Pulling an 8 foot disk

   / Pulling an 8 foot disk #1  

Botabill

Platinum Member
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Mar 27, 2005
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576
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Ontario
I am considering buying a M.F.#25, 8' disc. Does anyone know if a small 26 HP compact tractor can handle a disc of this size? My tractor is a Kubota B2620.
 
   / Pulling an 8 foot disk #2  
I used to pull an 8 ft disk with my ford 8N, it worked hard at it but it did the work. Just makde sure you don't off set the gangs too much.
 
   / Pulling an 8 foot disk #3  
That seems like a lot of disc for the hp. Probably won't be able to go very deep. I assume it is a pull type disc. Discs work better with a little speed to move the dirt a bit. Pulling it slow may not work well unless the soil is loose. My 125 hp tractor handles a 21' disc well. Had a 12' disc on tractor with 70 hp and that did well. I like to travel 4-5 mph.
 
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   / Pulling an 8 foot disk #4  
It will pull it just fine !! Its when you set it in the ground you will have problems !! I doubt if when you lower it in plowed ground that it will get any traction. V
 
   / Pulling an 8 foot disk #5  
I've got a #25 Massey disc. It was an 8'-10" model when I bought it. I've since cut it down to 7'-6". (Removed one disc and one spool per gang) In plowed ground it would stop a 5500lb/47 hp tractor on even the slightest hint of a hill.

Another issue i'd expect is weight when you try to lift it. Unless you have a LOT of front end ballast (ie loader bucket full of dirt/lots of suitcase weights/ect) you'll be doing wheelies every time you got to raise it.

That's a lot of disc for that size tractor.

Next issue is hitching it. I've got a Kubota 7610 I bought to re-sell. It's a handy little sucker I must admit. But I've found a lot of my CAT I implements don't like to hitch up to the somewhat narrow CAT I hitch on the little Kubota.

All things equal though, that's a VERY good disc. IMHO, the best 3-point disc ever built.
 
   / Pulling an 8 foot disk #6  
5ft. yes.... 8ft. I wouldn't think so.
 
   / Pulling an 8 foot disk #7  
"The Drawbar horsepower needed to pull an implement is given by the weight of the implement ,including the average pounds of force applied per disc in the soil, (F) and the speed that the implement is pulled through the soil (S). The equation to find the necessary horsepower to pull an implement is FS/375."

Each disc is about 38 pounds of weight load into soil (@4-6mph) and most 8' disc-harrows have 20 or more discs. So weight load will be 38 x disks + weight of implement. If the disk weighs 1000lbs and you add say 24 disks, that's 1912lbs for F. Multiply that by a speed of 6mph and you get 11,472. Divide that by 375 and the necessary horsepower comes out to 30.592hp. If you reduce the speed to say 4mph, needed horsepower drops to 20.395hp. So you should be able to pull an 8' disk but at reduced speed.

This is, of course, dependant on your soil conditions. YMMV.
 
   / Pulling an 8 foot disk #8  
Just my 2 cents worth here, so my opinion doesn't count for much, but I think that a tractor that is pulling an implement should be able to handle that implement in any reasonable workable conditions. If it can not, then the implement should be smaller or the tractor should be larger. If you want to disk a couple of inches deep, maybe your tractor will work that disk, but if you think that you are going to work that disk to its maximum capability, well I seriously doubt that you would be able to do it.

Just my opinion derived from what I have learned with my experiences.
 
   / Pulling an 8 foot disk #9  
When I bury my 5ft. disk set up to the hubs (half depth of disk diameters) in bottom soil I'm glad I have at least 43 db hp and 4wd. I think 8ft. is too much for a 25hp tractor. On the turns if you don't lift them up it gets worse!
 
   / Pulling an 8 foot disk #10  
I really enjoyed reading ccw kens answer. This reminds me that scientists say hummingbirds cant fly. You will be lucky to carry that 8 ft set of disc around much less do any real ground engaging work. I have an 8 ft set of leinbach h/d and a 47 horse 4x4 tractor and if I have them set to cut and sink them it is all it wants. Please dont take me wrong just trying to help....
 
 
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