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LSMP - October 06 - Close Up - Mower Maintenance: 10 Steps to Better Blade Sharpening09-29-06 | News

Mower Maintenance: 10 Steps to Better Blade Sharpening

When buying rotary mower blades, look for those that have been designed to perform for specific mowers, such as this Wright Velke walk-behind.

What would an annual mower issue be without a look at some mower maintenance? With your crew cutting acres of turf on a daily basis, choosing the right mower for the application, coupled with the right cutting unit can make a huge difference. However, consistent service can keep you on schedule and under budget. Below is an overview of the commercial rotary mower and, more importantly, how to care for its blades.

Rotary mowing systems are the most common in the landscaping industry and have the broadest applications. When buying rotary mower blades, one of the most important things to remember is to look for those that have been designed to perform for the specific mower in question. Using blades in an application that they were not specifically designed for may actually decrease mowing effectiveness or even be unsafe.

Rotary mower blades can be divided into two broad categories ?EUR??,,????'??? side- or rear-discharge and mulching. However, the primary function of most rotary decks is side discharge. The blades on these decks have a more aggressive wing and higher airlift so they propel grass out the side discharge chute more efficiently and disperse the clippings more evenly.

Mulching blades typically have a downdraft feature inboard from the airlift that directs materials back into the turf. Blades with short notches in the airlift portion cause more shredding of the cut grass but generally do not improve cut quality or dispersion.

We can show you the newest and biggest mowers on the market but if you don?EUR??,,????'???t keep them serviced ?EUR??,,????'??? more specifically their blades sharpened ?EUR??,,????'??? they are just a pile of metal and bolts out of commission in the garage.

Sharpened blades, like this Oregon Fusion Blade, require less power, give a cleaner cut and do not fray the end of the grass blade. Photos: pressroom.oregonchain.com/photos.htm

If you perform regular blade sharpening you will keep your mowers in the field every day and prevent disease and sun damage to your turf.

Here?EUR??,,????'???s The Point

Blade sharpness is the essential element of mower blade maintenance. Many people don?EUR??,,????'???t realize that dull mower blades actually tear grass rather than cut it, leaving the grass exposed to disease and unsightly brown spots, and affect your bottom line in the cost of wasted fuel. Sharp blades require less power, give a cleaner cut and do not fray the end of the grass blade.

Mowing conditions and hourly use determine when to sharpen blades. Generally, if blades are cutting lush, thick lawn areas, they may only need to be checked once during the middle of the season. If the mower is being used on an all-day, everyday basis, the blades should be checked every 25 to 30 hours. If the blades are cutting in areas with sandy soil conditions, the blades should be checked more often.

Most manufacturers recommend that certified technicians sharpen mower blades. However, if you do this yourself, you can use a grinder, hand file or electric blade sharpener. Also, no matter the blade type, it?EUR??,,????'???s important to remember to handle blades carefully with gloves at all times, to help prevent injury. The steps below will guide you through routine sharpening, so you can keep your ride-on mowers running at full throttle every day.

First remove the spark plug wire to ensure the lawn mower doesn?EUR??,,????'???t start up accidentally. When you perform routine sharpening follow the steps below, and your ride-on mowers will be running in tip-top shape.
To check for a bent blade, lower the mower on a flat surface and measure the distance between one end of the blade tip and the ground. Turn the blade 180 degrees and measure the distance between the blade?EUR??,,????'???s other tip and the ground. If the distance between the two measurements is more than 3mm (1/8 inch), it is time to install a new blade. (A blade should be replaced when it is either bent or is substantially worn from either resharpening or sandblasting. When operating in areas that have sandy soil, the airlift portion of the blade may wear away more rapidly as the sand erodes the blade material even though there may still be material left for sharpening the cutting edge.)
Once you have access to the under side of the mower deck and have decided the blade is worth keeping, scrape out any built-up dirt and debris.
Remove the bolt from the center of the blade and clamp it in a bench vise once you have detached it from the mower.
Using a grinder, hand file or electric blade sharpener, remove any small nicks from the blade edges.
Sharpen the blade by filing a uniform edge to ensure a clean, even cut. Follow the original bevel of the blade as closely as you can, (the angle will be roughly 45 degrees).
Make an equal number of strokes on each edge. If too much metal is taken off of one side, the blade will be out of balance and will cut unevenly.
After sharpening and during reinstallation, it?EUR??,,????'???s important to remember to properly balance the blade. An unbalanced blade causes vibrations and movement in the deck that can lead to premature part failure and possibly unsafe mowing conditions. A balanced blade helps to ensure even cut quality, lower sound levels and increased operator comfort.
To balance, place the blade on a nail in a vice or vertical wall stud. Turn the blade to a horizontal position. If the blade remains horizontal, the blade is balanced. If one end drops, grind the bevel of the heavy side and rebalance. Repeat the process as necessary until the blade is balanced.
Reinstall the blade, then tighten the mounting bolts and any lock washers securely.

Blades like this Oregon Gator Mulcher Duplex has a downdraft feature inboard from the airlift that directs materials back into the turf. The short notches in the airlift portion cause more shredding of the cut grass.

Damaged or bent blades are inevitable for any mower deck. However, if you keep the factory-installed chute guards intact and in the proper position, and avoid mowing areas with hidden obstacles that can damage the blades, you can do a lot to prevent major problems. More importantly, if you perform regular blade sharpening you will keep your machines in the field every day and improve the overall look of the grass you work so hard to maintain.