Blade Shaft Assembly

Blade Shaft Assembly

How to Sharpen Your Reel Lawn Mower – Part Two: Sharpening the Blades

Once you have determined that your blades do need sharpening, there are several way you can accomplish this. Whichever method you choose will depend on your personal preference. If you have lots of good arm strength and your mower is pretty clean go with the One Wheel Off Method. If your mower is dirty, use the Two Wheels Off Method so you can clean the parts and re-grease the reel shaft. If you aren't physically very strong, you may wish to try the Push Sharpening Method. And finally, if you have drill and socket bit set you may wish to give the Drill Bit Method a go.

One Wheel Off Method

If you have chosen to remove just one wheel, keep the pawl in place. You may wish to flip the mower over to its upright position or you can continue with it upside down, or even on its side. I prefer to flip is over to right-side up as it makes more sense to me.

Fit the sharpening crank over the shaft and pawl. Insert one of your pieces of paper between the blade and the knife blade at one end of the reel and turn the crank so the reel is moving forward, the same way it would be moving if you were mowing the lawn. You will want to continue the turning until all of the blades have had a chance to pass over the piece of paper so you can see if they are all cutting the paper smoothly. Repeat with more pieces of paper in the middle of the reel and then again on the opposite side that you started from. If the blades are not cutting the paper cleanly and easily all the way around then they need sharpening.

Apply the lapping compound to the cutting edges of the blades. Apply sparingly or it tends to run off the cutting edge, but ensure all cutting surfaces are well covered. Apply to all blades, turning the crank to turn the reel as needed to expose all of the blade. This time you will be turning the reel backwards, or the opposite way from the way it would turn if you were mowing.

Once all the cutting surfaces have been covered with lapping compound, turn the crank to turn the reel backwards for about 7-8 minutes. In some cases, the lapping compound will begin to change colour. You want to see that the cutting edge is bright and shiny with a smooth edge. This is hard work! Take breaks, Tom Sawyer your children into helping, or try using a drill bit (more below) to turn the reel.

Once you think the blades are sharp, repeat the paper test to ensure all cutting surfaces are sharp. If the paper is cut cleanly and easily then you are finished. Adjust the blades if needed.

Replace the gear, the wheel, the E ring (this will be harder to get back in than it was to pry off) and the side cover.

Two Wheels Off Method

With the mower upside down, remove the wheel cover, E ring, gear and pawl from the second side. Keep the pawl in place on the first wheel. Flip the mower over so it is right side up. Clean out any dirt as needed.

Fit the sharpening crank over the shaft and pawl. Insert one of your pieces of paper between the blade and the knife blade at one end of the reel and turn the crank so the reel is moving forward, the same way it would be moving if you were mowing the lawn. You will want to continue the turning until all of the blades have had a chance to pass over the piece of paper so you can see if they are all cutting the paper smoothly.Repeat with more pieces of paper in the middle of the reel and then again on the opposite side that you started from. If the blades are not cutting the paper cleanly and easily all the way around then they need sharpening.

Apply the lapping compound to the cutting edges of the blades. Apply sparingly or it tends to run off the cutting edge, but ensure all cutting surfaces are covered. Apply to all blades, turning the crank to turn the reel as needed to expose all of the blade. This time you will be turning the reel backwards, or the opposite way from the way it would turn if you were mowing.

Once all the cutting surfaces have been covered with lapping compound, turn the crank to turn the reel backwards for about 7-8 minutes. In some cases, the lapping compound will begin to change colour. You want to see that the cutting edge is bright and shiny with a smooth edge. This is hard work! Take breaks, Tom Sawyer your children into helping, or try using a drill bit (more below) to turn the reel.

Once you think the blades are sharp, repeat the paper test to ensure all cutting surfaces are sharp. If the paper is cut cleanly and easily then you are finished.

Adjust the blades if needed. Replace the gear, the wheel, the E ring (this will be harder to get back in than it was to pry off) and the side cover for one wheel then repeat for the second wheel.

Push Method

This method initially seems more complicated, but once we experienced the hard work of arm sharpening, the ease of push sharpening seems to far outweigh the slightly longer disassembly and reassembly time.

With the mower upside down, remove the wheel cover, E ring, gear and pawl from the second side. Keep the pawl in place on the first wheel. Flip the mower over so it is right side up. Clean out any dirt as needed.Fit the sharpening crank over the shaft and pawl. Insert one of your pieces of paper between the blade and the knife blade at one end of the reel and turn the crank so the reel is moving forward, the same way it would be moving if you were mowing the lawn. You will want to continue the turning until all of the blades have had a chance to pass over the piece of paper so you can see if they are all cutting the paper smoothly.

Repeat with more pieces of paper in the middle of the reel and then again on the opposite side that you started from. If the blades are not cutting the paper cleanly and easily all the way around then they need sharpening.We have not tried this method ourselves but came across it while reading reviews. His suggestion "Remove both wheels , remove and switch ratchet gears from L to R and vice versa, flip over pawls, apply compound and push the mower backwards for about 5 minutes". From reading this we assume he means to put the left gear and pawl on the right side of the reel shaft and vice versa. We also assume that you would need to replace the wheels to push it backwards.

Once you think the blades are sharp, you would then need to disassemble the wheels, repeat the paper test to ensure all cutting surfaces are sharp. If the paper is cut cleanly and easily then you are finished. Adjust the blades if needed. Switch the gears and pawls back to their original sides and then replace the wheels. We will update you if we try this method to let you know how it works. I think that once it was done once, it wouldn't seem as confusing and would be a lot easier than cranking by hand.

Drill Bit Method

There were many mentions of turning the reel with a drill. You will need to find a socket attachment that fits over the reel shaft, a 16 or 17 mm socket size were mentioned most often. We would recommend removing the pawl as it might fly out while the drill is turning the shaft. Follow the instructions for disassembly as for the One or Two Wheel method. If you removed both gears, we recommend you remove both pawls. Fit the socket over the reel shaft and let the drill do the work for you. No one seems to mention how long to do this but we imagine it would take far less time than by hand. Visually check your blades for sharpness after 3 or 4 minutes. Re-assemble the wheel(s) as for other methods.

That's it! It may seem complicated at but after the first time you will be a pro! If you are not sure if your blades need to be sharpened please see Part One of our series,  How to Sharpen Your Reel Lawn Mower – Part One: When Should Your Blades Be Sharpened?

 

About the Author

Teresa is an avid, eco-conscious, gadget-loving gardener who herself owns two reel lawn mowers. Visit www.bestreellawnmowerreviews.com for reviews of the most popular makes and models based on owners' comments as well as field tests and editorial reviews.

how do you remove the nut from a lawn mower mandrel?

I must replace a worn mandrel shaft assembly, which attaches the blade to the pulley. Is the flanged, toplock nut threaded in reverse?

The nut comes off in the same direction as the blade turns - which is often right-handed (opposite standard lefty-loosey). This is so that they cannot come off during operation.

So, check the sharp edges of the blade - they are the 'leading edge' and so give you the direction it turns. If the unit has two counter-spinning blades, the nuts will turn opposite ways as well.