Mundane operating questions for 6.5 foot disc

[Z-Michigan]

Well after two plus months of debating, we finally bought a disc harrow today. The one I selected is the "Farm Force" 6.5 foot "heavy duty" model, see:
American Farmland - Heavy-Duty 6’ Disc 18” Blades - By Tarter Gate

This is now sold at the local TSC stores. Weight is rated as 846lbs and the discs are 18", with notched front and smooth rears.

I've never used a disc before today. I ran it around my to-be hayfield for about half an hour, and found that it was smoothing the soil and preparing a seedbed somewhat, but only with multiple passes. So, I have some fairly mundane operating questions:

1) The disc came with both gangs set in the shallowest angle (discs almost perpendicular to direction of travel). I am finding that the disc is slicing but only very slightly disturbing the soil. I assume I should angle both gangs more?

2) Related note: while discing in fairly dry soil that has been chiseled, I am getting only 2 to 3" of penetration. That doesn't seem like much, especially since this disc is relatively heavy for the class. Any suggestions on getting more penetration, other than adding weight? If I do want to add weight, what are good methods and how much weight is likely to be ok?

3) Most mundane of all - the gang angles are held in place by large bolts instead of by the handy pull pins I could have had on a disc costing $500 more. I have tried to loosen the nuts with a 15" wrench and haven't budged them. The disc hasn't been sitting too long and there's no outward sign of corrosion on the fasteners. Any suggestions besides a cheater bar? I have read about something called a torque multiplier - is this an actual tool that will increase the torque of a wrench? Where would I get one?

4) How critical is my toplink adjustment? I tried using the disc level and tried it with the toplink shortened, resulting in the rear gang barely skimming the ground. Surprisingly, with most weight on the front gang, I seemed to be getting less penetration rather than more, and less smoothing. So I went back to the original setting and oddly the rear gang seems to be doing more of the work. I'm wondering if I passed through and beyond a sweet spot where both gangs would work, but the total adjustment of the toplink was barely over an inch. Is this a really critical setting?

 

[Limecuda]

My Howse disc is very similar. I had to use a cheater bar (drill stem) to break the bolts loose in order to move the angles. I also angled mine more towards the rear. It cuts the ground and makes a nice row.

 

[Soundguy]

3" is pretty average penetration on soil that has not been heavilly worked.

Remember.. many people use a plow.. then disc it.

You can make the disc cut more by angling the disc gangs more...

You can add weight to make it cut more..

soundguy

 

[Farmwithjunk]

Well after two plus months of debating, we finally bought a disc harrow today. The one I selected is the "Farm Force" 6.5 foot "heavy duty" model, see:
American Farmland - Heavy-Duty 6’ Disc 18” Blades - By Tarter Gate

This is now sold at the local TSC stores. Weight is rated as 846lbs and the discs are 18", with notched front and smooth rears.

I've never used a disc before today. I ran it around my to-be hayfield for about half an hour, and found that it was smoothing the soil and preparing a seedbed somewhat, but only with multiple passes. So, I have some fairly mundane operating questions:

1) The disc came with both gangs set in the shallowest angle (discs almost perpendicular to direction of travel). I am finding that the disc is slicing but only very slightly disturbing the soil. I assume I should angle both gangs more?

2) Related note: while discing in fairly dry soil that has been chiseled, I am getting only 2 to 3" of penetration. That doesn't seem like much, especially since this disc is relatively heavy for the class. Any suggestions on getting more penetration, other than adding weight? If I do want to add weight, what are good methods and how much weight is likely to be ok?

3) Most mundane of all - the gang angles are held in place by large bolts instead of by the handy pull pins I could have had on a disc costing $500 more. I have tried to loosen the nuts with a 15" wrench and haven't budged them. The disc hasn't been sitting too long and there's no outward sign of corrosion on the fasteners. Any suggestions besides a cheater bar? I have read about something called a torque multiplier - is this an actual tool that will increase the torque of a wrench? Where would I get one?

4) How critical is my toplink adjustment? I tried using the disc level and tried it with the toplink shortened, resulting in the rear gang barely skimming the ground. Surprisingly, with most weight on the front gang, I seemed to be getting less penetration rather than more, and less smoothing. So I went back to the original setting and oddly the rear gang seems to be doing more of the work. I'm wondering if I passed through and beyond a sweet spot where both gangs would work, but the total adjustment of the toplink was barely over an inch. Is this a really critical setting?

In most cases I've seen, the gang adjustments will allow for "not enough angle", "enough angle" and "too much angle". Try somewhere in the middle for starters. Front gang should be adjusted one notch MORE aggressive than the rear. Too much rear gang angle will "ridge" or throw dirt into a pile in between the rear gangs, leaving you with a very irregular finish. Too much (too aggressive) angle will cause the blades to resist rolling, dragging them instead of them rolling along like they should. They'll ride up out of the ground rather than dig in hard conditions.

Toplink adjustment can help. Shortening the top link weights the front gang which does the lions share of the digging. Rear gang SHOULD be leveling what you've cut up with the front. Keep in mind that when you have a good bit of front gang angle AND the top link is shortened a great deal, you'll be weighting to outer ends of the front gangs and raising the middle portion up out of the ground because of the "chevron" shape. When all is well, you want the disc gangs to be cutting nearly equally, front to rear, favoring the front SLIGHTLY if anything.

If you're in chiseled ground and only getting 2" to 3" of penetration, you need MORE WEIGHT most likely. In chiseled soil, normally you'll have to use the 3-point hitch to gauge the disc from dropping in too deep. It wouldn't be out of the ordinary to see a disc running to the hubs in chiseled ground. Anything heavy that can be mounted in a safe manner will do the trick. (i.e. Railroad rail, wheel weights, concrete, ect....) Add the weights to the front of the disc frame so the tractors lift has an easier go of it. I see 5 blades per gang, 20 altogether. That computes to around 41 lbs per blade. About average for a medium duty disc of that nature. That's enough for some jobs, but for good penetration in tough conditions, 50lbs per blade is marginal at best.

Also, what ground speed are you operating at? The faster you go, the more soil action, but the more a disc will tend to ride up out of the ground. 4-1/2 to 5 mph is just about right in most cases.

The bolts.... Do you have access to an impact wrench? Other than that, try a penetrating oil of your choice, then a breaker bar. If your breaker bar is up to the task, try a pipe "cheater" on that. I've seen dozens of discs where thse bolts were replaced with hitch pins. Once you go that route, most likely your threads will get bunged up, so make certain that's what you want to end up with before trying that approach.

 

[Z-Michigan]

Thanks, all. I had forgotten to ask about best operating speed but I needed that info also. I guess I'll be experimenting today, looking for a breaker bar (or borrowing an impact wrench) and see what I can do.

 

[GreenMtns]

I looked at a torque multiplier wrench at one point but I could buy some good implements for what one of those costs.

Al

 

[andrewj]

harrow is not primary tillage. you must chisel plow or bottom plow first. Once ground is worked up, you may harrow for 2 or three years, but then must renovate.

 

[Z-Michigan]

Just wanted to let everyone know that I got the disc working to my satisfaction today. We used my longest wrench (15") and a wooden mallet to pound on the end of the wrench until the nuts came loose. From there the adjustments were straightforward. I liked the disc with the front in the 2nd most aggressive setting and rear in 3rd; my wife preferred the tillage action with the front at 1st most aggressive and rear at 2nd. We've half disced up the field we wanted to. Once that's done, I'm going to switch back to my preferred settings since they give a much smoother finish, and tighten the nuts down within my strength level (not the 300 ft-lbs that the factory must have used).

The difference with more angle is amazing. With the shallowest angles it did very little. Now it's mixing and turning over pretty well. We are getting maybe 4-5" of penetration. Again, this is on ground that was chiseled (actually scarified, but the effect is almost the same) a few weeks ago. I think our clay loam soil may be a factor in the limited penetration. I definitely wouldn't want the disc to be any lighter!

We are getting a center ridge but I think this is unavoidable. We didn't see an option for a center sweep on this model.

FWIW, I am finding best performance, with these aggressive angles, at just 3 to 3.5mph. Soil type may be a factor. I have the hp to pull faster, but my wife was watching closely and said faster causes it to skip and not work as well. The disc is using a fair bit of hp, though I am still running in 2wd mode and using only 1/3 of full throttle.

 

[Farmwithjunk]

Another adjustment that was skipped over will lessen that center ridging. On just about every disc I've ever ran across, you can set the rear gangs farther apart (or closer together) The outer-most rear blades should sit out past the front gangs by roughly the width of the individual disc spacing. (Width of spools) An inch or so MORE won't hurt a thing. A couple inches wider spacing in between rear gangs will reduce that center ridge considerably.

Shorten up the top link a turn will also lessen the center ridging.

 

[texasjohn]

You are on the right track... experiment with the adjustments as you have been, observe the results. You have asked all the right questions and discussed all the various adjustments available. The adjustments needed will change as your soil, moisture, and amount of trash change. I'd use 4wd if you have it. I have a similar disk and piled rocks on it until I can bury the disks to the axle.... speed and results are also a result of depth of penetration and prior condition of the soil. Final trick... you can disk in one direction, then come back at about a 60 degree angle... the second pass at this angle REALLY churns up the soil.