The UltraGrinder’s patent-pending cushioned parallelogram mechanism provides 3 inches of give in both directions. Combined with teeth on both sides of the cutting wheel, the mechanism makes it possible to cut both forward and backward, the company says.Photo: ArborWolf
ArborWolf says its new UltraGrinder is the only stump grinder attachment in the industry with a radial piston motor that increases productivity, a cushioned parallelogram mechanism for drivetrain protection, and teeth on both sides of the cutting wheel to enable dual-direction cutting.
The UltraGrinder attachment delivers the productivity of a dedicated stump grinder, according to ArborWolf, but at around one-fourth of the initial cost. It’s currently available for low- and high-flow skid steers – from 16-45 gallons per minute (GPM) – and ArborWolf says versions for mini skid steers and mini excavators will be available soon.
The manufacturer, which is based in Burnsville, Minnesota, says the UltraGrinder attachment was created for landscapers, professional tree-care contractors and farmers, among other markets, including the rental industry.
The UltraGrinder’s parallelogram mechanism alleviates excess pressure on the cutting wheel, protects the drivetrain and extends the life of the product, according to the manufacturer.Photo: ArborWolf
The UltraGrinder performs all the functions of other stump grinder attachments without any auxiliary or electrical controls, harnesses or circuits for raising and lowering, swinging or telescoping. Due to the way the UltraGrinder operates, those functions are not needed, the company says.
“If you can run a skid steer, you can efficiently and safely grind with an UltraGrinder,” said ArborWolf President Jerry Holman. “All you need to do is plug in three hoses and go cut wood.”
The patent-pending cushioned parallelogram mechanism alleviates excess pressure on the cutting wheel while protecting the drivetrain. The mechanism consists of a rubber torsion element and four heavy-duty link arms that connect the cutting head to the mount frame. When an operator begins to cut into a stump and applies pressure against the cutting wheel, the four link arms move against the rubber torsion element in unison to provide up to three inches of cushioned movement for the UltraGrinder cutting head and to keep it 90 degrees to the cut at all times.
ArborWolf says the UltraGrinder’s inclusion of teeth on both sides of the cutting wheel is an exclusive feature of its attachment and allows operators to cut safely in both forward and reverse directions through a stump.
With an UltraGrinder, the operator drives up to the stump, positions the attachment, drives forward and cuts. Once that cut is made, the operator simply lowers the unit several inches and backs up, making another cut in the process. With other skid steer stump grinder attachments, ArborWolf says, the operator has to lift the attachment, back up, lower the unit, reposition it and drive forward again to make another cut.
The company says operators can grind more stumps in less time with the UltraGrinder thanks to the radial piston motor. The attachment is 92-95 percent efficient compared with the approximately 60 percent efficiency of other skid steer stump grinder attachments, the manufacturer says.
“You can’t squeeze water out of a rock, so if a skid steer is rated for 23 GPM at 3,500 PSI, that’s what you have to work with,” Homan said. “What we’re doing with the UltraGrinder is extracting every ounce of horsepower from the machine and channeling it into the cutting wheel to achieve extreme productivity.”
