[bentonkb]

I've got a homebuilt garden tractor that uses a modified Sears 3 pt hitch. It works OK with the plow, but not great. Some of the problem is side-to-side sway, which is mostly fixed with chains.

The tricky problem is depth control - I'd like to get it to run at 4.0" to 4.5" deep, but it cuts about 1/2" deeper on each pass until the differential is dragging on the ground. I know I could add a gauge wheel, but I've read that a properly set up plow should not need one and will pull with less draft without one.

Here's what I'm thinking (tell me if I'm on the right track) -- to make the plow dive down the point has to be lower than the heel but when the share is at the correct depth the point and heel need to be at the same height. To get that action, the plow pitch has to change as the 3 point hitch moves up and down. If the 3 pt top link is parallel to the hitch then the pitch will be constant and will keep trying to dive.

I fooled around the hitch geometry and figured out that to make the plow pitch change from point-down to level as it dives one of two things must be true: either the top link has to be shorter than the hitch arms or the gap between the top link and arms has to be smaller at the front end.

Is that true? Do you experienced plow hands know if the hitch geometry is a important factor?

 

[Robert Webb]

IF you set it up according to the manual on a HARD surface using the blocks under the tires on the left side of the tractor does the plow sit FLAT on the surface or is the rear of the landslide off of the ground? It should be sitting flat on the ground.

BUT.......I dont understand how you can keep getting it cut deeper without changing the way it is set up.....that part confuses me.

Here is the manual for the plow that I am using...........just in case you dont already have it.............Interesting reading also

http://brinly.com/manuals/Brinly-Products/BH-Ground-Engaging/PP-1200BH_PP-51BH/L-1044-1_PP-1200.pdf

 

[bentonkb]

Robert -- I did adjust the toplink to level the plow like you said, but don't you need the plow to be pitched point-down when it is in the higher position just before it hits the ground?
What makes the pitch change as it moves up and down? I think the important factors are the top-link length and its angle relative to the lower hitch arms. When I mounted this hitch to my tractor I did it in the most convenient way without thinking about those two important factors and now I'm regretting it.

 

[SonnyT]

3 pt doesn't raise and keep the implement parallel to the ground. It swepts up with the point of the plow pointing more toward the ground when raised.
Similar to a SH hitch arch, but not as drastic of a angle. You need to set it as at the right angle when in the furrow, like Robert said, and the point should touch first when lowering into the ground and then leveling when reaching the depth you want. :trink40:

 

[bentonkb]

Sonny -- Thanks. That's the picture I need. See how the top link is shorter than the lower arms? It also looks like the gap between the top link and the lower arms is bigger on the back (plow) end and smaller on the front (tractor) end. If I understand correctly, those are the two things that make the pitch change as the hitch moves up and down. I'm trying to figure out what the right amount is -- doesn't that seem important?

I made a model of the hitch and found that if you make the top link longer than the lower arms and/or attach the top link to a point high up on the tractor then you get the opposite kind of pitch change. If you do it that way the point-down pitch gets steeper as the plow dives deeper. Seems like it would be totally unstable that way.

Can you get your plow to run at a constant depth without using the gauge wheel or using up-lift on the hitch hydraulics?

 

[Robert Webb]

If you set it up to plow at 6" according to the manual........when you drop that plow it will dig in until reaches the depth of 6".......then it is going to be LEVEL and will not want to dig any deeper nor will it want to raise up.......