Need to build a V8 wood chipper / shredder

Thanks William… What you mentioned is what I had in mind. A truck is cheap down here, and has a lot of power. That power—with the proper skill set and design—could be transferred into some kind of chipping/shredding mechanism.

The truth is that I’m not much of a mechanic, or fabricator, and I don’t think I have that skill set. I would need to see a well-documented similar project for me to emulate, and even then, I would need to bring in some local welders and fabricators (also very affordable) before the V8 project could ever take place. I’ll come back to this for sure… Might be a year or two, however.

For now, I think it’s smart to focus on the small shredder. All the parts would be water jet / laser cut, or purchased. Pretty easy to assemble too.

In the meantime, I’ll keep my eyes out for V8, DIY chippers and shredders. If something comes along that is similar to what you describe, I’ll be sure to jump on it fast. I still think it could be done for around $2k… When you consider the cost of an industrial chipper down here, that’s at least 5-10 X the savings…

I really like your post, and how you laid it all out… If you ever decide to build it, let me know!!


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Troy, where are you? Bad soil and jungle sounds like the Yucatan, maybe Quintana Roo or Chaipas. If you are anywhere near Veracruz, you can look aroung the places where they scrap out ships and boats. It would be perfect if you coud find a sheave from an old flat belt drive like this;

You would overlay this on the original steel wheel and mount the blades to the face. Then, you have to build a striker bar and an enclosure. Some chippers use a wheel with cutters on the side. You could build a turntable like a merry-go-round right off the ground and have the cutters on the edge facing upwards. The truck tire would sit right on top of the turntable to friction drive it. They made some brush hogs like this.
Good luck.

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My two cents. I would fill a tire with water instead of concrete. The water will flow in the tire and automatically balance it. TomC

Hello Mr. Tom

Would filling a tire with a fluid vs a solid decrease the flywheel effect ?


Maybe if it had shallow paddles inside?

N0 Mr Wayne The flywheel affect is just dependent on weight. diameter, and speed (I think). Now the water may be a slight bit lighter than cement but the advantage is in the balance. If a cement wheel is a little out of balance it is out for ever. The water will slosh around a little bit as the tire starts to spin, but in a short time the water will start turning in the tire at the same speed as the tire. At this point the water will be out to the furthest diameter of the tire and will BALANCE the tire perfectly. As I understand it it doesn’t just balance the tire it balances the tire/ rim/ and brake drum.
They use to sell a hool a hoop That was partially filled with a liquid. It mounted to the rim flange on trucks and would balance the tire Haven’t seen them in years. I don’t think the plastic held up. TomC

I would think that for your tire to automatically balance and retain the flywheel effect, that you would have too put multiple (+/- 8?) baffles inside the tire. I have no idea how a guy would successfully put the baffles in though… :/. I think that a plain water filled tire would lose a lot of the flywheel effect (as Wayne said), because when the flywheel encounters a sudden load, the water would keep spinning while the flywheel slowed down. It would probably help if you made your water into a syrup like consistency, but it would still have a “soft” flywheel effect. You may also have problems with being too far off balance at startup. (if the tire was not entirely full, then the fluid would drain to the bottom side and become lopsided.)


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I had the same thought… There would have to be some sort of paddle system / baffles inside the tire. But it would still have to have enough room on the edges, or near the tire wall for the water to be used for the balancing effect.

It’s a very interesting proposition, but I would think that if you were to go about the trouble to include a baffle system, you might as well go the concrete route, and use a traditional tire balancer to get a perfect balance… Seems like a lot less work.

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I agree, concrete would be a lot easier. I assume you would cut a hole in the top of the tire to pour the concrete into?

If I am understanding you right, you are describing a concrete flywheel and a water flywheel side by side on the same shaft. If so, I am not sure that the “water-wheel” would balance irregularities in the drive train and concrete-wheel. It makes sense to me that a water wheel would balance itself, but I don’t see how the said wheel would know how balance other irregularities in the system. Maybe I am missing something.

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I am building a mechanical hatchet for splitting up rounds sort of like Herb Hartman’s setup and I planned to pour in 1/8th inch screened stones in a tire for the flywheel. That will not set up like concrete but will that act like water then and loose the flywheel effect?

I think you could make your “stone-wheel” work pretty good if you bolted a few fins to your rim, and then filled your tire as chock full of stones as possible. I think stones would have an advantage over concrete as they would be denser, so long as you can keep them from moving around in there. I rather doubt that the stones would self balance, although tha would likely be unnecessary especially at lower RPM’s

If you add the fins could you not add calcium to the water for greater density like you do for standard weighted tires?

Guys you are over thinking this water flywheel thing. For 75 years we have been putting water/calcium chloride in farm tractor tires. We do it for additional weight and better traction, BUT, I can tell you from experience, that it also smooths out the ride when you are running on the road. Most tractors for some reason will develop a “lope” when going down the road and the water in the tire will eliminate that. Yes the tire is our of balance for a few seconds, but it very quickly gets up to speed with the tire.
Don; your stone idea anint so good. The dry stones will not spread out into the whole tire, they will have a tendency to stay in a clump. Sand would be better but again, sand will be slow to spread out. Stamp sand mixed with some water has been used in earthmover tires. The problem was the grit of the stamp sand wore the inner liner of the tire out, making them loose air. Water is the best and add some antifreeze if you live in Michigan. ( kidding Don Any place that sees freezing weather
Now the question that none of you have hit upon, and I have been concerned about, is “Hoe do you get water into the tube?”. I looked at my adapter last night. ( been 30 years since I last saw it.) It is made for inner tubes that have a core as all tubes do but, the part that the core screws into also is in another piece that screws into the basic valve. So the threaded part that goes onto the tube is larger than your normal auto valve stem. On the other end of the device is a female thread that fits a garden hose. Between the two is a solid piece that has a hole drilled in from the side and a simi hollow screw goes into the hole as a bleeder valve to relieve the “air” pressure as the tire fills up. The valve stem has to be in the UP position when filling to relieve the air pressure. You will have to stop adding water when the tire gets inflated and remove the water hose to let the air bleed out. Then reinflate with water until the tire is almost full.TomC

I guess I’ll add my two cents, I know the lope you are talking about Tom and how they don’t filled! In my opinion that doesn’t have anything to do with balance but weight!
Water won’t do a thing for flywheel type energy, those talking bout baffle how would you put baffles inside a tire wheel assemble???
Flywheel type energy will only do good when power at one point only in the circle is needed, continuous power like a shedder needs continuous power!
My power hatchet doesn’t have anything in the tire besides air and added weight wouldn’t do a thing for it except make it turn harder! Herb H

Well fellows I’m experenced use with TomC on the spinning water balacing.
PNW wetside our fields are smal forcing many tractor pavement hops from field to fields. Done it both ways. Filled. Non-filled. You defiantly want the 80% liquid filled for high gear, high speed road travel.
Most you all actually can see this easy.
All of the new washing machines DO use retained water self balacing. Try it. Unbalance a load. Spin it up. Watch it self correct. Old machines pumped out all of the water and then would spin shake/floor-walk.

This particular angel on the head of a pin back and forth hasn’t cut a single piece of wood.
TroyM not to be argumentative; but you have been reading the wood fuel consummations to feed a power loaded V-8 beast?
How do you ever feel you will come out wood use ahead having to feed this woodfuel hog and have a net gain?
This is why all other go with 2.5 kW to 5-10 hp wood processing systems.
I remember well Ben Perersons Deathsheads Chevy V-8 high speed auger/chipper. Why it got set aside. Then ChrisKy’s V-8 woodprocessor building up that keep getting more nad more involed and heavy/complex. Review why he set this aside and converted to the slower lower power wood processing system. SouthAfrican PatrictJ could have woodgas a big IC engine for his mills woodchunking. He went with a lower power/slower system. Why? He knows the true cost in energy/maintnece to force things faster for no purpose other than a speed brag.
Bannchi screaming V-8 is nice for ooh-rahs as long as you only having to dump the fuel in for a 1/4 mile, speed records, and use-it up one race 400’s and 1000’s.
Commercial chippers the cost to contain is paid MAN-HOURS and time-on-location. Chipping speed matters!
I’ve always ran my V-8’s for the long haul with the lowest fuels use consummations. Used a 6 cylinder in preference when I could. Liked a 2000 cc and sub, four cylinder the best of all.
Every thing does not have to be such a big save time deal. That’s dino-fuel habit talking.
Hand splitting wood rounds teaches well to conserve energy couse it will aways be a long haul day wood sweating.
Bucking hays does the same teaching.

Steve Unruh


I think the formula for flywheels you mention assumed that there are solid and have no slosh/flow factor to them.

I remember as a kid that my local “science fair” had a display on the “Conservation of momentum”: a very large (maybe 5 feet in diameter, 3 inches thick) plexiglass wheel filled with colored oil that must have weighed several hundred pounds. It took a bit of spinning, but soon all the fluid was spinning at the same rate as the plexiglass wheel.

At which point, even a child could stop the wheel fairly quickly. The fluid would keep spinning/churning/moving for a good minute or two after the wheel had stopped.

The law of “Conservation of momentum” states that an “object in motion will stay in motion, until acted upon by an outside force.”

Because the water in a tire or the oil in the plexiglass wheel has very little friction (‘outside force’) on the walls of their vessel, the fluids would continue to spin independent of the wheels/tires they were contained in.


Ok Brian, you make a good point. TomC


All my original suggestions were for low-tech. I’ve spent years in places like Mexico and India, etc. Keep in mind that the chunker is only working a fraction of the time. Waynes makes one cut per revolution. You can cut way down on HP if you go up on mass. Commercial chippers have both mass and HP because they are continuous feed. My suggestions were all aimed at getting RPM down for safety’s sake. On one side of the axle, there would be 2 tires that had been cut open and filled with concrete. It weighs 120% more than water. I too have filled tires on my Farmall 560 and they definitely weigh a lot. Concrete is cheap. On the other side of the differential / axle, you need a cutting wheel. You could probably even laminate it up from hard wood and make a steel band for the outside. It needs to be big enough to give you good surface speed even with low RPM. The number of cutters would be dictated by the HP.
All things considered, you are probably better to use a Jap engine and trans. You need to have a clutch or disconnect to get the mass up to speed. Truck refridgeration units have a big centrifical clutch to get the compressor up to speed. I have an extra 2 cyl gas enging that has this setup.
if you want a simple low-tech design, you can mount a small engine on the frame above the drivesaft (between 2 center-support bearings) and run belts around the drivehaft with a belt tensioner. Theer are lots of possibilities.