Eterra - Stump Grinder - User Manual - Rev 1.0
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Eterra - Stump Grinder - User Manual - Rev 1.0
11/04/2019
Page 8 of 17
2.2 Theory of Operation
The Eterra Stumper is a hydraulically operated grinder that uses your existing controls and hydrau-
lics to effectively grind stumps. The Eterra Stump Grinder consists of a direct drive grinder head
that is mounted on a forward facing mount. The head is powered by connecting directly into the
skid steer hydraulic auxiliary system. The skid steer hydraulics provide the oil flow and pressure
necessary to operate the stumper.
The minimum hydraulic system requirements should be 18GPM at 2500PSI for this series of stump
grinders to work effectively. Too low of flow and/or pressure will cause the stump grinder to stall
and run slowly. Be sure to maintain proper system filtration of your skid steer loader.
By lifting your boom arms and moving the grinder teeth into the stump, you can effectively grind
more material in a much faster means than with any other stump grinder. When pushing against
the stump and keeping the wheel under constant tension, the right amount of force is applied to the
wheel for the power exerted, which will allow the cutter teeth to bite off just the right amount of ma-
terial. As long as you keep it within the range of the tooth depth, you will limit the amount of stalling
experienced by the wheel even in the toughest material.
There are special blocks fitted to the wheel in front of the cutters called rakers. These rakers pro-
tect the cutters from damage should you hit a solid object. They may be replaced when worn so
that the cutters maintain maximum protection. This is an easy process that will enable your cutters
to last much longer than if they were to be removed.
2.3 Pre-Operation Checklist
• The Eterra Stump Grinder is designed to ensure years of trouble free use. A poorly maintained
machine is an invitation to expenses and trouble. We recommend that before operation that
this checklist be followed to ensure trouble free operation.
• Give the machine a “once-over” for any loose bolts, worn parts, cracked welds, hydraulic leaks,
frayed hoses etc. and make necessary repairs. DOUBLE CHECK the Stump grinder bolts and
coupler as well as mounts to insure nothing has come loose as you risk the stump grinder head
falling off if not properly inspected.
• Check for excessive wear as well as cracks in the cutter wheel. Replace as needed.
• Be sure that there are no tools lying on or in the machine.
• Lubricate the main bearings daily or after each 8 hours of use. There is a greasing zerk located
near the front of the drive housing.
• Make sure all hoses are clear of cuts, abrasions, worn spots and pinch points before operating.
Check that hoses do not get caught in the pinch areas of your skid steer boom.
• Check the tire pressure and make sure they are inflated to their recommended pressures. Con-
nect to Skid Steer and check mechanical Skid Steer connection point for wear that could cause
Stumper to fall off. Repair any damage as needed.
• Connect all three hydraulic lines to Skid Steer.
