Understanding the Role of Bed knives

PublishTime: 2019-08-26 08:32:37

Michael Hampton, explains the important role bed knives play in the fine finish expected from a cylinder mower. “Along with the cylinder and the frame, the bed knife is one of the three main structural members in a cylinder cutting unit. The bed knife is attached to the bed bar and the assembly is mounted to the main frame in a manner that allows for paralleling and adjustment to the cylinder.

“A cylinder mower cuts grass with a scissor-like shearing action as the moving helix-shaped blades pass over the stationary bed knife. The cutting action requires the bed knife and cylinder blades to be sharp, matched and in close relationship with each other, and the bed knife sharpened to be flat and square so the sharp edge touches the cylinder blades across their entire length.
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“If the bed knife is not perfectly flat, it is impossible to get the bed knife to touch the entire length of the cylinder. This is an essential part of the construction, making cylinder mowers precision cutting tools. Adjust any part of the construction process with, for example, ‘will-fit’ parts and the fit, form and function can be affected to leave a less attractive and less consistent after-cut appearance.

“To understand the cylinder cutting theory fully, you need to understand the concept of the clip and shear point. A shear point is any single point of contact made between the cylinder blade and bed knife. The clip is the forward distance travelled between successive blade contacts at one shear point. As the cylinder moves forward it pushes the grass in front of it, while the cylinder blade gathers the grass as it moves toward the bed knife. The bed knife then pushes the grass toward the shear point, while the cylinder blade gathers it in front, creating a triangle.”
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Hampton concludes: “The fine finish expected from a cylinder mower is not down to luck, far from it. Understanding and appreciating that cylinder mowers are precision machines, requiring precision-engineered parts in order to achieve the best possible finish should help make the decision that ‘will-fit’ parts aren’t worth the negative impact on the turf.

A true flatness of the knife extends their life and maximizes the quality of cut. They’re made of high carbon steel for ultimate durability and longevity, and to retain their edge for longer, meaning greenkeepers can mow longer without the need to adjust or replace as frequently.

If you are interested in this type of product, please contact us----Maanshan Green Friend machine Manufacturing Co., Ltd.