high like that you are un-necessarily raising the Center of Gravity relative to the tractor.

On 3pt geometry, the outer end of the top link is typically shorter than the lower arms and also only slightly above horizontal when the implement is raised for carrying. If the top link is so long that the outer end of the top link can sweep a radius larger than the angle swept by the outer ends of the lift arms then the hitch will tilt out instead of in when lifted.
I'd shorten the top link and lower the attachment point by about a foot.

It doesn't help much to refer to a bush hog mower geometry for 3 pt design. B Hogs have a screwy parallelogram type of 3 pt attachment designed to keep the brush hog level for mowing. Instead, take a look at the 3pt hitch geometry of something that is used to pull hard and control heavy weight down low - like a box blade.
BTW, those are nice welds. I shouldn't won't hurt your hitch to put another mounting point for the top link and some lower hooks on it.
luck,
rScotty

 

[Andy1969]

Thanks for all the feedback. I attached a photo of a hitch available from Northern that I based mine on. I read all of the reviews on it and all were positive. The exact geometry might not be identical but you蛟､l see it too has the hooks up on top. At any rate I蛟､l give it a go this weekend and let you know what I find out. If using it shows mods are needed that逞ｴ no big deal. I like the idea of adding a second attachment point for the 3 point down a little lower. Thanks again for the feedback. That痴 the fun of building your own stuff and sharing it!