Bush Hog PT5 manual Sharpening the Knife

MAINTENANCE

MAINTENANCE

Sharpening the Knife

After five to twenty operating hours, depending on the work involved the knives require re-sharpening. It is recommended that knives are removed from the cutterbar for re-sharpening.

Switch off tractor, disconnect the con rod, remove the three setscrews securing the knife heel to the knife and withdraw the knife from the cutterbar.

Clean the knife and ensure that neither the back nor the knife sections are bent. Straighten as necessary. A cutting angle of 35-40 degrees is required.

A high speed hand grinder should be used with ideally, a pot shaped pencil grinder of approximately 25 MM (1”) dia by 35 MM (13/8) long. Grinding is carried out with the end face of the grinder moving from the base of the knife section to the points.

It is possible to re-sharpen the knives in place. Position the cutterbar on or parallel to the ground. Switch off the tractor engine and disconnect the con-rod. Manually position the knives so that they cover the fingers and clamp together in this position.

Sharpening with files is not recommended as the process tends to leave small burrs on the edge which when the knife is replaced, will curl under impeding the free movement of the knife and leave a blunt cutting edge.

PT5 09/10 Maintenance Section 5-4

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