What is draft control

[npalen]

That's depth and/or position control, not draft control. All draft control does is control the draft (pull) on the tractor. It does not control depth.

This is why it's important for everyone to speak the same terminology and why draft control seems to be a confusing mystery to a lot of people.

I'm assuming that, when the back wheels of the tractor go thru a ditch that the plow would ten to dive, right? So that would put a compression load on the top link so the draft control would raise the plow, right? That's not position control, right?

Draft control controls the draft by controlling the depth in various conditions.

Edit: The video posted above shows the ditch scenario very well starting at 2:25 on the timeline comparing depth control to draft control.

 

[MossRoad]

Harry Ferguson invented the three point hitch because people were getting killed when the tractor rolled over backwards while trying to plow. After some attempts he on a handshake agreement allowed Henry Ford to use it. The 9N, 2N, 9N. Harry wanted to use the hitch but Ford refused to stop. Harry sued Ford. Ford lost and had to use a different system for their hitch. Ferguson started US production of the TO20 later to be the TO30, later the TO35 then Massey bought Ferguson and it became 35. FYI Ferguson tractors TO= Tractor Overseas, TE=Tractor England Remember Ferguson was Irish.
What was unique about Ferguson's three point was it used position & draft control by controlling input to a scotch yoke pump.
Draft control some refer to as automatic depth control. On Ferguson's tractor the top link with a ground engaging implement pushes toward the tractor as the implement tries to rotate around the lower hitch bar. this force operates internal linkage to raise or lower the implement by the amount of force of the top link. The benefit of this is as the implement pulls harder and the hitch attempts to raise the implement it also adds weight to the tractors rear wheels.
Later tractors and other makes have used lower link sensing. The amount of pull from the lower links is used instead of using a top link. This became necessary especially for semi mounted plows.
A good draft system will be very sensitive to minor changes in the load. A poor draft system can be very frustrating.
WARNING Do NOT use DRAFT control to attach or detach implements. Usually they either moves full up or full down and can move unexpectedly. Use only POSITION control when attaching or detaching implements. Position control should move only according to movement of the control lever

I was just watching this video earlier tonight.

 

[MossRoad]

I'm assuming that, when the back wheels of the tractor go thru a ditch that the plow would ten to dive, right? So that would put a compression load on the top link so the draft control would raise the plow, right? That's not position control, right?

Draft control controls the draft by controlling the depth in various conditions.

"Draft control controls the draft by controlling the depth in various conditions."

Draft control controls the draft by varying the depth in various conditions.

Controlling depth keeps it the same everywhere.(position control)
Varying depth increases or decreases the load on the tractor.(draft control)

This explains it better than I can.
From here:

hydraulic system position and draft control

hydraulic system position and draft control

www.kf-international.com

•Position control :This will control the working depth of 3-point hitch mounted implement regardless of the amount of pull required.

•Draft control: This will control the pull of the 3-point implement. As the load on the 3-point hitch changes due to various soil conditions, the draft control system automatically responds to these changes by either raising or lowering the implement slightly to maintain a constant pull. Place the position control lever in the lowest position and set the implement pull with the draft control lever.

•Mixed control: In draft control, when draft decreases, the implement automatically lowers to increase draft. However, the implement sometimes lowers too much. To limit the degree, the implement can be lowered, set the position control lever at the lowest working depth desired for the implement. Lower the draft control lever to the

point where the implement is at the desired depth. This stops the implement from

going too deep and causing loss of traction and ground speed.

•Float control: Place both the draft control lever and the position control lever in the float position to make the lower links move freely along with the ground conditions.

 

[npalen]

I was just watching this video earlier tonight.

The video beautifully shows, at about 4:10, the increase in weight on the front wheels. Otherwise the video is quite ambiguous about controlling depth and never mentioning draft control, unless I missed it

 

[npalen]

"Draft control controls the draft by controlling the depth in various conditions."

Draft control controls the draft by varying the depth in various conditions.

Controlling depth keeps it the same everywhere.(position control)
Varying depth increases or decreases the load on the tractor.(draft control)

This explains it better than I can.
From here:

hydraulic system position and draft control

hydraulic system position and draft control

www.kf-international.com

•Position control :This will control the working depth of 3-point hitch mounted implement regardless of the amount of pull required.

•Draft control: This will control the pull of the 3-point implement. As the load on the 3-point hitch changes due to various soil conditions, the draft control system automatically responds to these changes by either raising or lowering the implement slightly to maintain a constant pull. Place the position control lever in the lowest position and set the implement pull with the draft control lever.

•Mixed control: In draft control, when draft decreases, the implement automatically lowers to increase draft. However, the implement sometimes lowers too much. To limit the degree, the implement can be lowered, set the position control lever at the lowest working depth desired for the implement. Lower the draft control lever to the

point where the implement is at the desired depth. This stops the implement from

going too deep and causing loss of traction and ground speed.

•Float control: Place both the draft control lever and the position control lever in the float position to make the lower links move freely along with the ground conditions.

I totally agree with all of the above!

 

[MossRoad]

The video beautifully shows, at about 4:10, the increase in weight on the front wheels. Otherwise the video is quite ambiguous about controlling depth and never mentioning draft control, unless I missed it

It was not talking about draft control. It was talking about position. His system was designed to keep the implement in the same position all the time.

 

[MossRoad]

I totally agree with all of the above!

YAY!

 

[npalen]

YAY!

Its all about semantics.

 

[MossRoad]

Its all about semantics.

I worked an I.T. help desk for a couple decades. "My computer isn't working" Well, is it your computer, or your monitor, or your keyboard, or your mouse, or your operating system, or your program, or your network, or you, etc.?

 

[npalen]

I worked an I.T. help desk for a couple decades. "My computer isn't working" Well, is it your computer, or your monitor, or your keyboard, or your mouse, or your operating system, or your program, or your network, or you, etc.?

I think that the word "control" is what causes ambiguity and disagreement in the draft control discussions. I think of "control" as either holding at a set depth as with the depth control lever or changing depth on the go to satisfy the draft control requirement.

Others may think of control as in the depth control lever on the 3PH system where it limits the maximum depth of the implement. It "controls" the depth.

I've probably just created more ambiguity.