Description
Wrestling 400-pound stump grinders up steep trailer ramps and muddy yard grades exhausts tree service crews before cutting starts. The Dosko 691 Series Self-Propelled Stump Grinder drives itself across rough jobsites using a hydraulic ground drive system. It carries a 20 Horsepower Honda V-twin engine. High ground clearance raises the center of gravity on steep side-hill contours.
The structural chassis utilizes 1/4-inch CNC flame-cut steel plate welded to structural box tubing to isolate severe shock loads from the operator. A massive 2-inch solid alloy steel cutter shaft rotates inside heavy cast-iron pillow block bearings protected by labyrinth seals. Power transfers from the Honda GX630 V-twin engine through an industrial electromagnetic clutch driving three banded cogged belts inside a protective guard.
Hydrostatic Drive Stump Processing Rig
Variable hydrostatic wheel drive moves the heavy machine across soft lawns, curbs, and trailer ramps under powered control. The aggressive cutter wheel chews through massive hardwood root systems beneath grade.
- Honda GX630 688 cc commercial engine delivers 20.8 net Horsepower for continuous root clearing.
- Hydrostatic wheel drive provides variable forward and reverse self-propelled transport across rough terrain.
- 20-inch solid steel cutter wheel carries 16 carbide-tipped Greenteeth for rapid chip clearance.
- Electric clutch engages cutter drive instantly at the flip of a handlebar toggle switch.
- Electric turn-key start eliminates recoil rope effort on the large commercial 688 cc V-twin engine.
- Side-discharge frame geometry clears wood chips out to the side away from the machine path.
- Adjustable handlebar incorporates operator presence controls and hydraulic ground drive levers.
Hydrostatic Transport Load Bench Data
Excavating a 36-inch dry maple root ball drops the Honda GX630 to 3420 RPM while fuel burn averages 1.42 GPH. Cutter shaft bearing temperature peaks at 150°F after one hour of continuous heavy grinding. The electromagnetic clutch coil operates at 138°F during continuous engagement. Operating noise levels reach 96 dBA at three feet during heavy chipping contact.
Commercial Tree Service Maintenance Rules
Commercial tree care companies, land clearing contractors, and municipal public works crews remove massive tree stumps fast with this self-propelled unit. Do not operate this heavy machine on steep ditch banks without winching support because the unit can roll over. Never engage the electromagnetic clutch with the engine running at wide-open throttle.
- Inspect and rotate all 16 Greenteeth cutting edges before starting each commercial grinding shift.
- Lubricate the 2-inch cutter shaft pillow block bearings with high-temp grease every 10 operating hours.
- Check drive belt tension and clean wood dust from the electromagnetic clutch housing every 25 hours.
Commercial Warranty Equipment Package Roster
Dosko protects the 691 Series with a 2-Year commercial frame warranty and a 3-Year commercial Honda engine warranty. The shipment includes the 20 HP self-propelled grinder, 20-inch cutter wheel, 16 Greenteeth, 12 Volt battery, hydrostatic drive, and operator manual.
