Draft Control / Position Control

[HobbleCreek]

Here I go again showing my ignorance --what is the difference between Draft Control and position control, and when do you use each?

I have read that the Kubota 5030 has draft control available, while the Deere 4000 Twenty series has only position control. Anybody know if this is correct? For what tasks would I miss having the draft control?

-- Grant

 

[HobbleCreek]

. . . and now, demonstrating my impatience . . . I just did a Google search and found this explanation of 3 point hitches, including position control, draft control and response control. Maybe somebody else will find it useful, as I did.

http://www.tractorsmart.com/main/Tractor%20Three%20Point%20Lift%20Types.htm

Regarding the draft control issue on the 4x20 series tractors, the shield that covers the position control lever has a slot for a draft control lever. It seems kinda odd that it would have that slot but not have the control available even as an option.

-- Grant

 

[timb]

Deere *had* draft control available as an option on the 4000 and 4000-Ten series large frame tractors, it was dropped as an option when the Twenties came out. The upper cover to the diff/hitch rockshaft area changed part #'s at the same time - so I assume that the draft control bits are incompatible with the new cover. I emailed but never got an explanation from Deere why they did this. There does not appear to be any 'improvement' made otherwise to the 3-point hitch that forced the loss of the draft control as a compromise, so it was one area that was *not* "new and improved" for the Twenties.

 

[redlevel]

In my opinion lack of draft control is one of the major failings of the CUT tractors. It is almost impossible to plow without it. How can you truly call it a "utility" tractor if you can't plow with it? I realize that most buyers of these tractors will probably never use a ground engaging implement, but some of us still farm. That's why I still love my Ford 640 and my MF 135.

 

[bam747]

I totally agree that loosing draft control on the 4720 (or other CUTs and Sub-CUTs) is a loss in functionality that can be useful for ground engaging implements. However, I'm also assuming that most CUT buyers will probably not use a lot of primary tillage implements (plows, rippers, etc). Rather, they will primarily be used for things like box blades, rear blades, rotary tillers, etc. In other words, things that would not benefit by the use of classic draft control on the 3PH

Although the 4x20 series has lost draft control, I might propose that the LoadMatch feature built into the eHydro transmission can provide an alternative solution to the draft control issue for ground engaging implements.

Consider that draft control is designed to maintain a uniform draft load on the tractor's engine by varying the depth of draft on an implement as the ground conditions change. This means it will lift the implement slightly as it encounters a high draft condition to lessen the load on the engine. It will also return the implement to its original depth as the draft load decreases. One disadvantage of this situation is that you actually end up with a non-uniform tillage depth in order maintain a constant load on the tractor.

Now consider the function of LoadMatch in combination with the eHydro transmission. Instead of raising and lowering a ground engaging implement to maintain a constant load on the engine, LoadMatch will constantly adjust the effective gear ratio of the HST transmission to maintain a constant load on the engine while leaving the ground engaging implement at a constant depth.

LoadMatch also has the advantage of working with non ground engaging implements like rotary mowers when you encounter heavy mowing conditions. It will automatically slow down the tractor's ground speed for the rough spot and then speed it back up when you move out of the tough mowing condition.

If you look at Deere's and other manufactures current large Ag tractors, you'll find that they offer the new Infinitely Variable or Constantly Variable (IVT, CVT) transmissions as well as some form of auto shifting transmissions that all do their best to keep a constant load on the tractor's engine by varying the transmissions gear ratio. Of course, on these larger Ag tractors intended for primary tillage, they also all offer some kind of draft control as well.

So, although I do wish Deere still offered draft control as a option on the 4x20 tractors, it would appear that the standard LoadMatch on the eHydro HST transmission could be a valid substitute for the majority of draft, and other, loads that might be realistically used on a CUT.

JMHO...

 

[HobbleCreek]

</font><font color="blue" class="small">( JMHO... )</font>

In this case, the H stands for "helpful"

Thanks,

-- Grant

 

[timb]

Interesting concept, although there are some cases (moldboard plows for example) where ground speed is intrinsic to the implements action and effectiveness. It could be better to reduce depth (ala traditional draft control) than ground speed per Loadmatch.

Obviously Deere felt that the call for draft control on a CUT was rare and not a useful option to keep on the books. However, it isn't like they needed to *add* it, they actually had to take action (changing top cover design) to make it *unavailable*. Unfathomable.

 

[5030]

I'll throw a stick on the fire and state I prefer "mixed" control of tillage implements.

 

[Toolguy]

Draft contol was invented by Harry Ferguson as a way to pull a plow without needing to have a heavy tractor. The old Fergusons and Fords were pretty light tractors and the theory was that the weight would transfer from the plow to the tractor and give it the needed traction to pull the plow. Under ideal conditions the plow would want to go deeper into the soil until the tractor could no longer pull it. As the plow went deeper it would want to roll up. This was prevented by the top link on the 3pth. As the force from the top link pushed on the tractor it would accuate a valve that would lift the lower arms until the plow was up enough to take the tension off of the top link. At that point the lift arms would stop raising and maintain a preselected depth. This would also increase the weight on the rear tires which would prevent them fom slipping. This idea was in contrast to other plow manufacturers that made pull type trailer plows. These plows were very good at maintaining an even depth across a field. They relied on a heavy tractor that had the necessary traction to pull them in all conditions. This added to the cost of the tractor and plow and gave the Fergusons and Fords a price advantage. It worked fairly well and a lot of farmers used that setup. It was new idea at the time though as farming had just come out of the Horse drawn era where size and weight were everything. Both methods of plowing worked and farmers may still argue to this day as to which one was best. I think the usefulness of Draft Control is overstated. I grew up driving the old Ford tractors and did a lot of plowing with an 850 with a 3X14 mounted plow. We never used the draft control at all as it is too difficult to maintain an even plowing depth. If the ground is soft the plow goes too deep, if the ground is hard it lifts and plows too shallow. Our fields were all a mixture of sand, loam and hard clay. The low spots were sandy and soft so the plow would go too deep. The normal spots were loam and in those conditions the draft control would work OK but, as soon as you went up over a hill it would be hard clay and the plow would go from 7" to 3 or 4. The best way to maintain an even depth across the field was to always have your hand on the position control lever and adjust the depth as necessary as the field conditions changed. It is really not that hard to do and it makes the job of plowing for hours and hours and not falling asleep at the wheel a little easier to do. We also had a 3020 John Deere in the late '60s with 4-16's semi-mounted and did the same thing with that. It had draft control as well (load sensitive on the lower links only) but we never used that either. If you got into hard plowing conditions you did not want the plow to raise up. You wanted it to stay at the desired depth so it was sometimes necessary to shift down a gear and keep going. Likewise, in sandy conditions you could shift up and really get some plowing done although you had to be careful of hitting rocks. Even with trip bottoms it could be quite hard on the plow if you went too fast. However in the old days, most farmers loaded their tractors to the max and speed was not usually a problem. Nowadays, everything has so much more power. I am sure draft control has it's purpose but, I am not sure what it is, either. I want anything I pull to hold it's depth and not raise or lower just because the ground is a little harder or softer in spots. The newer John Deere Load Match adjusts the speed and torque to match the conditions without changing the position of the implement. That seems more useful to me than draft control but you can always manually adjust your speed also. Heck, if you make it too easy it takes all the fun out tractor driving. /forums/images/graemlins/grin.gif

 

[ALABAMA_KID]

whew!!! /forums/images/graemlins/tongue.gif

That is the same way we plow around here..
Never know what kind of dirt you will be in next.