The machine, explained for Lewisville, NC
How a Stump Grinder's Cutting Wheel Works in Lewisville
The machine we bring to a Lewisville yard is a heavy steel wheel rimmed with carbide teeth, spun fast and lowered onto the stump a little at a time. Here is how the wheel cuts, which machine suits which yard, what it throws, and why a rented one is a different tool.
Free, no-obligation estimates. Tell us the width and how we reach it, and the whole job is quoted before we start.
How the cutting wheel works
A stump grinder swings a fast-turning disc of carbide teeth across the stump, shaving it into spoil a pass at a time. The wheel is a thick steel disc, and the teeth fixed around its rim are the only part that touches wood. The engine spins it at high speed, the operator lowers it onto the top edge of the stump and sweeps it side to side, and each sweep shaves off a thin layer that flies away as small wood chips. The trade calls those chips "spoil".
The machine is set directly in front of the stump, and the wheel is lowered slowly rather than driven in. Each pass takes it a little lower and a little further across, so the stump is worn away in layers, not cut off in one bite. The wheel keeps going after the wood above the lawn is gone: the "root ball" and the flare of the big roots are shredded the same way until everything sits about eight to twelve inches below the ground, the finish the trade calls "below grade". Then the wheel lifts, the spoil is raked, and the spot is level. How much wood comes off in each pass depends on the teeth, and the teeth are the next thing to know.
The teeth and how they wear
The teeth are carbide-tipped and bolted to the wheel, and stony ground wears them faster than clean soil. Carbide is far harder than steel, so a small carbide tip on the face of each steel tooth does the cutting while the body of the tooth takes the shock. The makers the trade runs, Vermeer and Carlton among them, fit their horizontal machines with carbide-tipped teeth for that reason. Each tooth is bolted on rather than welded, so a dull or chipped one comes off and a fresh one goes on in the yard. Wood alone dulls them slowly. A rock buried in the root ball or a run of gravel in the soil chips a tip in a single hit, which is why a stump set in stony Piedmont clay costs the machine more teeth than one in a soft garden bed. Sharp teeth take fuller bites, so the crew checks them between stumps. The wheel they ride on comes in three sizes.
The machines the trade runs
The trade runs wheeled machines on open ground, higher-powered ones for wide hardwood, and compact tracked ones for yards behind gates. Three sizes cover nearly every yard.
- WheeledA wheeled machine, towed or driven up to the stump, does flat lots and most residential stumps, and it is the workhorse of an open front lawn.
- High-poweredA high-powered drum machine turns faster and harder, and it is the one for large, dense hardwood stumps such as oak and hickory.
- Compact trackedA compact tracked machine fits through a standard 36-inch gate and reaches the tight back yard beside a house that a full-size machine cannot enter.
Which one comes to your yard follows from the width of the stump and the path to it, the two things we ask on the call. The tracks are what most owners ask about next.
Tracks, gates and turf
Rubber tracks spread the weight and pass an opening of about three feet, so a back yard can be reached without ruts. A rubber-tracked machine, "trax" in the trade's shorthand, lays its weight along the whole length of each track instead of on four small patches of tire, and it leaves drive marks much like a lawn mower's rather than ruts. On soft turf, boards go down under the tracks and spread the load further, so the lawn is neither compacted nor torn. The compact tracked machine is narrow enough to pass a standard gate, then works within inches of a fence, a patio or a driveway edge with little disturbance around it. What that machine leaves behind in a residential yard the family uses, and how the stump grinding goes from the gate to the raked spot, is the subject of our page on residential stump grinding.
What the wheel throws
The turning wheel throws spoil and anything caught in the stump, so guards go up and the crew works in protective gear. A wheel spinning that fast does not just shave the wood; it flings the chips, and with them any stone, wire or nail that grew into the stump, hard and low across the yard. A steel "debris guard" hangs behind the wheel to deflect what it throws, and nearby windows and doors are covered before the first pass. The operator wears the face shield, ear protection and boots that OSHA's tree care guidance and the North Carolina Department of Labor describe, and nobody else stands in the yard while the wheel is down. The bigger the machine, the further it throws, which is why the largest ones are run from a distance.
Tell us the width and the path to it
Those two things pick the machine and set the quote. We answer the phone or call back the same working day, and we quote the whole job before we start, with no surprise charges after.
More on the machine
Three further questions follow. What hard clay and stone do to the wheel, why the big machines are worked from a handset, and whether a rented one is the same tool each get a short answer here.
Hard and stony ground
Dense or stony ground can load the wheel and cost the machine its grip, so the work may go in more, slower passes. Packed clay holds the roots tight and pushes back against the disc, and a rock in the root ball can chip a tooth in one hit. Track-mounted machines are suited to heavy clay for that reason: the tracks keep their grip where a tire would spin. Soil type, rocky or clay, is one of the things that sets the price, so tell us what your yard is like on the call.
Why the big ones are worked by remote
The larger machines are run from a handset so the operator stands clear of the wheel. The disc on a big machine turns fast and throws debris a long way, and a handset lets the operator steer, lift and swing the wheel from outside that arc instead of from a seat beside it. The trade works to the ANSI Z133 safety standard kept by the Tree Care Industry Association, and distance from a running wheel is the whole point of the handset.
Whether a rented machine is the same tool
A rented machine can be smaller than the trade's and rarely reaches the depth the job needs, and it may be heavy and awkward for an untrained operator. Consumer rentals run about $150 to $280 a day plus fuel, and they seldom grind past four to six inches, which leaves the growth point behind in most species. A rented stump grinder is also heavy, powerful and hard to manage for someone who has not been trained on it. Verdict: the same idea, not the same tool, and the stump can come back.
What our neighbors say
Tommy came out the same week and took the old maple right down below the lawn. He raked it level before he left and you cannot tell where it stood.
We had three of them and a mess of raised roots along the drive. All of it went in one visit and the spoil went back into the holes.
Needed a big pine out before the new turf went down. Quoted over the phone, done two days later, and the spot was left flat and ready.
One wheel, one visit, and the stump is gone below the lawn.
Tell us how wide it is and how we reach it, and we pick the machine. Free, no-obligation estimates, the whole job quoted before we start, and the spot raked level when the work is done.