L4740 draft control not working

[_RaT_]

For what it is worth, I have tried it with a Kubota L4850, L3830, International 454D and a NH 2120. All were equally effective or ineffective, whichever way you want to look at it. On the other hand, maybe its me...

I've read a handful of other threads here on TBN about using draft control with a box blade for grading.

Maybe the effectiveness of the draft control for grading depends on the tractor...

I would try it out also on my Ferguson TO-30 (one of the first tractors with draft control), but my TO-30's 3-point needs a part that I cannot purchase new... need to find a parted-out Ford 8N or Ferguson TO-30 to fix it.

Jeff

 

[rjkobbeman]

The way I see it, draft control was designed/meant for plowing. A plow has a lot, lot more leverage that a box blade. The draft control kicks in when enough force in exerted on the top link PUSHING against (in) the tractor. (I had a conversation with a friend of mine and he thought the top link pulled to the rear in draft control situations.)

I don't think a box blad had near enough leverage to push hard enough against the top link for the draft control to work.

A plow has a very constant and consistent push against the top link. I would think a box blade would have very small, intermittent pulses (pushes) against the top link which would make it hard for the system to react.

If you buried the scarifiers in the box blade, you might be able to see some draft action.

For the most part though, I think most people use a box blade to level out the ground... not have it buried the same on all contours of the land.

I don't have a box blade, but I do have a big grading scraper. When I finish taking down all of my locust trees in my pasture I may break it out and play with the drafting mechanism a bit. I am interested to see it do something!

 

[Larry Caldwell]

The way I see it, draft control was designed/meant for plowing. A plow has a lot, lot more leverage that a box blade. The draft control kicks in when enough force in exerted on the top link PUSHING against (in) the tractor. (I had a conversation with a friend of mine and he thought the top link pulled to the rear in draft control situations.)

I haven't seen the Kubota draft control, but I have used AC, Ford and Ferguson tractors with draft control, and the sensor on all of them was on the bottom links, not the top link. You set the draft control to the maximum pull the tractor can generate, and when the implement exceeds that pull, the hydraulics lift the implement. I don't see how putting a sensor on the top link would do anything. You don't pull with the top link.

 

[_RaT_]

Super simple really. It does not use the hydraulic top link per se, it simply uses the top linkage as a pivot point. What ever implement you have be it a box blade or plow will exert a load against the top link. That pivot point where the toplink connects to the tractor has a given amount of movement. That movement reacts with a connection that connects to the hydraulics and either picks up on lowers the upper arms which raise or lower the lower links. Easier to go look at it then explain it. The beauty is you can quickly adjust the sensitivity by adjusting the top links connection hole (usually 3 or 4 holes). Any way you look at it though, its never reacting fast enough for grading type work.

I haven't seen the Kubota draft control, but I have used AC, Ford and Ferguson tractors with draft control, and the sensor on all of them was on the bottom links, not the top link. You set the draft control to the maximum pull the tractor can generate, and when the implement exceeds that pull, the hydraulics lift the implement. I don't see how putting a sensor on the top link would do anything. You don't pull with the top link.

 

[rjkobbeman]

Well, last weekend I played around with my draft control. I took out my grading scraper (slightly different from a box scraper... but pretty much the same thing) to flatten out an area that had some big high and low spots.

For this job I lowered the scarifiers. (I normally don't use the scarifiers because I mainly use this scraper to groom a long gravel drive.) I have an 8' scraper with 8 scarifiers. With R4s and fairly hard ground, it didn't take much to start spinning the tires. It was then that I thought of messing with the draft control. First, I moved the top link attachment point on the tractor down to the bottom hole. Second, I moved the position control in the "float" or "all-the-way down" position. I started with the draft all the way down which resulting in tire spin. It didn't take much moving of the draft control lever to see the 3ph start to raise... and then I started moving. Way, way cool.

Talking about a kid with a new toy!

I can see where some may not want to use this because the point is to keep your implement buries as far as possible without tire spin. That may not be the goal in some box blade work. But for me, I wanted to tear up some ground so I could smooth it later with the scarifiers up.

I did not think the scarifiers would have enough resistance to push on the top link enough to register the draft control... but I was wrong. It worked great! Granted, that 8' scraper does produce significant drag.

 

[_RaT_]

Those rippers have intense braking power. The draft control works very well for this type of use.

Well, last weekend I played around with my draft control. I took out my grading scraper (slightly different from a box scraper... but pretty much the same thing) to flatten out an area that had some big high and low spots.

For this job I lowered the scarifiers. (I normally don't use the scarifiers because I mainly use this scraper to groom a long gravel drive.) I have an 8' scraper with 8 scarifiers. With R4s and fairly hard ground, it didn't take much to start spinning the tires. It was then that I thought of messing with the draft control. First, I moved the top link attachment point on the tractor down to the bottom hole. Second, I moved the position control in the "float" or "all-the-way down" position. I started with the draft all the way down which resulting in tire spin. It didn't take much moving of the draft control lever to see the 3ph start to raise... and then I started moving. Way, way cool.

Talking about a kid with a new toy!

I can see where some may not want to use this because the point is to keep your implement buries as far as possible without tire spin. That may not be the goal in some box blade work. But for me, I wanted to tear up some ground so I could smooth it later with the scarifiers up.

I did not think the scarifiers would have enough resistance to push on the top link enough to register the draft control... but I was wrong. It worked great! Granted, that 8' scraper does produce significant drag.