Keep your horizontal grinder in peak performance by having a preventative maintenance plan.
By Ted Dirkx

The horizontal grinder is the ultimate cleanup machine with the capability to process materials ranging from brush leaves and logs to construction wood and green waste. Jobsite productivity is partially dependent on keeping your  horizontal grinder in peak performance. Below are six tips to help with horizontal grinder maintenance to help it perform at maximum efficiency.

Removing contaminants from the debris pile before grinding can help reduce wear and tear on cutters and screens, increasing the efficiency and lifespan of your horizontal grinder. Photos courtesy of Vermeer.

#1: Perform a Daily Walkaround
As you inspect the machine prior to beginning work on the jobsite each morning, take note of issues such as minor hydraulic leaks that could become larger problems if not addressed. For instance, discoloration or paint peeling on the frame or components around a bearing may indicate an issue. Spotting this early allows you to take corrective action.

#2: Clean Debris from the Grinder and Cooling System
Debris quickly accumulates during grinding operations. Periodically power washing or blowing off the machine allows you to spot upcoming problems that may be covered under the debris. Debris not only hides potential issues, but it could also trap moisture, causing corrosion.

Check and clean the radiator. Blow any debris away from the air intake screens. Also pay special attention to areas around the engine and hydraulic components where debris may accumulate. Clean around the hydraulic components to allow heat to dissipate.

Proper operator selection and training is crucial for maximizing horizontal grinder efficiency and minimizing potential issues.

#3: Sort Material to Minimize Contaminants
Horizontal grinder maintenance requires discipline. Contaminants, such as pieces of steel or foreign nonorganic materials, are a leading cause of excessive wear to cutters and screens, so it is important to remove contaminants onsite.

The heaviest contaminants typically find their way to the bottom of the debris pile. Since an excavator works from the top of the pile, this is often preferable to using a wheel loader with a grapple bucket. An excavator with a bucket and thumb does not pick up as many of those contaminants, and it is even better with a rotating clamshell bucket that takes a more precise grab.

It is also important to minimize that amount of dirt you run through the grinder. Dirt, sand, and small rocks are abrasive materials that wear the carbide off the cutter tips. Shake all stumps with the loading tool to remove excess dirt prior to running through the grinder.

If you grind a lot of wood waste that contains contaminants like scrap metal, you may be able to minimize unexpected maintenance issues through the use of the Damage Defense system. If the mill encounters certain metal contaminants while grinding, the Damage Defense system alerts the grinder control and automatically initiates the shutdown process. The system minimizes the likelihood of metal being pulled into the mill by reversing the feed system immediately, helping prevent significant damage to the grinder.

Maintaining wear parts such as cutter tips and screens is crucial to prevent premature wear and maximize the efficiency of your horizontal grinder.


Inspect key components regularly, pay attention to greasing schedules, check fluid levels and filters, and inspect belts for proper tension.

#4: Perform Regular Preventive Horizontal Grinder Maintenance
A preventive maintenance program that focuses on inspections can alert you to damaged/worn components early. Make sure the preventive maintenance program includes a timeline for inspection of key components, as outlined in the horizontal grinder maintenance manual. Pay attention to greasing schedules for bearings for the cutter mill/hammermill, conveyor, and infeed, as well as other components that rotate regularly.

Check fluid levels and filters (fuel, hydraulic, and air) regularly. Contamination is the enemy, especially in the hydraulic system. Check all belts for condition and proper tension.

#5: Change Wear Parts as Needed
To get optimum production out of your grinder and consistent material sizing, you need to make sure you are inspecting the wear parts involved with the grinding and cutting process daily. In some cases, these parts need to be inspected even more frequently. Cutter tips, screens, the anvil, wear plates and mill bearings must work together to size organic wood waste material properly. Neglecting any of these wear parts can cause premature wear to other grinder components.

For example, running cutter tips beyond their expected lifespan can inflict damage to the more expensive hammer component. Screens are another wear part that needs frequent attention. As they wear, openings expand. This results in product that is not sized accurately. Your output will start to get bigger and stringy as you lose vital cutting surfaces. The bars and metal around the screen will be rounded instead of sharp, so you can lose productivity and end-product quality.

A poorly maintained grinder is also less efficient. When cutter tips and screens are not maintained, it takes more horsepower to grind the material.

#6: Be Selective with the Operator
Owners and managers often allow too many operators to run a horizontal grinder. They are complex machines, so you want an operator familiar enough with the equipment that they can identify when there is a vibration or it does not sound like it should. If they can stop the machine when it does not sound or feel right, potential problems can be caught early.

If you have a different operator every day of the week, they do not spend enough time with it consistently. Developing a highly skilled operator who spends a considerable amount of time with a specific machine is something that is commonly overlooked, especially in bigger companies and municipalities where they want employee flexibility. That can lead to bigger issues.

Proper maintenance is crucial to keep your horizontal grinder running at peak performance and efficiency. By performing daily walkarounds, cleaning debris from the grinder and cooling system, sorting material to minimize contaminants, performing regular preventative maintenance, changing wear parts as needed, and being selective with the operator, you can help ensure that your machine stays in top condition. With proper care and attention, your horizontal grinder can be a reliable and effective tool for processing a wide range of materials. | WA

Ted Dirkx is the Sales Manager for Environmental Equipment at Vermeer. After studying composting and graduating with a degree in Environmental Studies from Central College, he joined equipment manufacturer Vermeer Corporation in Pella, IA. For the past 11 years, he has been traveling about 25 weeks a year, roaming North America and beyond, helping organizations set up compost facilities, manufacture mulch, clear land, and produce biofuels. He has presented at the Compost Council of Canada Conference, Canadian Wood Waste Recycling Association, Waste Expo, and USCC Conference on topics related to operational efficiency and maintenance. Ted can be reached at [email protected].

Always refer to the product’s operator’s and/or maintenance manual for safety messages and further instructions. Vermeer Corporation reserves the right to make changes in product engineering, design, and specifications; add improvements; or discontinue manufacturing or distribution at any time without notice or obligation. Equipment shown is for illustrative purposes only and may display optional accessories or components specific to their global region. Please contact your local Vermeer dealer for more information on machine specifications.

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