adjusting offset disc

[Pav]

I have a Ford 8N with an offset disc that I am using to turn over my ground to plant permanent pasture. I notice that the disc drags to the left when discing. Also, it is very difficult to turn to the left when discing (much more easier to the right) - is this the general rule for offset discs? Is there some sort of adjustment that I can make to the disc travel smoother and perform better? Also, when discing, should the tractor be in draft control (position control lever down)?

Thx,
Pav

 

[oldnslo]

1) Is the disc cutting evenly side to side? From what you are describing it sounds like the right side may be cutting deeper which would push the rear of the tractor left.

2) Is the disc level front to back? If one gang is cutting deeper than the other it will also tend to push the tractor around.

Roy

 

[gwdixon]

I have a Ford 8N with an offset disc that I am using to turn over my ground to plant permanent pasture. I notice that the disc drags to the left when discing. Also, it is very difficult to turn to the left when discing (much more easier to the right) - is this the general rule for offset discs? Is there some sort of adjustment that I can make to the disc travel smoother and perform better? Also, when discing, should the tractor be in draft control (position control lever down)?

Thx,
Pav

Is it a drag type or a 3PH type offset disc? It makes a difference how the tractor reacts.

Draft control should have no effect on a drag disc. On a 3PH offset disc you would not use draft control.

If you look at the discs, they are made to turn to the right (or in the direction of the bottom of the "V" made by the gangs. If you have a 3PH offset it will turn the tractor to the right when it really sinks in.

Don't turn to the left. It gouges the soil and may even break a blade. It also puts excessive stress on the bearings and mounting hardware. Plan out your route to always turn to the right.

If you get in a corner, open up the adjustment bar, back up until the blades are parallel, lock the adjustment, and drive to where you can always turn right.

What you are experiencing is how offset discs react. Just allow for it.

 

[Pav]

Still a little confused. It is a 3PH offset disc, with the bottom of the "V" formed by the gangs pointed to the left (most of the pictures I see are configured this way). Based on the reply, it sounds like it should therefore turn better to the left, but it does not, much less resistance to the right. I also read in another forum that offset disks are made to be pulled counterclockwise (to left). I adjusted the disc to raise up the front gang some (which is pointed to the left) and it seemed to help with the disc dragging in that direction and helped turning left. Maybe I need to raise the front even more, leaving most of the tilling to the rear gang which points right. Also, why shouldn't I use draft control with an offset disk? Thanks.

 

[Pav]

Here are some pictures (sorry, I took them at night):

 

[gwdixon]

OK, photos help.

"oldnslo" has a hint on his post above (2nd bullet). The fronts blades seem quite a bit more worn than the rears thus they are smaller and bite less. Maybe it is perspective in the photo.

The scalloped, or weed-cutter, blades in front also will dig slightly less. Lifting the front of the disc, as you did, with a 3PH will cause the rear gang to dominate, catch the dirt, and pull the rear to the right. The front of the tractor will likely be pushed to the left. Do you notice a slight offset of the tractor as you travel straight?

When you turn left the rear gangs increase their bite (as if opening the disc even more aggressively) and they plow rather than cut. The fronts decrease their bite and just roll along like very skinny tires.

Turning right will do just the opposite but the front gang is closer to the rear of the tractor and thus has less leverage.

Based on what you have posted, my advice would be to lower the fronts (shorten the top link) to make the disc cut the same front and rear (like oldnslo notes). Because of the increased resistance in the front as the front gang digs in the rear gang may slightly raise or tilt especially if you have a spring loaded draft control top link. This is fine and will make the left turn easier. Just don't engage the draft control to raise the disc.

Draft control will reduce your discing efficiency. Unless the tractor is losing traction or the disc hubs are burying in the soil, draft control will work the ground at different depths. It is better used for subsoiling, plowing, or with a box blade/rear blade where there is a possibility of damage to the tractor or implement. It also can regulate depth/load so some folks like it for smoothing gravel or dirt with a blade. I think of discing more as "deep-mowing" so leave the draft control off to get an even cut.

One advantage of a 3PH disc is that it can be lifted at the end of a pass, a quicker turn made, and a clean pass made the other way. You may have to finish the ends of the field with additional passes but that is better than having soil piled up unevenly in the turning area.

You are correct about the counterclockwise path for most offset discs.