By
Matt
December 27, 2021Having a dull or damaged set of blades can severely affect the performance of a wood chipper. In this article, you'll learn how to remove your wood chipper blades and also how to sharpen the blades. The process is very simple and will ensure that your machine runs strong all season long.
Before we start, we also want to mention that if you're in the market for a new or upgraded wood chipper, then be sure to check out our list of the best wood chippers. The list reviews many different models, highlights their features, and answers common questions. Be sure to check it out!
Now let's jump into our guide on how to remove and sharpen your wood chipper blades!
The steps to remove wood chipper blades are easy and they are necessary for sharpening and replacement. If you want to remove your blades safely and quickly, then follow these simple steps:
The first step to removing wood chipper blades is a safety precaution to prevent the chipper from accidentally starting. An accidental start can cause serious injury or even death.
Preventing an accidental start in an electric wood chipper is very easy and involves unplugging the chipper from any electrical source.
Preventing an accidental start in a gas-powered wood chipper is also easy but not as intuitive. In a gas-powered chipper, you need to disconnect the spark plug.
The reason why disconnecting the spark plug prevents an accidental start is because small engines start by centrifugal force. When you pull the rope, it turns the crankshaft. This motion causes the spark plug to spark and ignite the gas and air mixture, causing combustion.
In a wood chipper, you may accidentally rotate the flywheel when you remove the blades. The rotation can cause the spark plug to spark and instantly start the wood chipper. The easy way to prevent this from happening is to disconnect the spark plug.
PRO TIP: You do not have to unscrew and remove the spark plug from an engine to disconnect it. The easier way to disconnect the spark plug is to remove the boot that sits on its top.
The second step to removing wood chipper blades is to remove the chipper hopper. The hopper is usually attached to the metal frame of the chipper using several bolts and nuts. You'll need a wrench or socket set to remove the bolts from the hopper and housing.
Some wood chippers are designed with a hinged hopper and removal is unnecessary. In these models, just unscrew or unclamp one side of the hopper and flip it open.
PRO TIP: Have a container nearby to temporarily store the nuts, bolts, and washers that you remove. In addition, based on our experience, it's not a good idea to have your son hold the container of bolts (especially if his name is Ralphie).
The third step to removing blades involves opening the wood chipper's housing to access the flywheel drum that has the blades attached.
If you're one of the lucky few to have a wood chipper with a hinged hopper (as mentioned above), then you already have direct access to the rotor and blades and can skip this step.
If you don't have a wood chipper with a hinged hopper, then don't worry. The process of removing your wood chipper's housing to access the flywheel is easy.
You should start by removing the bolts around the housing of the chipper and this should provide access to the flywheel drum. You may also have to remove a flail screen if your model has one equipped.
Each chipper is different so if you get confused about which bolts to remove, then check with your manual. The manual for your wood chipper will list the steps needed to access the blades.
The fourth step is to take a picture of your blades before you remove them from the chipper.
A photo will help you remember how they are installed, orientation, and which side should have the bolt head and which side should have the nut.
The fifth step involves removing the bolts that attach the chipper blade to the flywheel and rotor.
The bolts are usually attached tight and removing them requires some strength, especially if they are rusted. We recommend using a ratchet or any tool specified by your wood chipper manual. If you use another tool, such as grooved plyers, you could damage the heads of the bolts during removal.
PRO TIP: Use caution to avoid the blades falling into the machine when the bolts are removed. Unfortunately, some wood chippers are designed in such a way that if the blades fall off the flywheel, they can get lodged somewhere inaccessible and hard to reach.
The final step is to remove the blades. You have already removed the bolts securing the blades in the flywheel so they should come right out.
PRO TIP: A few wood chippers come with reversible blades. If your blades are reversible, then flip them upside down, rotate them, and reinstall. If you don't have reversible blades or if you've already used the other side, then continue reading as we will teach you how to sharpen your blades.
The steps to sharpen wood chipper blades are easy and they are necessary for high-quality wood chipping. If you want to sharpen your blades safely and quickly, then follow these simple steps:
The first step to sharpening wood chipper blades is to choose a sharpening tool.
Common Tools to Sharpen Wood Chipper Blades
The tool you choose is not as important as planning ahead to maintain the factory angle on the blade during the sharpening process.
Each blade is designed with a specific angle to ensure high-performance chipping and altering the angle reduces the chipper's performance.
So how can you maintain the factory angle during sharpening? The best way is to plan ahead when choosing your tool of choice. You want either the tool or the blade to remain in a fixed position during sharpening.
Here is an example of what we're talking about. If you choose a belt sander, then the belt remains at a fixed position during sharpening. As you hold the blade in your hands, its easier to maintain the factory angle because the angle of the belt doesn't change.
On the other hand, if you choose a tool that doesn't remain in a fixed position, such as a hand sander, then secure the blade in a vice so it doesn't move during sharpening.
The second step to sharpening wood chipper blades is to select sandpaper or a grinding wheel with very fine grit.
As you sharpen a blade, one of your main goals should be to remove as little material at a time as possible, which is hard to accomplish with a low grit and coarse sandpaper. A higher grit, or very fine sandpaper, allows for more surgical removal of material at a time.
PRO TIP: Try to use at least a 400-grit or 1000-grit when sharpening your wood chipper blades.
The third step is to start sharpening the blades but try to remove as little material as possible at a time.
Blade Sharpening Tips
We cannot stress enough how important it is to only remove a little material at a time. If you remove too much at a time, the blade can overheat and lose its heat treatment, permanently ruining it. The sharpening process is not a race so take it slow.
The fourth step is to remove any burr on the backside of the blade edge that was created during the sharpening process.
Burr is a by-product of sharpening and must be removed for high-performance chipping. If you skip this step and don't remove the burr, it can cause increased friction and premature dullness.
To remove the burr, we recommend using a whetstone. It should only take a few minutes and is worth the effort. If you don't have access to a whetstone, then one alternative is to use a finer grit sandpaper. For example, if you used 600-grit to sharpen the blade, then try using 1000-grit to remove the burr.
PRO TIP: You can use your finger to feel the burr on the backside of the blade edge. Just be careful not to cut yourself.
The fifth step to sharpening wood chipper involves balancing the blades if you have a chipper with more than one blade.
A flywheel in a wood chipper can rotate at several thousand rotations per minute (RPM). If your wood chipper has two blades and they are unbalanced, this can lead to stress on the blade shaft, vibration, and even damage to your engine.
The blades on a new wood chipper weigh the same and are therefore balanced. As you sharpen the blades and remove material, they no longer weigh the same and are therefore out of balance.
The best way to balance wood chipper blades is to weigh each of them using a scale that is accurate in grams. Take the one that weighs more and remove a little more material at a time and then weigh it again. Continue this process until both blades have the same weight.
PRO TIP: If your blades are not reversible, then remove material from the bottom to quickly balance without having to subsequently remove burr.
Here are some answers to additional questions people ask about wood chipper blades and some tips on replacement.
The manufacturer of your wood chipper may have specified certain torque amounts for the bolts that attach the blade to the flywheel. Check your wood chipper's manual for any torque specifications. Make sure to use a properly calibrated torque wrench when you torque each bolt.
The general rule of thumb is to sharpen wood chipper blades every 25 to 50 hours of usage. However, you may have to sharpen your blades earlier if one of the conditions in the list below exist.
Reasons to Sharpen Wood Chipper Blades Earlier
A single-sided wood chipper blade can usually last 25 to 50 hours between sharpening and can be sharpened a total of 3 times, bringing its total lifespan to 75 to 150 hours.
A double-sided wood chipper blade has double the lifespan of a single-sided blade and can usually last between 150 to 300 hours.
Factors that Affect Blade Lifespan
An often overlooked question when buying a wood chipper is whether the manufacturer sells replacement blades. In some instances, the company may not offer replacements and this could leave you with a broken chipper.
Another buying consideration is if you're looking to purchase a shredder or a wood chipper with a shredding feature. In most instances, shredding hammers cannot be sharpened. So are the hammers replaceable or are they riveted into the flywheel? Does the manufacturer sell replacement hammers? Will they be in business when you need them?