A Guide To Stump Grinding

As an itinerant stump grinder for these past dozen years, I have experienced a variety of stump removal scenarios. I haven’t written this with the intention to impress, nor has it been written as the “be all to end all stump grinding method”. I felt there to be a need for a written description of what I do, amongst the plethora of visual and pictorial information out there. Perhaps this humble piece will inspire other stump grinders to make an effort with their written descriptions of how they grind away stumps with their machinery. If this collective information, was compiled and indexed, it may prove to be a valued written source of reference for all future stump grinders. I am fortunate to be able to draw upon my own unique mix of experiences (not necessarily connected with this subject), complemented with an ability to put this into writing — although how it is interpreted, remains to be seen. This is a detailed description of how I remove a tree stump with a professional stump grinding machine.

There will be deviations from this main topic, also describing my reasons, methodology, and events which led to the present action taken. Unlike many of my stump grinding peers who have relied upon YouTube videos to demonstrate stump grinding, nobody has yet—as far as I am aware— written a definitive procedural description on the salient points of this operation, for placement in the open domain. It is understood there are many other views with many other variations in procedure, reflected by variations of equipment types. My intention of basing my procedural description with a modified Carlton 2300 stump grinder, is to keep it simple, without all the “bells and whistles” of modern stump grinding machines. However, this old (1997) model has been updated with a Lombardini diesel engine to give it performance approaching modern machines. I have added a number of my own “bells and whistles” in the form of various gauges which I feel are important to gain a general understanding of machine performance. Further, old fashioned finger type cutter teeth are used. This is a personal preference based on cost alone. I also recognise the OEM improvements made to modern stump grinders, and do not intend for these writings to diminish those improvements in any conceivable way. Again I re-emphasise the use of an old model Carlton 2300 is to keep it simple in spite of the below listed changes to the machine. My wish, and hope is that some of this will spark additional thoughts and improvements to increased safety, and productivity in a potentially hazardous operation. Stump grinding is inherently a hazardous operation to people, pets, and property. The scope of this procedural description assumes a familiarity with all necessary safety equipment, and will only make occasional reference to such equipment within the context of my operational method and procedure. I will begin with a list of modifications made to this old Carlton 2300 including reasons:

  • brackets for securing a 2.5 mtr. horizontal, flood light mast at the machine’s top, and along its length. When working any distance away from base, It isn’t cost effective to complete a job on a second return to site if it is possible to complete within one journey. Winter evenings at the solstice here in England, begins at about 16:00. Working a few extra hours in the dark, will make a considerable cost savings. This prompted installation of a flood light attachment. to the machine.
  • pivoted brackets mounted in place of mud guards for securing rubber screens suspended from steel arms. Some manufacturers of stump grinders may now provide these screens. None were available at the time, so I made them up. After experiencing a broken window, as a result of stones being projected diagonally from the cutter wheel, such a screening provision became very immediate. I never operate without my mud guard mounted screens.
  • pivoted bracket assembly for securing a vertical mast of a three meter parasol used for all lengthy stump grinding jobs—rain or shine. A comfortable stump grinder, is a productive stump grinder.
  • bracket for securing a proper oil pressure gauge—not an idiot light! Most modern stump grinders have automatic switches to shut down the engine when oil pressure is lost. If this machine had one–I would still install an oil pressure gauge. An idiot light will not sense a reduction in oil pressure as when the engine warms up from cold, or when a possible leak may occur. Further, it can indicate approximate engine temperature once experience is gained with normal pressure/temperature comparisons.
  • bracket for securing an engine oil temperature gauge. This was a temporary installation because the oil dip stick had to be substituted with a sensor bulb immersed in the sump oil to gain accurate data. With a clear cool air intake, my engine was running at 90 C. That is quite hot and proves the point how important it is to keep cool air passages and air intakes clear and clean. I have nearly 4000 run hours on my diesel engine with NO black or white exhaust smoke!
  • bracket securing hydraulic oil temperature gauge. This is also a current temporary installation while data is collected and can be more accurately referenced against the pressure gauge. A permanent installation with a combination oil level and temperature indicator will be installed at a later date.
  • A sheet metal screen separating the operator from hydraulic hoses was installed just behind the hydraulics control levers. Most modern models have enclosures for hydraulic hosing, and must meet CE certification.
  • welded angle, supports for cutter wheel’s hinged (guard) shroud. When this guard is down in its operational position, it nestles between two welded angles giving it lateral support. The addition of these angled supports was found to be necessary when the guard makes contact with a portion of uncut stump which remained beyond the swing limit of the cutter wheel.
  • brackets to secure a permanent electric winch above steering wheels. A twelve volt winch has been recognised as an essential on-board equipment. Occasions have required a winch to assist machine manoeuvrability, to fix a static position on a slope where driving the machine’s own stake into the ground is impossible. and to extract the machine from difficult terrain.
  • installation of lockable key operated emergency stop switch. CE compliance requires this switch.
  • installation of a fixed means to secure the cutter wheel’s hinged shroud in the down or operational position. CE compliance requires this.
  • central point greasing hub located within a cutout on the machine’s decking. Armored, sheathed, flexibile, hydraulic grade pipe, is connected to four underside (difficult to reach) grease nipples
  • fine mesh insect screen installed over engine cooling intake fan opening, complemented with a steel grid support fixed within air intake shroud. This eliminated the need to frequently remove th engine’s cool air ducting to the finned cylinders, for cleaning away debris caught between cylinder cooling fins. This was a frequent and essential task to prevent “hot spots” and to maintain efficient engine cooling for such a hot running air cooled engine. A water cooled engine has distinct advantages for operating in such a dirty environment.
  • A thick neoprene gasket placed beneath the chain drive cover. This gasket is a great improvement with keeping out contamination, and extending chain life. ( Modern stump grinders have hydraulic motor hub drives for each wheel. Chain breakage was always a risk, with the possibility of a runaway machine. That can’t happen with hydraulic motors at the drive wheels.)
  • complete sheet metal encasement of ‘V’ belt drive. Required for CE compliance.
  • Improved fixing/support bracket for shallow screen located directly behind cutter wheel. This bracket was made in one piece of steel stretching the length of the rubber screen. It provides additional screen support, and is quicker /easier to remove for screen replacement due to wear.
  • heavy duty spiral banding was wrapped around all exposed hydraulic hoses. A CE requirement to protect the operator from a hydraulic hose burst
  • Installation of thermocouples to the bearings for determining their average normal running temperature and to indicate excessive bearing play yet to be installed.

Transporting A Stump Grinder:

There are two ways of getting your stumpgriner down the road to a site; either by loading it onto a trailer, onto a truck, or into a van. I chose a VW medium wheel base, high top, turbo-diesel, panel van for the following reasons, and a description of how the stump grinder is stowed:

  • VW vans represent dependability for me. I’m onto my third change of van (all purchased second hand) and have never had a breakdown that wasn’t my fault.
  • the trailer option seemed to be hassle, with access down narrow driveways, turning radii too narrow, and a great deal of unnecessary monoeuvreing
  • I dont have a large enough lock up garage, which would require outside storage for the stump grinder and trailer making it subject to theft.
  • my van is dedicated to storing the stump grinder where It stays onboard.
  • I do all of my servicing and repairs with the stumpgrinder onboard. I carry all necessary tooling to perform minor field repairs e.g. changing a drive chain to the drive axle, or wedge belts for the cutter drive.
  • the stump grinder and tools are secure in the van with the vans additional security, eg. immobiliser, alarm, wheel clamp, and additional door and frame strengthening which has already prevented someone trying to lever the base of the rear doors upwards in an attempt to gain access.
  • I keep a set of steel ramps stowed onboard. These are also useful for gaining access in gardens with steps, or at a higher level.
  • a steel wire cable is installed between opposite anchor points next to the steel bulkhead separating driver from loadbay. At the cable’s centre is fixed a steel ring, through which the stump grinder’s stake enters, when the machine is stowed. This cable has two purposes. First use is when uploading the grinder. By extending its tongue to reach the steel ring fixed at the centre of the wire cable, then passing the machine’s stake through the steel ring, allows the machine to pull itself into position when retracting the tongue. This entry method is preferred over reliance on the grinders wheel traction which is minimised on wet days, and also because its wheels must climb over, and on top of screening stored on the vans floor. Second use is as a secure fixing point while the van is in transit.
  • within the rear of the loadbay, is a steel saddle fixed to the floor. ( looks like an upside down double “TT” ) It is bolted through the van’s floor, and through square plates pulling against the chassis underside. The machine’s cutter wheel nestles between two verticle plates. A pin passes through both verticle plates and a cutter wheel bolt hole, where the tertiary pockets use to be fixed. ( they didn’t do any work, so use was made of their intended bolt holes )
  • the machine is firmly stowed using this method. Indeed, it stayed in place, with my van on its side in a drainage ditch! ( the ultimate test )

Downloading the Stump Grinder By The Numbers

  1. open rear doors, unsecure ramps from their stowed position, slid out ramps, and fix them to door sill with pins
  2. open sliding side door, start the stump grinders engine, retract tongue slightly to pull against steel cable thus allowing release of tension on cutter wheel stowage pin, for its removal, and raise the cutter wheel away from its floor saddle.
  3. engage axle drive or “free wheel” valve, reverse machine slightly, just enough to allow release of tension on steel cable allowing extraction of machine’s “T” stake from the steel ring fixed to the cable.
  4. pin the machine’s stake to its normal stowed position, and drive stump grinder down the ramps.

Determining Safe Access

  • after stopping the grinders engine (remove key), do a “walk-through” along the machine’s intended route to the stumps. Depending on machine’s width (owing to extension dual wheels fitted) determine an easy unobstructed access.

For information on Stump Grinding Southampton click here.