The Stump Beaver is a clever invention from engineer Graham Dewhurst, director of Geko Engineering. This is a stump grinding attachment which attaches to a mini excavator, popular in a number of markets including arborists but also landscapers, golf courses and construction firms.
As Dewhurst explains: “If you have a suitable excavator, then it makes sense to expand its use. Professional stump grinding will always be needed and arborists who can do it themselves can earn some useful extra revenue.”
The Stump Beaver is used primarily with micro and mini excavators as the 0.8t-to-2.0t class of machine. “This is where there is the highest volume of new sales in the UK. We have fitted grinders to several 3t machines where usually a flow restrictor is required to reduce hydraulic flow. But our main sales are to the 1.5t machine class, although the grinder works really well on most micro machines too,” says Dewhurst.
The Stump Beaver is supplied complete and ready to be attached with a custom-made bracket to suit the type of excavator. “We make the hitch ourselves to suit the customer’s machine. We also supply a storage/maintenance stand which holds the grinder to facilitate easy connection to the excavator. Once secured to the excavator the attachment and stand are lifted and the stand removed saving any lifting or manual handling. Once the job is complete simply refit the stand and lower the whole lot to the ground or trailer to de-couple.”
The auxiliary hydraulic circuit of the excavator supplies power to the grinder, while the grinder hydraulics prevent reverse wheel rotation, anti-cavitation and safe stopping even if the hydraulic circuit is suddenly closed preventing damage. A full guard over the wheel both limits the depth of cut and directs chips away from the excavator driver. The guard can be removed to give access for tooth changing and cleaning, again the stand allows for tooth maintenance when the grinder is removed from the excavator.
Dewhurst continues: “In use the process is simple, position the excavator close to the stump, engage the auxiliary hydraulics to spin up the wheel then use the excavator arm to lower the grinder and engage the stump then slowly move across the stump using the excavator slew function and let the chips fly.”
The grinder bracket can be rotated through 90 degrees to allow the bucket ram or dipper arm of the excavator to be used instead of the slew for those instances where room or access is tight.
Dewhurst adds that maintenance of the grinder is minimal, requiring only teeth to be kept sharp or replaced, and oil in the spindle bearing is changed each year.
Each grinder is made in-house by Geko Engineering and then delivered in person to UK mainland customers. “This allows us to meet the customer and fit the attachment to his machine to ensure everything is working correctly. During delivery we always try out the machine and grind a stump, we can then run through any operating queries answer any questions on the spot and give some tips.”