What size tandem disc for my 50hp tractor?

[Poopdeck Pappy]

I really need a tandem disc and I've found a well-built, gently used 6 foot one that has a box frame and 20 18" discs with 7.5" spacing between the discs. It is a 3 point hitch model and weighs about 725 pounds, so that's about 36 pounds per disc. I'd like it to be a little heaver, but I would be using it only for secondary tillage on soil that has already been chisel plowed.

I have a Kioti DK50SE HST, and I think it could pull an 8 foot disc, so I'm wondering if 6 foot one is undersized for my tractor. Unfortunately, I have not been able to find a decent price on a 7, 7.5 or 8 foot box frame disc in my area.

I'm tempted to pull the trigger on this one even though the narrower width seems to waste some of my tractor's available power. I only have about 15 acres to disc with it, so a 6 foot swath versus a 7 or 8 foot swath won't cost me that much extra time.

So what size disc are you guys pulling with your 40 - 50 hp tractors?

 

[jeff9366]

PDP: Think of Disc Harrow size as pan diameter first, then width. Most of Disc Harrow weight is in the pans and penetration is primarily through implement weight, secondarily through adjustable gang settings and the pulling power of your tractor A Disc Harrow with 9" spacing between pans will cut better than a DH with 7" or 7-1/2" spacing between the pans, which is more "smoothing plow furrow" spacing. (More pans = more float.)

TractorData.com Kioti DK5�SE tractor information

Your DK50SE is 4,300 pounds, bare tractor + 4-WD. You can pull a Tandem Disc Harrow with 22" diameter pans seven to eight feet in width, bearing in mind cutting width is LESS than overall width. A Disc Harrow with 22" diameter pans is usually heavy enough to cut sod with moist soil below without previous plowing. Weight per pan with 22" diameter pans is 75 pounds to 80 pounds per disc.

You will have to make two passes with the 18" diameter pans and 36 pounds per pan, when chopping clods and smoothing plow furrows in medium or heavy dirt. This light Disc will not cut sod satisfactorily, even with notched pans. Its working width will be LESS than its 6' overall width.

Here is my review of my previous Howse DH with 18" diameter pans and 9" pan spacing: http://www.tractorbynet.com/forums/attachments/274971-howse-16-18-disc-harrow.html?highlight=
The Howse was max my little B3300SU (1,930 pounds, bare tractor) could pull.

I adjust my current Monroe Tufline Disc Harrow with 20" pans frequently. Aggressively adjusted you have pretty high DH furrows, although much lower than plow furrows. Adjusted less aggressively the seed bed can be quite smooth. Reading here, it seems most just set gangs at an aggressive angle then never change them.

Some Discs have easier to adjust gang angles than others. My Howse, with clamp plate adjustment, required removing two bolts and loosening four others with a wrench. My Monroe Tufline DH, with adjustment via holes in the adjustment lever, requires only the removal of two hairpin clips and associated two 1/2" pins by hand. The Moroe Tufline is much faster to adjust.

http://www.tractorbynet.com/forums/...ing-three-point-hitch-mounted.html?highlight=

 

[kthompson]

I have a M6800 two wheel drive Kubota with manual trans. I use a pull type disk with 20" blades and not sure the spacing without measuring it which I can if you need me to and can also get the mph for the gearing later. It is a 28 blade disk with notch blades totally. The cutting width of the front is about 10 feet and the back a little wider. No idea the weight of the disk but not an angle iron frame but out of square tubing.

I am one who has set his gangs not as aggressive as possible but near that and seldom change it. It cuts good at the angle it is set and and just as important it levels good as that angle. If the ground is hard it will not cut as deep as possible with the first pass but if chiseled plow it would cut to the axle if I would to lower the disk that deep but I do not cut to the axle due to wearing the bearing mounts. For me speed is important also and for again my tractor this as the max disk size I want. I can normally pull in high range 2nd gear with heavy cutting normally lowest is high range in 1st gear. IF I have to drop to low range the cutting action may be fine but not pleased with the way the dirt is left. Slow will cut fine but it does not shatter the dirt near as well.

But why do you want or need a disk? Is it to cut up trash or to break up the dirt from chisel plowing and leveling the ground? If there is trash to cut up and bury then disk, if to break up the dirt finer and level give consideration to what we call a field cultivator (think light weight chisel plow with many more shanks). It will be as hard to pull as a disk but to break up chisel plowed and level does a better job.