I've got some creek bottom that is perfect for pasture. 30 yrs ago it was planted in Christmas trees, white pines to be exact, and I've cleared them out save for the stumps. The Scott in my Scottsirish does not want to rent a stump grinder, and the inventor side wants to craft one to fit the 3 point hitch/PTO of my restored Ford 8N tractor.

Havent got it completed yet, but so far I have a 2' diameter of plate steel welded to a scrap truck wheel. I clamped the wheel to my bench and spun it on the wheel bearing, then marked and torched it to true up the balance. Next step is to weld on some teeth, fix a 3 point hitch and try'er out. I'm thinking that if I spin it up over top of the stump, then simply lower it down by gravity digging say 8" below grade, then raise it up, move one grinder width and repeat the process I'll soon have the stumps taken care of. Long as I stay stationary whilst grinding the loading of the wheel bearing should work... I think.

Has anybody else ever rigged up such a contraption? Is my design concepty sound? Any suggestions for the material for the teeth? Commercial stump grinders use square spring steel teeth with carbide bits silver soldered in. Lacking that I'm thinking about torching slots in my round and welding in uniform pieces of old truck spring, angled in the direction of the cutting action like saw teeth.

-- Robin Norris (Robin.Norris@compaq.com), November 29, 2000

Answers

How large and how many stumps are you talking about? Are they far enough apart to where you could disk between them, plant forages and just let them rot out?

-- Ken S. in WC TN (Ken Scharabo@aol.com), November 29, 2000.

the stumps vary in size up to say bout 24" in diameter, were planted in rows, just too many to manage. Bout killed me trying to bush hog the area.

Rotting em out is the status quo if I don't get the grinder finished in the next couple of years, but with the sap some of em might just get hard and never rot.

/Robin

-- (Robin.Norris@compaq.com), November 29, 2000.

Im thinking the steel wheel wont be strong enough to stand up to that kind of use. When I was working x-mas trees a few years back,,, we would just go in a back hoe then out,, even in frozen weather,, Can you borrow/build one of those?

-- STAN (sopal@net-port.com), November 29, 2000.

I would put a slip clutch on the PTO shaft as well as an overide clutch, to save the tractor.

-- Hendo (redgate@echoweb.net), November 29, 2000.

Can you blow them out. Here in AZ we can go to the local "explosive" place and buy stuff to blow trees out of the ground. Used a lot for range clearing.

-- JLS in NW AZ (stalkingbull007@AOL.com), November 29, 2000.

Blowin em out would be more fun ;^), but alas the cost in grief from my safety concious better half makes that approach untenable. I had looked into the notion of making up some diesel/amonium nitrate slurry, but a buddy who served a stint as an army construction engineer told me the quantities I'd have to use would make that method problematic, the energy release of diesel/furtalizer is not that much. 1/4 stick of dynomite would be more appropriate, but I'd have to use a steel mat to keep debris from my neighbors property, and a crain to lift the mat etc...

As to the wear on the spring steel teeth. I've anticipated the wear factor, mostly from rocks/sand contact, but hey I'm hoping I'll be able to get through the 2 acres of stumps without having to replace the teeth. Even if I do have to replace teeth a couple of times, it will be worth it! I've got less than $50 in materials, and it would cost 10X that to rent stump grinder for the job!

As to slip clutching the tractor PTO, I've stalled out the 28 HP tractor with the bush hog before with no problems... the stump buster would have less torque than the bush hog, I think the engine will bog down prior to breaking anything...

/Robin

-- (Robin.Norris@compaq.com), November 29, 2000.

Have you taken into consideration that attachments like you are describing are made in machine shops and have saftey features incorporated to protect the operator. A welded design will undoubtly be at risk of spinning apart at high speed. Machined parts are milled and tempered. Please take this into consideration when designing. It may be easier to use a little lye drilled into the stumps to rot them or use hot coals to ground burn them out (thats how I get rid of red cedar stumps).

-- Jay Blair in N. AL (jayblair678@yahoo.com), November 29, 2000.

I've considerd this from lots of angles... preciate the comments...

The reasons I'm still considering this project are: 1. the PTO on an 8N only turns about 800 rpm. 2. the operators seat is 90 degrees and several feet from the cutting/bashing action 3. I'll be cutting into pine tree stump till the cutter is below grade, at which point the low rpm should not fling depris very far against resistance of earth, ie the action should be rather like a tiller.

All of the above reasoning questions the viability of the project. It is intirely possible that low rotational speed at right angle to the tracter back end will result in pushing the implement sidways off the stump... rendering the whole project useless..

I have never seen a comercially offered stump grinder in a 3 point pto driven rig... I wouldn't buy one, but would copy engineering design...

-- (Robin.Norris@compaq.com), November 30, 2000.

I know this won't help you, but perhaps someone else. I would have hired a dozer to come in and knock over the trees and then windrow them. Alternately, the trees could have been cut high enough to let the dozer just pile up the stumps. When the field is clear, hire a neighbor to come in and disk it multiple times to smooth out the field. Even though a dozer charge is high per hour, they can do a lot of work in an hour.

-- Ken S. in WC TN (scharabo@aol.com), December 03, 2000.

If you can find some pure lime,used in cement,drill a hole pour in some lime.and waite.it will burn up inside out

-- Nathan Snow (ivy1@hitter.net), April 09, 2001.

It sounds a bit hazardous Robin. Your spinning machine would be located by the tractors implement arms? I have visions of it banging left and right, fore and aft, as it contacts the solid stump material. Does the tractor put any downwards force on the linkages? If so you might like to consider fitting something like a, say 2 inch diameter, steel spike at the rear of the contraption so that the spike gets pushed into the ground first and steadies everything. An alternative might be to extend the axle of the spinner so that you have a solid pilot spike going into the stump first. I am thinking of what would happen if I tried to use a tank cutter in my electric drill without the pilot. Like I said, sounds dangerous, but what wizard fun!

-- john hill (john@cnd.co.nz), April 10, 2001.

I have the same dilema only with about 20 acres of red pine, 6" to 12" diameter planted six feet apart. In other words, several thousand stumps. Several acres were planted on the side of a hill. To prevent erosion I can't dig them out with backhoe or dozer.

I found a pto driven 3 point hitch stump grinder from Wikco at www.wicko.com/stump.html It works with 35 to 100 hp tractors. The problem is it lists for $4869.00. You might get some ideas though.

-- Jerry Coon (jtcoon@gtii.com), April 16, 2001.

I don't know, but I'm interested in what you have in the way of new information about carbide tips and how to attach them to a steel plate, where to get them. My idea is not a stump gringer but a hydraulic-motor driven brush saw mounted on a frontend loader or skid steer. I have many, many three and four inch saplings on 106 acres. I would like to create a 30 inch circular saw blade out of 1/2 inch steel using carbide tips. I need to know where to get them and how to attach them. I like your stump grinder idea...Go For It!! I believe it will work. When you've solved your cutting teeth problem, mine is very similar.

-- phil lemons (plemons@caprock-spur.com), May 02, 2001.

I am in the stump grinding bus sounds like you are on the right track but your teeth will not hold up I have tried them all but carb tiped are the best . But at 800 rpm you will shake everything apart you need to put in a gear box like one off of a old bush hog to turn your hub faster like about 1200 to 1400rpm. Next you might wont call someone who grinds on the job like you talking about most will give you agood rate 3to5$\stump or buy the hr and be done in 1 to 2 days. If you are not going to plow it I would only go 1to 2in down.

-- william gregory (gregory@panhandle.net), June 13, 2001.