Learn me about draft control

[Tx Jim]

Here's a video I found that very informative concerning draft control & moldboard plows.

 

[av8tr72]

So how and where do I set the levers?

 

[Gator6x4]

No it don't keep the plow from going deeper. Draft keeps the tractor from going deeper.

??????? Scratch head.

Mossroad explained the tractor going deeper in post# 10.

 

[ROUSTABOUT]

??????? Scratch head.

Mossroad explained the tractor going deeper in post# 10.

Show me a draft that lets a plow down below your initial lift handle setting. I can show you several that let the plow up above your initial lift handle setting. So, if it let's the plow up, it reduces drag on tractor, keeping wheels of the tractor from Spinning down. It's reverse thinking, but that's why it is still a novel idea since its invention.

 

[Tx Jim]

JD lower draft link sensing such that my JD 4255 & other JD tractors built from 1961-1992 can allow plow to go a little deeper briefly than initially set in softer, sandier soils.

 

[npalen]

In this situation draft control when set properly will lift the plow when the tractor is getting more pull "draft" to maintain the engine load in tough going as the load "draft" decreases it will lower the plow to the previously set level. It will not lower it lower then the initial set level.
What this actually accomplishes is plowing less depth in hard ground and the desired depth in easier going.

Draft control is designed to maintain a more constant load on a tractor by varying the depth of a pulled 3 point mounted implement, normally a plow. It do so by lifting the plow from it's set depth to a shallower depth as the load increases and lower it as the load decreases untill the set depth is achieved. It will not lower the implement lower then the original set depth.

Lou, I understand the idea of draft control as accomplished via sensing tractive load. I would have loved having draft control back in the '50's (Yes, I was a kid in those days. ) when moldboard plowing with our CAT RD6, D2 and IH WD9 tractors. The problem would have been the plow only cutting half as deep in the hard clay gumbo and then dropping down to full set depth in only the sandy loam. Would have been great in that the tractor wouldn't require shifting down as much except when going up a hill it would probably still have required a downshift.

I doubt that Dad, however, would have approved of the plow constantly changing depth as the idea was to maintain a consistent depth. I feel reasonably sure that draft control was invented by Harry Ferguson in an attempt to overcome the lack of weight and traction of the little Ferguson.

Just some personal thoughts here and not directed to anyone or anything in particular.

 

[npalen]

Here’s how it worked on my IH2500b. That used a rock shaft to detect load. Other machines use different methods. But the goal is the same: if the tractor load starts to increase, draft control raises the plow (or whatever implement) out of the ground to decrease the load. As the load returns to normal, the draft control lowers the plow further into the soil, up to the depth that your position control was set to, and no deeper.

How draft control works, as explained on my old IH2500b...

There's a triangle formed by three sides:

1- the line of the back of your tractor
2- the line of your lift arms to implement
3- the line of your top link

There's a rock shaft somewhere at the point that your top link connects to your tractor.

Now, let's say you're driving along with a plow in the dirt. You're in soft easy soil, and all of a sudden you come into some harder soil. Your plow has a harder time cutting through the soil, putting drag on the tractor, so the rear wheels start spinning instead of pulling forward.

As the rear wheels spin, they start digging a hole, which lowers the rear of the tractor.

When the rear of the tractor lowers, the implement does not, because it floats.

Since the rear goes down and the implement does not, that puts pressure on your top link. The top link is trying to get shorter but it's solid. It has to maintain the three legs of the triangle. The implement pushes the top link against the rock shaft. The rock shaft activates the 3 point hitch to lift the implement out of the ground. It keeps lifting until the plow comes out of the ground enough to allow the rear tractor tires to stop digging a hole and start moving forward enough to allow the pressure on the rock shaft to diminish and it lowers the plow back into the ground, eventually back to the pre-determined depth that your position control was set at, unless it hits hard dirt again.

The plow causes a constant push and relax on the top link, depending on soil conditions.

You can manually set the sensitivity of the draft control to react faster or slower to conditions.

So, to summarize:

Draft control keeps your tractor from burying the rear tires by raising and lowering the implement as soil conditions change.

Position control allows the implement to drop to a preset depth and no more.

"When the rear of the tractor lowers, the implement does not, because it floats."

So what keeps the implement from going deeper? In other words, what causes to to "float"?

 

[LouNY]

Lou, I understand the idea of draft control as accomplished via sensing tractive load. I would have loved having draft control back in the '50's (Yes, I was a kid in those days. ) when moldboard plowing with our CAT RD6, D2 and IH WD9 tractors. The problem would have been the plow only cutting half as deep in the hard clay gumbo and then dropping down to full set depth in only the sandy loam. Would have been great in that the tractor wouldn't require shifting down as much except when going up a hill it would probably still have required a downshift.

I doubt that Dad, however, would have approved of the plow constantly changing depth as the idea was to maintain a consistent depth. I feel reasonably sure that draft control was invented by Harry Ferguson in an attempt to overcome the lack of weight and traction of the little Ferguson.

Just some personal thoughts here and not directed to anyone or anything in particular.

I agree my father wanted a certain depth period no deeper and no shallower, and don't get stuck in that mud hole.

 

[LouNY]

I just bought a Case 105A upgraded from a Kubota that did not have this. In the operators manual it mentioned 2 settings. One is where you push the position lever all the way forward and set the implement depth with the draft control lever. The other is where you set the position of the implement with the position lever and then you move the draft control lever to match the position lever. Basically seems like you get the same results ? It does not say much else.
I will be pulling a 3 point plow and I am wondering what is the difference between the two settings?
I understand that the basic function of draft control is to keep the plow from digging deeper while plowing but I’m not sure how to set the levers for when I am using the plow with draft control.

Rereading this I'm beginning to wonder if both the settings you describe are two different draft settings.
The first sounds almost like it would be a total draft control allowing your implement your implement to adjust up and down to maintain a constant draft, I've never seen one like that, but who knows with these newer tractors.
Your second setup sounds more like what I would expect with an implement that could use draft control and not try to be a submarine..
I've run many tractors that have draft control on them but I have not even tried to use it since the 60's. And now days we don't even have a moldboard plow on the farm, it's either no till or tow behind chisel plows. So no way to even try one of the newer tractors with it.

 

[av8tr72]

Rereading this I'm beginning to wonder if both the settings you describe are two different draft settings.
The first sounds almost like it would be a total draft control allowing your implement your implement to adjust up and down to maintain a constant draft, I've never seen one like that, but who knows with these newer tractors.
Your second setup sounds more like what I would expect with an implement that could use draft control and not try to be a submarine..
I've run many tractors that have draft control on them but I have not even tried to use it since the 60's. And now days we don't even have a moldboard plow on the farm, it's either no till or tow behind chisel plows. So no way to even try one of the newer tractors with it.

So basically the first one will find whatever depth it likes. As far down as it will go and up to where the draft control lever is set. It will just dig at whatever depth to not bog the tractor down (basically)
The second will be set to a depth with the position lever, say I wanted 4 inches deep. It will ride between 4 inches and raise its self to adjust for heavier soil.
Guess that makes sense.