Ask the Mechanic

Just Won't Cut It

(Getty Images, Photo Illustration by Barry Falkner)

READER: I traded my old sickle mower for a brand-new (expensive) side disc cutter that has a tarp on it. I have done everything I know to make it cut clean like my sickle mower. I have run it fast, slow, medium -- still will not cut clean. The dealer told me that my cut was normal. I do like to cut my hay a little taller than most of my neighbors; it seems to recover faster after it is cut a little high. What can I do to make this cutter cut clean like my old sickle mower?

STEVE: Your new disc cutter will never cut near as clean as your sickle, but it cuts relatively clean only if it has a solid stem to cut. The disc cutter cuts with an impact cut, and a sickle mower cuts with a shear cut. This means that the disc mower needs to cut as low to the ground as needed to find a solid stem. As a result, sometimes the disc mower will knock down some of the crop if it does not find a solid stem. There is no "backup" for the crop with an impact cut. The shear plates on the guards of a sickle mower serve as a "backup" to hold the grass while the sickle section shears the crop with a shear cut, similar to scissors. If your crop gets tall and falls down, there is nothing that will cut as clean as a sickle cutter with a finger reel up-front that stands up the down crop. I keep one on my farm just for down crops.


-- Write Steve Thompson at Ask The Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email, and be sure to include your phone number.


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