Hedge Trimmer: Blade Cuts Poorly

Your hedge trimmer’s blades are designed to cut and trim brush. To accomplish this, the blades move back and forth in a reciprocating motion. As you use the trimmer, pieces of debris such as sticks and twigs can prevent blade movement and even cause the blades to break. If you notice the branches you’re working on are being cut unevenly or are frayed, this is an sign that the blades need to be sharpened. Sharpening the blades may solve this issue without having to replace any parts. Another issue that you may encounter is bent teeth on your trimmer’s blades. You can easily fix this issue by loosening the bolts on the blade guide and bending the teeth with pliers. If you require blade replacement then remove all the locking nuts securing the blades and remove the blade guard and tip guard with the washers. Next remove the gear case cover, and remove all the blade mounting bolts with washers. Then, remove the lower gear and carefully remove the lower blade, spacer plate and the top blade. Now you’re ready to install new blades. To begin, position the inner gear so the holes are in line with the blade support. Be sure to add a little white grease between all these moving parts during re-assembly. Next, align the top blade with the sharp edge facing away from the blade support and re-install the spacer plate. Install the lower blade with the sharp edge facing away from the blade guide. Re-install the lower gear with the cam aligned on the opposite side of the inner gear cam. Make sure the holes in the gear are in proper alignment with the blades. Adjust the lower blade until the gear sets into place. Reinstall the felt seal, new gasket, and cover, and re-install the trimmer blades back into the blade support. Finally, realign the blade guards on to the mounting bolts and use new locking nuts to secure the bolts.

Hedge trimmers are equipped with gears that rotate with one another, allowing the blades to move back and forth. If gears are broken or have worn teeth they will not rotate properly, and this will result in blades that cut poorly. If you notice your gears are damaged or the teeth are worn or broken, you will need to replace them before this symptom is resolved. To do so, first remove all the locking nuts securing the blades and remove the blade guard and tip guard with their washers. Next, remove the gear case cover and remove all the blade mounting bolts and washers. Then, you will need to remove the felt seal and remove the lower gear. At this point, carefully remove the lower blade, spacer plate, and the upper blade and upper gear. Replace the top gear and keep the hole in line with the blade support. Align the top blade with the sharp edge facing away from the blade support, and reinstall the spacer plate and lower blade with the sharp edge facing away from blade guide. Re-install the lower gear with the cam aligned on the opposite side of the inner gear cam. Be sure to check that the holes in the middle of the gears are in proper alignment with the blades. Next you will have to adjust the lower gear until it sets into place. At this point you can re-install the felt seal, new gasket, and cover. Now you can reinstall the trimmer blades back into the blade support and re-align the blade guards on to the mounting bolts. Use new locking nuts to secure the bolts as locking nuts are a onetime use.

The purpose of the blade guard is to prevent entry of improper or oversized debris from entering the blade teeth, causing damage. If your trimmer’s blade teeth are damaged, you may be able to solve the issue by bending them back into position with a pair of pliers. However, if the blade itself is damaged you will likely need to replace it entirely. Similarly, if the guard on your trimmer is broken or damage it must be replaced, so that it can continue to protect the blades from damage. To replace the damaged guard, simply loosen the locking bolts on the blade guard and tip, and simply pull it off and replace it with the new guard.