Stump Grinder

Overview

A stump grinder removes the stump and surface roots left after a tree is felled, chewing the wood away below ground level so the area can be replanted or paved. This model is a walk-behind petrol machine: the operator positions it over a stump, starts the cutter, and rocks a spinning carbide wheel back and forth across the wood, taking it down a few millimetres at a time until the stump is below grade.

The Petrol Engine is an air-cooled overhead-valve petrol unit. A Recoil Starter cranks it, a float-bowl Carburetor meters the mixture, and the Spark Plug fires it. Power leaves the crankshaft through the belt drive to the cutter wheel.

How it works

Cutting is done by the Cutter Wheel. A heavy steel Cutter Disc carries sixteen Carbide Tooth cutters bolted into pockets around its rim. As the wheel spins, each tooth strikes the stump and knocks out a small chip; because the teeth are tungsten-carbide tipped they survive grit and the occasional buried stone, and they can be rotated or swapped as they dull. The operator does not push the wheel straight in. Instead the Swing & Plunge Frame lets the cutter head swing sideways across the stump and then plunge a little deeper for each sweep, so only a thin layer is removed at once and the engine is never overloaded.

The Belt Drive & Clutch links engine to wheel through twin Drive Belt belts and a centrifugal clutch, so the teeth stay still while the engine idles and starts.

Construction

The whole machine sits on a wheeled Wheeled Chassis that rolls on Wheel Assembly wheels and drops a stabilizer foot to anchor against cutting forces. The operator works from the Handle & Controls, using the handlebar to sweep the head and the throttle to hold engine speed. A Debris Guard surrounds the wheel to contain the stream of chips, and the cutter shaft turns on sealed Ball Bearing supports. Common bolts come from a shared Fastener Set.