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

Dataway · May 6, 2011

I would cover the whole thing with a 1/8" thick sheet steel cover similar to a tiller so a chain coming off causing a problem would be unlikely ... I'd attach the chains with half links welded to the drum anyway, so chains coming off would probably not be a big problem.

Rocks are rocks and dirt is dirt ... unfortunately things are not that simple here. Looking at the area I keep landscaped (about 3 acres) it looks like nice lawn from a distance. However, up close you can see the rocks showing here and there. Problem is that rock could be the size of a fist, or the size of a small car. Plowing is not an option, the plow would hang on a rock every 10 feet.

The Harley rake looks very similar to what I need.... but with chains that would allow it to contact immovable objects without destroying itself. I'm not looking for something that would have the power to pulverize all things in it's path... but something that will dig up, destroy the "soft" material and reveal what needs more attention to remove.

Bringing in top soil would be great, but covering a few acres with top soil would get pretty expensive. I guess the best description is a device that will strip the top 2" of soft material and leave it lying, then I can walk the area and see what needs the backhoe or some other means to remove.

Modifying a flail mower would probably be my best bet if I didn't build from scratch. I had the idea of using simple hardened chain because it would probably last forever, and be inexepensive to replace if it didn't. Although it won't dig or cut as well as hammers or knives...but hammers and knives won't fare well against the large rocks.

I routinely fabricate fairly large items, so the building wouldn't be an issue. The design and parts availability would be an issue. Gearbox, drive shafts, etc. I think I need at least about 5,000 fpm at the end of the chains, which mean over-driving the PTO about 250-300%. I'd only want to do a few hundred square yards at a time, plowing up or cultivating 3 acres at one time would require more of a time commitment in a short span that I would care to take on.

Now I'm picturing a Harley rake.... with chains instead of spikes.... mounted so that the chains engage the ground about 1" in depth, so a couple of passes would be required. If past experience is any guide, I'd spend most of my time getting the driveline and 3pt geometery right, the rest should be pretty straightforward.
JohnnyB

PS. Anyone know of a good source for right angle gearboxes? Some place where I can peruse the designs and order complete boxes?

PSS. Seems like most gearboxes are speed reduction ... I need speed increasing ... or should I go with 1:1 and over drive at the chain or belt?
Thanks

smiley · May 6, 2011

Old manure spreaders and some other farm machinery usually have angle drives and they're heavy duty and I believe 1:1 ratio. I just gave the neighbor one back that he gave me 3-4 years ago, it also had a built in shifter to engage/disengage.

You might also look at flail mulchers for ideas, this one is from Construction Industry Product Information | Construction Equipment. They aren't intended for tilling but do quite a job of it if run to close to the ground.

If you get this rig going maybe you can hire out to the govt for small mine clearing jobs as in second photo.

Check this one out too. It's listed as a flail mower/tiller. http://www.ironsearch.com/Farm-Tractors/SmartSort-Equipment/BCS/Tiller-Walk(d)Behind/1474121.aspx

smiley · May 6, 2011

Dataway,
You got my curiosity up and here's one I never imagined existed. I've crushed a lot of rocks in the gravel pit but never knew a 3pt rock crusher/soil conditioner even existed. It says it does up to 8" rocks.
I'd hate to see the price of it.
http://www.seppi.com/en/mulchers-mowers/stone-crushers-tillers/midipierre.html

Dataway · May 7, 2011

Smiley,
Yep...that's the idea, except I can live without one that will eat rocks and stumps. In my searches I came across a company .... I think their biggest unit handles rocks up to 12" and stumps to like 18". Something like 300hp required and it's weighs like 12,000 lbs. I couldn't believe it was possible to make such a thing ...but they have a video of it in operation.

I see you are from upstate NY. So am I, in the Saratoga area, close to the Adirondack state park, I'm up about 1600 feet... so you know the terrain up here. Hard to believe any machine would handle "mulching" 12" diameter quartz granite basketballs we have up here

I mean these are the rocks that the glaciers couldn't mulch, there's not a "soft" rock anywhere on my property.

I found this place Surplus Center - Hydraulics, Engines, Electrical and More doing a TBN search. Looks like a good source for gearboxes.... guess I could over-drive the unit at the side chain/belt drive rather than at the gear box. Slippage shouldn't be a big issue unless I got it tangled up in too much brush or vines.
JohnnyB

PGBiodiesel · May 7, 2011

A heavy duty flail mower is just what you need.
They have hammers designed to handle rocks.
They might not pulverize them to dust but the mower won't break.
The hardened chains and flails are replaceble if needed.

If making your own:
Why do you think such high tip speed is needed?
1100rpm is 36 blows per second with your design.
If high tip speed is really needed, just increase the diameter of the tip.

If you welded a large half link on, then used a shacke to attach the length of hardened chain, and used say 1 1/2 the length needed, you could feed out the chain as it wore down.

Working alot of granite will wear down even hardened steel.

Goodluck

smiley · May 7, 2011

Dataway,
I'm over Utica way but know your area well. Used to run to Speculator, Lake George and Montreal a lot after high school. Also worked construction in the Adirondacks a lot of years so know all about your granite boulders. I remember one that was to big to move so we blew it and one 6" chunk went through the mat and through a window about 100 ft away. Most of our rock over this way is limestone and shale but occasional granite boulders show up.

quicksandfarmer · May 7, 2011

What you need is a stone burying machine -- see this video:

YouTube - Perfect Earth Stone Burying in North Canterbury

The way it works is it picks up a load of dirt and puts it down so the biggest stuff is on the bottom and the fine stuff on top.

I've never actually seen one of these machines but I've dreamt of them. I have similar soil and I'll say that what you don't want to do is take the rocks out of the soil, you'll just make a bigger mess.

smiley · May 7, 2011

quicksandfarmer said:
What you need is a stone burying machine -- see this video:

YouTube - Perfect Earth Stone Burying in North Canterbury

The way it works is it picks up a load of dirt and puts it down so the biggest stuff is on the bottom and the fine stuff on top.

Here in the Adirondack region we have a machine that puts the biggest stuff on top and the finer stuff on the bottom. It's called winter.
A lot of our highway rehab work was what is called frostheaves. Where the freeze thaw cycles can push the stones right up and through the roadbed. We dig em out to below frostline, fill it with compacted gravel and hope there's no others nearby to do the same next year.