Couple ? about 3pt hyd

[Mickey_Fx]

I'm still trying to figure out how the draft control on this tractor works. Got part of it figured out but still have a couple questions.

Do you know what this control is? (see pic) It's almost hidden by the seat and as can be seen it's next to the draft and lift levers. When moved forward and near the end of it's movement, it places a load on the tractor. Suspect it has something to do with the hyd but not sure exactly what.

Have got the draft linkage connected to my quick hitch frame and now draft control will raise and lower the 3pt lift. The draft sense control lever next to the top link runs forward to a shaft on the side of the trans. On the same shaft (mounted coaxially) is another control link that goes to the uper lift arm. What this link controls I don't know.

Reading over again in the manual (Murray Publishing) there is not a lot of info on the working of the 3pt lift but it does sound like there should be down pressure on the lift except when position level is all the way forward. Manual also says draft control will raise the lift when implement is placing too much load on the lift. With implement mounted solidly to 3pt I don't see how the draft control via the sense lever can see this load.

So anyone know what the control in the pic is for and if you should see down pressure on the lift arms except for full forward position?

 

[Tom_Veatch]

So anyone know what the control in the pic is for and if you should see down pressure on the lift arms except for full forward position?

Can't help with the control/thumbscrew, but as I understand it, the 3pt position lever positions the 3pt lift arms at a particular height (angular position) and holds them at that location. However, when the position lever is fully forward, the arms are put in "float" mode with no hydraulic pressure applied in either direction and allows the attachment to follow the grade or ground level.

I'm with you as far as understanding the "draft" (as "force") control. With the setup on my tractor, I can't see how it senses force. Position, yes. Force, no.

Now, if the position lever was in "float" mode and the "draft" control was set up and connected properly, I can see where it (draft control) could control the depth of a plow or some other ground-engaging attachment. If the plow tried to dive too deep, the position change could be sensed and pressure applied to lift and correct the position. But that is strictly a position sensing activity and without some sort of load cell, I don't see how it can sense the amount of "pull".

 

[Mickey_Fx]

Looks like I forgot to mention in the original post. On the tractor there is no down pressure. No matter where the lift lever is placed I can lift the arms, i.e. it floats. Was hoping the control with the thumbscrew would have something to do with locking the arm in set position but it doesn't. Don't know what/if there are any problems with the lift. Was hoping if someone could tell me if their machine locked the lift arms via the position lift lever.

 

[Soundguy]

Almost all 3pt hitches with no downpressures are of a free floating dogbone/cam design.. Units with downpressure will be different.

Soundguy

 

[Tom_Veatch]

Wouldn't a system without the capablilty to apply downpressure somewhat reduce the utility of a "draft" control?

My reasoning: I've read in several posts that the purpose of the draft control is to maintain a constant pull force on the attachment. In order to do so, the system would have to be able to lift the implement to reduce ground resistance if hard or difficult conditions increases the load. Likewise the system would have to force the implement deeper to increase ground resistance when soft or easy soil conditions reduces the load.

It's just my uninformed, inexperienced, and half-baked opinion, but I would think that a constant "draft" (in the sense of depth as the "draft" of a ship's hull in water) would be preferable to a constant "draft" (in the sense of pull as in a "draft" horse).

Even if constant depth were the goal, it seems that a lack of down pressure would be still be a serious fault in the system. There would be no ability for the system to counteract any tendency of the implement to broach the surface.

 

[Ductape]

I'll post a pic of the draft control on my YM, since its more exposed than the control of your FX. I'm just going to give my educated guess on this. Your draft control will only regulate the height of the hitch (and therefore, depth of the implement). I don't see how it will add pressure to an implement, just adjust the height, or depth of the implement. However.... many implements by design, will dig deeper, or harder the further in the ground they are. I suspect this is where the confusion is.... with certain implements, the "pressure", or amount the implement "wants to dig in", will be controlled by the depth of the implement in the soil.

I suspect your draft control on your FX works in the same way as a YM. There is a rod with two spring loaded stops on it which control where the upper and lower limits of the TPH are. These stops are adjustable, so you can set the depth of your implement in relation to your tractor. When your implement gets to its given depth or height (set by the stops) it keeps the TPH from dropping or raising farther by closing (or opening) the hydraulic valve that controls the TPH.

I'm not sure i've worded this in a way thats easy to understand..... but perhaps seeing an exposed draft control will help you understand how the adjustable stop works on your tractor, as the mechanics of yours may be hidden by your tractors bodywork.

 

[Soundguy]

Down pressure unweights a tractors rear end.. thus reducing traction.. that's not a good thing during tillage.

'Ground vacume' -sucks- the tillage instrument.. like amoldboard plow into the ground.. the draft works against that.. adjust the draft sensitivity so that if it pops out of the ground, the hyds let it plunge to correct deptch again. The plow will naturally suck into the ground due to cutting angle.

Soundguy

Wouldn't a system without the capablilty to apply downpressure somewhat reduce the utility of a "draft" control?

My reasoning: I've read in several posts that the purpose of the draft control is to maintain a constant pull force on the attachment. In order to do so, the system would have to be able to lift the implement to reduce ground resistance if hard or difficult conditions increases the load. Likewise the system would have to force the implement deeper to increase ground resistance when soft or easy soil conditions reduces the load.

It's just my uninformed, inexperienced, and half-baked opinion, but I would think that a constant "draft" (in the sense of depth as the "draft" of a ship's hull in water) would be preferable to a constant "draft" (in the sense of pull as in a "draft" horse).

Even if constant depth were the goal, it seems that a lack of down pressure would be still be a serious fault in the system. There would be no ability for the system to counteract any tendency of the implement to broach the surface.

 

[Mickey_Fx]

Ductape, our tractors are very different in how the draft control operates.

In this thread I've used the word "sense" when talking about the draft linkage but I don't know if in fact it is to sense the load other than what I read in the manual the the draft control senses the load and controls the implement depth. Who ever wrote the English manual, do they actually know or are they drawing on convientional knowledge?

In the attached pic you can see the bailing wire conncetion I made to the implement. With the connection made the draft control lever will raise and lower the 3pt arms but I don't see any way it can sense the load. Presently I don't see the draft control doing any more than can be done by the position control lever. The draft control will set the lower limit on the arms but that can be done with the stop on the position control lever. Without this bailing wire connection I've temp made, the draft control lever does nothing.

In the pic you can see the linkage that is connected to the lift arm and forward to the same "rod" going into the side of the trans as the draft sense linkage is.

As I'm composing this a thought has come to mind. I wonder if the control I first wrote about (one with thumbscrew) could be some sort of pressure limit control for the lift arm load. If load exceeded the setting, the arm starts to drop, the draft linkage see the movement of the arm and applies pressure to raise the arms. As I previously mentioned when this control is moved forward it applies a load on the engine. Humm?

Wish I had a plow and a piece of ground that was in need of turning so I could try this out. Oh, for the lack of a tool.

Soundguy, not to be critical but I don't see where either of your 2 posts have added anything to the discussion. The question is NOT how draft controls in general work but how they work on these models. If you know how they work on THIS tractor, please comment.

 

[Soundguy]

Ahh... I see that you do not read each message completely.

Here is the pertinant line I was replying to in Tom_Veatch's message when i mentioned that items like plows suck into the ground on their own.. and do not have to be 'forced' into the ground as Tom_Veatch was thinking.

>Likewise the system would have to force the implement deeper to increase >ground resistance when soft or easy soil conditions reduces the load.

Also.. my first line about downpressure unweighting a tractor's rear end, thus reducing traction was in reference to this line from Tom_Veatch's message.

>Wouldn't a system without the capablilty to apply downpressure somewhat >reduce the utility of a "draft" control?

Draft adjustment, traction, and implement adjust all work together, and are all needed in specific ratio..

I disagree that the conversation is only about how draft control works on these models, vs how draft control works in general. Tom's message made that pretty clear.. his questions were general 'draft' questions.. not yanmar machine specific. ... 6 of my tractors have draft control.. i've used plenty of tillage equipment including moldboard plows, and rebuilt draft sensing hydraulic systems...

However.. since I'm -obviously- not adding anything.. ...I'll go ahead and bow out of this thread.

Soundguy

Soundguy, not to be critical but I don't see where either of your 2 posts have added anything to the discussion. The question is NOT how draft controls in general work but how they work on these models. If you know how they work on THIS tractor, please comment.

 

[Mickey_Fx]

Was over to tractor Ernies this PM and we spent a fair amount of time on draft controls on the Yanmars. Ernies doesn't know exaclty how the draft control operates other than when it is all connected to a tiller with UFO controls.

He had no idea what the control I asked about initially but was aware when moved forward it loaded down the engine.

Since he has several F series parts tractors we spent some time looking them over. Wish I had taken the camera along as the trans was fully exposed. Now for the control I was asking about. It operates some kind of valve assy that is attached to the right side of the housing that contains the knob for down flow control. Don't know it's intended purpose.

Ernie has several xx03 tillers with all the bells and whistles on them. He pointed out he was sure the linkage I've been refering to connects to some linkage on the tiller and attaches to the rear drags. Giving this some thought I could see how the position of the drag flaps could indicate depth of the tiller. Will have to give this some further thought and possible take another look at Ernie's tiller with the linkage on it as a straight connection would cause the draft control linkage to move in the opposite direction necessary.

Maybe in the end what I'll find out is the draft control only functions with the correct tiller and nothing else. But I'm still going to pursue finding out how this all works. Wish the draft control was more convientional in operation then Soundguys comments would be more helpful to all.

Hope there are a few others here that are interested in how the draft control works on their tractor. If not I'm wasting everyone time with this quest I have. I did note that on the newer models, the Fxxx there is no draft control but the UFO control has much more capabilities built in like electrical switch that flips to either raise or lower the tiller to a set point. Pivot of the tiller tines and L/R tilt. The UFO controls are mounted where the draft control is on my model.