Flail soil destruction device

Dataway · May 5, 2011

I live in upstate NY with very rocky soil, you can't stick a shovel in anywhere without hitting a rock within 12" deep, from the size of your thumb to beach ball size and larger. I have a need to build a PTO driven device (for a BX2200) that will basically pulverize the top 2" of soil for new seed beds, leveling small bumps, holes etc.

I'm thinking along the lines of a attachment like a flail mower, but just using chains. I'm thinking a 4" diameter core, with 4" chains attached for a total diameter of 12". About 100 chains, offset from each other, in four rows at 90 degrees.

My problem is tip speed. With 540 PTO rpm, drive x's 2, that's about 1100 rpm, or about 3,300 feet per minute. Is that fast enough? From a design standpoint it wouldn't be too difficult to build soemething turning those rpms... if I had to drive it at x's 3, or 4, balance and bearings would start getting much more critical I think.

I realize it wouldn't pulverize rocks, small stumps etc. That's ok, I can go back through and take care of that, most of the ground will be decent "lawn" already, just needs to be destroyed and replanted.

My questions are: tip speed? Enough? Gear box ...readily available in the ratios and hp rating I need? Should I turn the rotor in the direction of travel, or against?

Seems like turning the rotor against the direction of travel would chew things up better as it re-chewed the pile built up in front. But I'm worried the pile would get too big, and the front will have to have some clearance for ground irregularities so things could get thrown out the front (the whole device would have a cover on it of course).

I have a fairly complete workshop, welders, benders, lathe, mill etc.

Any thoughts?
Thanks,
JohnnyB

BruceWard · May 5, 2011

Would a disk harrow do what you need?

Disc harrow - Wikipedia, the free encyclopedia

Old, very heavy disks work well to loosen rocky Arkansas soil before planting.

Dataway · May 5, 2011

I have a disc harrow already ... problem is there are so many rocks that it just skips over a lot of areas, all it takes is a rock the size of a baseball a couple inches deep to lift the harrow. Plus a harrow takes too many passes, and goes deeper (when it can bite my soil) than I want. I just want to totally destroy the top 2" and lay the debri back down nice and smooth.

I've seen giant forestry "mulchers" that are designed to do this very task, but I need a much smaller one. And much cheaper.

I've got all the usual stuff, disc harrow, rock rake, drag harrow etc. for the BX, and a backhoe on the NH. So far nothing has fit the bill. Think a tiller only going 2" deep and immune to rocks and stumps, that's what I need to build.

Problem is... I build it, and it doesn't do what I intend, then I would be upset

JohnnyB

PS. to give you an idea of what I deal with... during my spring "clean up" this week I decide to remove some rocks from the front lawn that were protruding about 1/2" .... two of them ended up beach ball size, the third was about 4 feet in diameter .... had to have my wife stand in the front bucket to get the front wheels of the 1715 just touching the ground enough to steer with the rock wedged in the backhoe .... no, she's not that heavy, only about 135 lbs

SPYDERLK · May 5, 2011

My thinking is, with a BX you dont have enuf HP to be effective if the device is more than about 1 foot wide.
larry

Dataway · May 5, 2011

Yeah I was kind of worried about the hp. I know flails typically have low hp requirements but over-drive them and it's going to use some power. I BX2200 will run a tiller no problem...but then it's turning much slower. I'm not sure how much hp slapping chains into the ground will take. It will only be engaging about 2" of soil though, and I can go as slow as necessary (PTO rpm is independent of ground speed). I'd like to see 3 feet wide anyway.

I can't imagine it would take much more hp than running a 44" wide, two stage snow thrower in 12 of heavy snow ...and the BX handles that fine. If necessary though I could build this and use the NH 1715 ...not huge hp, but more than the BX.
JohnnyB

jbooth · May 5, 2011

Sounds like a Harley Rake is what you need. Most are skid steer mounted but are made for use with tractors also. They are a pricey tool and there have been some threads on this site of individuals fabricating their own. There might even be some rental options. I know there are rental options here in KS.

Rustyiron · May 5, 2011

jbooth beat me to it, See if you can rent a small Harley rake or check to see if there is something on utube. I think that they are not so HP dependant, and you can allways slow down. I have seen many landscapers use them on a 3pt (putting in lawns) and I know that they will crumble some dirt clods up, but I can't exactley picture what you have for dirt. Dirt is dirt and rock is rock. It may be more practicle to buy a load of topsoil. But not as much fun as a welding project!!

BruceWard · May 5, 2011

I didnt realise you were trying to do this with a BX. The old, heavy discs I am thinking of weigh more than a BX.

I have seen a harley rake do a decent job of smoothing city pit gravel with large chunks of shale in it. That one was on a ~ 50 HP New Holland Diesel and it left chunks behind. I doubt a BX sized harley rake would do much to rocks.

SixHoeBob · May 5, 2011

If a flail chain comes off your device at high speed, what/who is going to catch it? I would chisel plow four inches deep in several directions, and then go over the area with the Harley rake.

aczlan · May 5, 2011

if I were in your shoes, I would look for a flail mower and replace the flails with straight knives (or forged hammers). That will be easier than starting from scratch

Aaron Z