Reel Technology and Setup Flashcards

A technician observes a distinct 'washboard' or 'marcelling' pattern on a turf surface after mowing. This issue is most commonly caused by the relationship between the height of cut (HOC) and which other operational setting?

Answer: Frequency of clip (FOC) being greater than the HOC

Marcelling, or a washboard pattern, occurs when the distance the mower travels between successive clips (Frequency of Clip) is significantly greater than the height of cut. This creates a visible wave pattern on the turf. To fix this, the FOC must be made smaller, typically by increasing reel speed or decreasing ground speed.

What is the primary purpose of applying an abrasive backlapping compound to a reel and bedknife assembly?

Answer: To hone and mate the cutting edges of the reel and bedknife

Backlapping is a maintenance procedure that uses an abrasive paste to sharpen the reel and bedknife. By spinning the reel in reverse, the compound lightly hones both cutting surfaces, creating a perfectly matched, sharp edge between them. It is used for maintaining a sharp edge between grindings, not for heavy material removal or initial setup.

A technician is performing a 'relief grind' on a cutting reel. Which of the following best describes the goal of this procedure?

Answer: To reduce the contact area of the trailing edge of the reel blade

A relief grind removes material from the back, or trailing edge, of each reel blade. This reduces the surface area (the 'land') that makes contact with the bedknife, which in turn reduces friction, lowers the horsepower required to turn the reel, and helps the unit stay on-cut longer.

When performing a bench setting for the Height of Cut (HOC) on a reel mower, the measurement should be taken from a flat surface plate to the:

Answer: Top front edge of the bedknife

The Height of Cut is determined by the vertical distance between the bottom of the rollers (representing the ground plane) and the cutting edge of the bedknife. Therefore, when using a gauge on a flat surface, the measurement is taken from the surface plate to the top, front cutting edge of the bedknife.

A technician is setting the reel-to-bedknife adjustment. After achieving a clean cut on a single sheet of paper across the full width of the reel, they notice the reel is very difficult to turn by hand and makes a heavy grinding sound. What is the most likely issue?

Answer: The reel-to-bedknife contact is too tight.

The goal is to achieve a clean cut with the lightest possible contact between the reel and bedknife. Excessive contact, even if it cuts paper, creates unnecessary friction, heat, and rapid wear on both the reel and bedknife. The reel should spin relatively freely after adjustment.

The term 'Frequency of Clip' (FOC) is calculated using which three variables?

Answer: Reel speed (RPM), number of blades, and ground speed

Frequency of Clip (FOC) is the distance the mower travels forward between each cut. It is a function of how fast the mower is moving (ground speed), how many cutting edges are on the reel (number of blades), and how fast those blades are rotating (reel RPM).