Easy Mower Blade Balance Tool

Mower blades need to be sharpened. Wear patterns are not always the same on both ends of the blade. One end of the blade can easily become heavier than the other. A blade out of balance can make unpleasant vibrations, and can also cause premature wear on engine bearings. Pictured is a simple wire device easy to make that can help you do a very good job balancing a mower blade after sharpening.

A number of blade balancing devices are available. Some mount on the wall and are equipped with ball bearings with a price in excess of $100.

You will need a piece of wire. The piece I used is 16 gauge steel wire. I cut it about four inches long. Make it as straight as possible.

For tools you will need a steel rod 1/4 inch in diameter. It does not need to be more than a couple of inches long. A vise is advised. Also have a pair of pliers with a wire cutter. A drill bit about 3/8 inch in diameter makes a good measuring device.

Mark the center of the wire's length. Bend it over a 1/4 inch rod to make about a 45 degree angle.

When you bent the wire in the previous step, it may be that one end is slightly longer than the other. Measure and trim the longer end so it is the same length as the shorter end.

Place the bent wire between the jaws of a vise so the ends extend upward beyond the top of the vise jaws about 1/4 to 3/8 inch. It helps a lot if the vise jaws are aligned well and at the same height. Make the vise jaws almost tight, but not quite. You want the amount of wire extending above the jaws to be equal on both ends. I used the solid end of a drill bit as a gauge. I was able either to pull a little wire up with the jaws of a pair of pliers, or to tap a wire end farther down into the vise with a hammer. After adjusting one end of the wire, check the other end to be certain it has not moved. Tighten the vise jaws so the wire cannot move after the ends are aligned.

Bend the wire ends over on the jaws. Make one bend toward the front of the vise and the other toward the back of the vise. This will help to keep the mower blade more stable when balancing it. The needle nose pliers were used to adjust the bends so they are at a right angle to the opening in the jaws.

I prefer to clean build-ups of dried grass from the blade before balancing it. Use a wire brush or a putty knife.

The photo shows the shape of the opening for mounting the mower blade on the engine shaft. I place my bent wire balancer into the opening from the bottom so the corner of the bend will be above the top of the blade. Pull the bent wire balancer so the wire balancer is in as far as it can go.

Place a nail through the bent peak of the wire balancer. Hook two fingers to cradle the nail. Pick the blade and balancer up Take note to see if the blade is level, or if one end dips appreciably. I watched some videos of people using the new ball bearing balancers. I was surprised how much dipping was allowed to count a mower blade to be in balance. I like my blades to be as close to level as possible. If you want to check your work, give the wire balancer tool a half turn and see if the blade rests in the same place when suspended.