How Reel Mowers Work

Reel Mower Parts

How Stufff Works

Manual reel mowers are reasonably simple devices; they depend on just a few moving parts and the basic application of force. The mower's overall construction is that of a small cart with a long handle. Most reel mowers feature two primary wheels on a single axle with either a bar of rollers or a set of smaller, secondary wheels in the rear. The rear roller or rear wheels simply provide balance, while the primary wheels provide the motion needed to turn the mower's bladed cylinder.

The best way to understand how reel mower parts work is to follow the flow of force through the mower.

  1. A person pushes on the handlebars, applying force.
  2. The applied force moves down the handle, pushing the mower forward on its wheels.
  3. As the axle turns, it sends a pair of gears spinning. The first gear has a larger diameter than the smaller pinion gear. When a larger gear passes its rotation force, or torque, onto a smaller gear, the torque increases. This is why the blades of a reel mower turn much faster than the wheels. For more information on the physics of this, read How Gear Ratios Work.

The brush bar on the front of the mower bends tall grass, folding it over into the spinning cylinder blades. The spinning reel may look impressive, but it doesn't actually cut the grass on its own. All the cutting of the grass takes place where the spinning edges meet the stationary cutter bar in the rear of the mower. Think of it as the point of contact between the two blades of a pair of scissors. The cylinder scoops up the grass and moves it to the cutter bar the same way a barber uses a comb to position hair for snipping.

Most of the grass clippings then fall behind the mower, allowing for the use of a collection tray or bag on many models. Reel mowers differ drastically from rotary mowers in this respect, as the latter's fan-like blades actually tear grass, which can more easily expose the plants to disease [source: University of Tennessee].

Sound like a great addition to your tool shed? Turn to the next page to learn how to use and maintain a reel mower.