Zero-Turn Stump Grinder

Zero-Turn Stump Grinder MOWERS Grasshopper zero-turn mowers are known for their wide range of implements but only Larry Roessler has a stump grinder on his “It’s really dirty with chips flying but it’s so nimble ” says Roessler “I can grind up a stump and then follow roots zigging and zagging as they do ” Roessler got the idea to build a stump grinder after renting one for $300 He had jammed his lawn mower into a stump on a new property He built it with the Grasshopper’s front pto in mind He bought a gearbox bearings hubs and a keyed shaft and coupler from Surplus Center He fabricated much of the rest with the help of carbide bits from CEI Supply “I went through plenty of bits ” he says The gearbox is mounted rigidly to the mower frame The cutting wheel rides on a spring-supported frame mounted to pillow block bearings on the gearbox output shaft The frame is made mostly from 1 1/4-in steel tubing and pivots on the mower’s toolbar The lift springs are from an old farm implement with one end 3 1/2 in from the pivot point The other end of the twin springs is connected to a post on the mower frame A threaded rod between the post and the springs lets Roessler adjust the tension so the cutting wheel will float A third light-duty spring between the cutting wheel end of the frame and a lever on the mower lets him fine-tune suspension A belted pulley between the gearbox and a pillow block bearing on the output shaft of the gearbox drives the cutting wheel “I had to fabricate an extension to the gearbox shaft to provide space for the pulley and the bearing ” says Roessler The cutting wheel is two pieces of 4 by 12-in 5/8-in steel plate They’re welded in a cross shape with a piece of 1/2-in plate in between to offset the grinding bits or teeth The 1/2-in sq bits are mounted in split hubs at the ends of the cross plates A third piece of 5/8-in steel is added to the cross plates to provide extra width for the split hubs “The heavy welding caused the plates to warp and I had to press them straight again ” says Roessler “In hindsight I should’ve bolted the stack together and then put several small welds to hold everything in place ” The cutting wheel rides on a shaft suspended from the front ends of the frame with a 3 1/2-in pulley for the belt drive The pillow block bearings they ride in can be adjusted to take up belt slack The ends of the shaft have bolts with heavy washers to prevent the belt from walking “Initially I attached a linear actuator between the mower frame and the cutting wheel with a toggle switch to lower the wheel into the stump ” says Roessler “However the load on the wheel would be erratic and it would either jam or run with only a light load Instead of it I simply apply pressure with my feet The footrest can flip forward or backward to shorten or lengthen leg travel ” Grinding stumps is rough on the pto shaft spline acknowledges Roessler “After replacing two mower shaft splines I incorporated a 1-in keyed shaft for the mower pto The gearbox now mounts to the pto shaft with a keyed coupler and I’ve had no more problems ” The cutting wheel operates at the same rpm’s as the Grasshopper’s 14-hp motor upgraded with a bigger carburetor to 16 hp Roessler installed a metal shield over the cutting wheel and a piece of rubber tire underneath the frame to deflect some of the chips Enough fly back at him that he always wears a face shield With only $60 more than his previous rental rate invested Roessler is more than satisfied with how his stump grinder works “We had a major windstorm come through earlier this year and it blew over trees ” says Roessler “I had relatives coming out of the woodwork needing stumps ground out I don’t charge Mostly I do it for the free meals ” Contact: FARM SHOW Followup Larry Roessler 1131 N Old Bruceville Rd Bruceville Texas 76630 ph 512-576-9589; Larry_Roessler@hotmail com

To read the rest of this story, download this issue below or click here to register with your account number.