ID an old 7 ft disc?

   / ID an old 7 ft disc? #1  

JRobyn

Elite Member
Joined
Dec 4, 2003
Messages
2,794
Location
Middle TN
Tractor
Kubota L4330HST
Hi guys. I've been needing a heavy disc, known around here as a "bog disc" to try to level out about 2-3 acres of my back field. This one came up on auction locally and looks like it might fit the bill. Especially if I chain down about 1,000 lbs of tree trunk on top.

Anyone recognize the maker? Any opinions about the sturdiness of it's construction? I'm not too sure about the "serpentine" frame. What do I need to check about it's condition other than the disc and bearing/axle condition?

187-7.jpg
 
   / ID an old 7 ft disc? #2  
Hi guys. I've been needing a heavy disc, known around here as a "bog disc" to try to level out about 2-3 acres of my back field. This one came up on auction locally and looks like it might fit the bill. Especially if I chain down about 1,000 lbs of tree trunk on top.

Anyone recognize the maker? Any opinions about the sturdiness of it's construction? I'm not too sure about the "serpentine" frame. What do I need to check about it's condition other than the disc and bearing/axle condition?
View attachment 484761

Keep looking, waaaaay to small and light duty. If you put 1000lbs on top, I venture to say that you will have scrap metal in a very short amount of time.

Keep in mind that light duty implements are not intended to be heavy duty implements and are not structurally built to handle such tasks.

If you need a 1500lb-2000-lb set of disks, that is what you need to buy or rent.

Also remember, with bigger tractors, bigger implements are typically also needed. They sort of go hand n hand.

Good luck
 
   / ID an old 7 ft disc? #3  
I concur with Brian.

Disc Harrows are secondary tillage implements, originally designed to follow a plow, smoothing plow furrows.

As tractors have grown from 25-horsepower in the late 1930s, when tractor drawn, Three Point Hitch mounted Disc Harrows were designed, some Disc Harrows have become heavy enough to accomplish primary tillage. This category includes Offset Discs and Tandem Disc Harrows with 24" diameter pans.

Assuming you have 4-WD, your L4330/HST can pull a Box Frame Tandem Disc Harrow with 20" diameter pans in HST/MED and 4/5 throttle, through previously broken ground. This is not really heavy enough to provide primary tillage. You will likely have to use another implement to make the initial soil cuts. A plow would be ideal. Improvisations include a Subsoiler or Middle-Buster. For your three acres you could also use a PTO powered roto-tiller if the soil is soft and you have time. Georgia red-clay is tough.

To improve cutting ability of a Disc Harrow, shorten the Top Link. This lifts the rear, smoothing gang; shifting weight to the forward cutting gang.

http://www.tractorbynet.com/forums/attachments/308251-disc-harrow-selection-18-45-a.html?highlight=

Bog Discs, a small category, "normally" have only the front 'cutting' gang of pans, the rear 'smoothing' gang is omitted.
 
Last edited:
   / ID an old 7 ft disc? #4  
What they said.
 
   / ID an old 7 ft disc?
  • Thread Starter
#5  
Thanks for the educated/experienced advice. I'll pass on this one.

My "project" is a field that was evidently rough-plowed years ago and then left before ever being drug or disced. It is now hardened and very rough as in 6"-8" ruts, dips and peaks. I think I could drag it with a box blade or LPGS, but will need something to CUT the surface vegetation first (grass and various thoroughly rooted weeds). Hence a heavy disc. I don't mind going slow in 4wd, HST Low range, and using ALL 43 (or about 40 wheel) HP.
 
   / ID an old 7 ft disc? #6  
"I don't mind going slow in 4wd, HST Low range, and using ALL 43 (or about 40 wheel) HP." This is Subsoiler technique.
A new, shear-bolt protected Subsoiler from everytfhingattachments.com is $385. Subsoilers ship UPS in two cartons. A 2 X 12" plow can plow 7" deep, max. A Subsoiler can cut, not plow, 12"~~14" deep.

VIDEO: tractor subsoiler - YouTube

ETA LINK: 3 Point Hitch Subsoiler


You can pull a 2 X 12" moldboard plow with your L4330/HST. These are usually available for <$600 if you shop Craig's List and eBay. After plowing you can likely sell the plow for the price you paid.

Mr. Natural still says: Get the right tool. A plow is the preferred primary tillage, sod busting tool.

I own a heavy Box Blade. In my experience this would not be good for the job and conditions you have outlined.
((However, after bi-directional diamond passes @ 12" depth with a Subsoiler, the Box Blade may work.))

LPGS I speculate would be better for smoothing than a Box Blade but I have no direct experience with an LPGS.


A sufficiently heavy Disc Harrow is a versatile implement.

You do not pull a Disc in LOW to smooth and mix soil. Disc needs to be pulled at a brisk pace. The problem is not the first pass, the problem comes in second pass when the soil is soft and tractor wheels and Disc pans sink 3" into softened soil and draft force doubles.

Tandem Disc Harrows tend to roll over, not cut, vegetation until you reach 24" diameter pans.

Your L4330 is the same weight as my L3760. You have six more horsepower.
 
Last edited:
   / ID an old 7 ft disc? #7  
Maybe consider a rotory tiller, 5 or 6ft?
 
   / ID an old 7 ft disc? #8  
What size is the entire field?

Once the three acres is agreeably smooth, what use do you intend for the entire field?
 
   / ID an old 7 ft disc? #9  
Listen to Jeff, he’s the man on this size disc harrow.
Cutting residual vegetation on this 2-3 acres will be difficult with smooth rear gangs. The notched discs on front cut the veg busting surface soil and the smooth discs are for soil finish work. I’d adjust to 60 40, with 60 percent of weight on from gangs and 40 percent on rear. It will take many, many passes to cut veg and smooth surface. Only takes time, effort and fuel…
Plan B Consider renting a heavier disc with all notched disc gangs for a day and use it to cut and chop that veg and surface soil… think 20 inch discs or larger. Once its broken open and chopped… then your new used [finish] harrow should be able to complete the project. 18inch disc should go 5-6 inches, avoid axles in the soil [love your bearings… don’t abuse them].
 
   / ID an old 7 ft disc? #10  
Hi guys. I've been needing a heavy disc, known around here as a "bog disc" to try to level out about 2-3 acres of my back field. This one came up on auction locally and looks like it might fit the bill. Especially if I chain down about 1,000 lbs of tree trunk on top.

Anyone recognize the maker? Any opinions about the sturdiness of it's construction? I'm not too sure about the "serpentine" frame. What do I need to check about it's condition other than the disc and bearing/axle condition?

View attachment 484761

Nice antique disc. A good restoration project, but not what you want for your job.

When I put in landscaping (about 1/3 acre) at my ranch 11 years ago, I had a new 2005 Kubota B7510HST tractor (21 hp engine, 17 hp pto), a King Kutter combination middle buster plow/subsoiler ($150 from Tractor Supply) and a 48" Yanmar RS1200 rototiller ($250) from my local grey market tractor dealer.

Use the subsoiler first followed by the rototiller. To smooth the soil I just used my Huskee riding mower with a water-filled roller and several DIY drags.

Huskee roller.JPGHuskee tire drag.JPGKubota rototill-1.JPGKubota-middle buster-1.JPGHuskee carpet drag.JPG

You don't have to spend a lot of $$ for a job like yours. Just use what you have and improvise a little.

Good luck
 
 
 
Top