The brush cutter vibrates too much: causes and solutions

As you know, it’s normal for a brush cutter to vibrate—primarily due to the motor and the cutting mechanism (trimmer head, blade, or disc). It’s also inevitable—simply by holding the brush cutter—that these vibrations will be transmitted to your hands and arms. Over time, this can cause problems with circulation, bones, and joints, among other things, but even without reaching that point, it makes the work annoying and uncomfortable.

As manufacturers, we must minimize the risks associated with the vibrations of our brush cutters and specify, in the relevant manuals, the vibration levels they emit. During use, the vibrations can sometimes exceed normal levels: today we’ll look at why a brush cutter vibrates too much, how to resolve the problem, and what precautions to take to prevent excessive vibrations.

How to eliminate brush cutter vibrations

There are several factors that affect the vibration level of your brush cutter, starting with the type and amount of vegetation you’re cutting. When working on slopes, embankments, etc., you absorb more vibrations than when working on flat ground, because you grip the tool more tightly. In general, internal combustion brush cutters vibrate more than battery-powered and electric models. Trimmer heads cause more vibrations than blades and discs. Finally, given the same power source, power output, etc., models with a single handgrip typically vibrate more than those with a handlebar grip. On this topic, you’ll find a comparison of the different handgrips here.

Is your brush cutter vibrating too much? Turn it off and look for the reason why. If it’s a problem you can identify and fix yourself, go ahead and do so; otherwise, if you have an Oleo-Mac, contact your trusted service center. In addition to turning off the brush cutter, before inspecting it, disconnect the spark plug, battery, or power cord—depending on the power source—to prevent it from accidentally restarting.

So why does the brush cutter vibrate too much? There are several possible causes of abnormal vibrations:

• The type and amount of vegetation you’re cutting—for example, if it’s very tough.

• The trimmer line is too long or has uneven lengths in the different holes of the trimmer head: adjust the line lengths.

• The trimmer head is mounted incorrectly, meaning it’s off-center, not secured properly, etc.: simply reinstall it correctly.

• The trimmer head is unbalanced due to grass, dirt, etc., accumulated inside: open it and empty it.

• The trimmer head is worn out: just replace it; by the way, take a look at this overview of brushcutter trimmer heads.

• The blade or disc is off-center, loose, etc.: reinstall it correctly.

• The blade or disc is sharp but unbalanced: re-sharpen it so that the edge is even and all sides have the same weight.

• A blade or disc has been damaged by hitting a rock, a low wall, etc. It must be replaced: do not continue working, as it may break and send metal fragments flying.

• The brushcutter shaft is bent: this impairs the proper operation of the drive shaft that rotates inside it. The entire assembly must be replaced with an original spare part.

• The anti-vibration mounts are worn or damaged: depending on the brushcutter model, these may be located at the connection point between the motor housing and the drive shaft, on the shaft itself, or at the handle if it is a handlebar-style model. If you have an Oleo-Mac, contact one of our service centers to have them replaced.

Still haven’t found a solution? A brush cutter that vibrates excessively may have problems with the engine or transmission: in this case as well, contact the technicians at your nearest Oleo-Mac service center.

Do you have a gas-powered brush cutter? If the fuel tank cap isn’t tightly closed, the machine’s vibrations can loosen it, causing fuel to leak out. Fuel is flammable and can come into contact with the machine’s hot parts.

How to reduce brush cutter vibrations

While it’s not possible to completely eliminate brush cutter vibrations, you can minimize them. Here are our tips to protect yourself from excessive vibrations:

• Maintain a proper work posture:

• • Wear a proper harness: it helps support the weight of the brush cutter, so your hands and arms don’t have to work as hard. If it has padding at the hip level, it also helps dampen the vibrations transmitted to that area.

  • Wear anti-vibration gloves or gloves with anti-vibration reinforcement on the palm, such as Oleo-Mac cut-resistant gloves. They make all the difference: don’t settle for ordinary work gloves, which might actually amplify the vibrations.

  • Hold the brush cutter correctly, as indicated in the user manual: you can also see this demonstrated about halfway through our video tutorial.

• Before you start working, start the brush cutter to check for any abnormal vibrations.

• Also check the cutting implement:

• • The trimmer head, blade, or disc must be intact and properly mounted.

  • Whenever possible, depending on the task at hand, choose a type of trimmer line that generates minimal vibrations, such as our helical-section Spiral trimmer line.

  • Adjust the trimmer line length so that it isn’t too long or uneven between the holes in the trimmer head.

• Avoid working continuously for too long: keep cutting sessions short, take breaks, and alternate using the brush cutter with other activities.

• Perform regular maintenance on the brush cutter according to the instructions in the user manual, specifically:

• • Inspect the anti-vibration mounts: if they show signs of wear or damage, contact the service center to have them replaced.

  • Lubricate the bevel gear with special grease containing molybdenum disulfide.

  • Sharpen the blades and discs so that they are perfectly balanced.

If your brush cutter vibrates a lot and is getting old, consider buying a new one and look for a model with low vibration levels and equipped with anti-vibration systems.

We didn’t mention it in this article, but in addition to the classic brush cutter, there’s also a multifunction version: here’s when you should choose it.