What size of plow sweeps do I need?

kebo · Aug 16, 2015

I'm in the process of restoring an old cultivator and I need to get some new sweeps to go on it. This one has 6 shanks on it, and I need 3 new ones. One of them broke off, a couple are smaller than the others, and the other three are sort of a mismatch. I realize they sometimes run different sizes of sweeps on the same cultivator, but I want to go back with all six pretty close as I can get, without buying a new set of six.

What I would like to know is how do you measure them? I looked at the Agrisupply site and found one that looks to be close to what I need, take a look and see what you think.10 X 1/4 Cultivator Sweep

Here's two of them.

jeff9366 · Aug 16, 2015

I use a Woodward Crossing's S-tine Cultivator with six tines and 9" sweeps, the widest sweeps available for S-tines. If you use sweeps too wide, the draft force can bend the flexible S-tines back irreversibly, or draft force will stop the tractor.

In my sandy-loam soil I pull the Cultivator in HST/MED with some throttle. I have been surprised the draft force is equal to pulling a 16/18" Disc Harrow with gangs set fairly aggressively. My tractor has 35-hp and weighs 5,400 pounds.

My friend Carl Cornwell pulls the same Woodward Crossing's S-tine Cultivator outfitted with five tines and 7" sweeps. Carl has a Kubota BX2230, ( Photo #3) 4-WD, 22-hp and around same weight as your Deere/Yanmar 790, which I presume has 4-WD.

So I think around 35" of total sweep width would be about right for your JD 790, divided between your six tines, perhaps 6 X 6"? Unless your soil is clay, I feel confident with this recommendation.

You want some space between the sweeps so they do not clog with pulled out weeds. Also, leave a little slack in your Lower Link stabilizers so entire cultivator moves around a little and so sweeps can slide around subsurface obstructions.

Newly installed sweeps work loose quickly. Check them frequently and tighten nuts on bolts until the assembly settles in. Buy a few extra of the nuts and bolts you need and one spare sweep.

bdog · Aug 17, 2015

They are measured at the widest point width wise on the tips of the wings. They aren't that expensive I would replace them all. I recently put 21 on my plow. You want them wide enough that they overlap each other by a little bit or weeds will slip through. My plow has three rows of them so there is a decent space between them on each row so they don't plug up. Mine are either 16 or 18".

bdog · Aug 17, 2015

Wanted to add that my plow is a chisel plow with heavy shanks. If yours is more of a cultivator with light shanks you can't use sweeps that big. Most cultivators have 6-8" sweeps.

kebo · Aug 17, 2015

bdog said:
Wanted to add that my plow is a chisel plow with heavy shanks. If yours is more of a cultivator with light shanks you can't use sweeps that big. Most cultivators have 6-8" sweeps.

This cultivator has six pretty heavy shanks on it, they do not flex nor do they have springs on them so they can "trip" over roots, etc. I measured the three good sweeps on it, they are all different. They measure 8", 9" and the largest is 10". I think I will get three 8" sweeps. If I were going to keep this attachment, I would get go ahead and get 6 new ones, but I'm planning to flip it after I get it painted and put it all back together with some new bolts. Thanks for the info.

/pine · Aug 17, 2015

JMO...but for that money I would spring for a complete new set...!

I keep experimenting with a few odd sweeps I have on my hiller/bedder...

sixdogs · Aug 18, 2015

Most sweeps are 5" or 7" and there are different degrees of the shank. 43 and 47 degrees are the most common. You might have a mix of both so try to find one that looks like it's flat to the ground and look for a number on the back.

You can pull a wider point but not very deep. These are intended to go only a couple of inches deep in ground that has already been worked. If you go deeper you will need more HP and stronger shanks. For example, I have a 16 shank homemade cultivator that uses IH vibrashanks and it takes around 75 HP and 4WD to pull it 5" deep. It's a heavy framed unit that I often have 2" wide points on. With a lighter cultivator--Dearborn 7 1/2' wide and eleven 5" points, I only need 40 HP and 4WD to go a couple inches deep in softer ground.

This is the heavy one

This is the lighter one

Mace Canute · Aug 19, 2015

sixdogs said:
Most sweeps are 5" or 7" and there are different degrees of the shank. 43 and 47 degrees are the most common. You might have a mix of both so try to find one that looks like it's flat to the ground and look for a number on the back.........

kebo, this is a very important point and one you have to pay attention to if you want to ensure your shovels or sweeps run flat on the bottom.

kebo · Aug 20, 2015

Mace Canute said:
kebo, this is a very important point and one you have to pay attention to if you want to ensure your shovels or sweeps run flat on the bottom.

I don't think the angle of the sweeps is that critical on this cultivator. The shanks have a fitting on the end that actually allows you to adjust the angle of each sweep. I can also adjust the height (or depth) of each sweep relative to each other, by raising or lowering each one independently. They can also be angled in or outward (like a toe in or toe out). Heck, I could even turn them around 180 deg and use the cultivator in reverse gear!!

Not sure you would want to do that though!

HAPPYNC · Aug 20, 2015

sixdogs said:
Most sweeps are 5" or 7" and there are different degrees of the shank. 43 and 47 degrees are the most common. You might have a mix of both so try to find one that looks like it's flat to the ground and look for a number on the back.

You can pull a wider point but not very deep. These are intended to go only a couple of inches deep in ground that has already been worked. If you go deeper you will need more HP and stronger shanks. For example, I have a 16 shank homemade cultivator that uses IH vibrashanks and it takes around 75 HP and 4WD to pull it 5" deep. It's a heavy framed unit that I often have 2" wide points on. With a lighter cultivator--Dearborn 7 1/2' wide and eleven 5" points, I only need 40 HP and 4WD to go a couple inches deep in softer ground.

View attachment 438179

This is the heavy one

View attachment 438180

This is the lighter one