Toro GR 105 Fundamentals page 20

18
Sharpening Methods
• Maintain proper ADJUSTMENT
• BACKLAP the bedknife and reel
• GRIND the reel and bedknife
Fundamentals of Reel Mowers
Reel blades, and the edge of the bedknife
should be checked for damage visually and by
carefully feeling the edges. Of course, this
should only be done when it is certain that the
reel cannot be started, and never slide your
fingers down the edges lengthwise.
Rounded edges on the reel blades and
bedknife will cause the grass blades to be
pinched and torn, rather than sheared off
cleanly. When light contact is not maintained,
dull edges will soon result.
Sharpening will also be required if the reel is
"cone shaped" (tapered). All reels eventually
become tapered with use. If the reel is not
adjusted or ground to a cylinder shape again, a
mismatch in the height cut between adjacent
reels can result.
There are several methods that may be used
to sharpen a cutting unit. The one that you
choose will depend upon the condition of the
cutting unit. It should also make the most
sense for the anticipated use. For example, if
you are about to mow greens that have been
core aerated or topdressed, you may not want
to grind the reels and install new bedknives.
As the reel blades run against the bedknife a
slight burr will appear at the front cutting edge
surface the full length of the bedknife.
Occasionally run a file or facing grinder across
the front edge to remove this burr to extend
the cutting performance of the machine.
Lapping must be done after single blade
grinding. This is done to establish a "land area"
and to insure a perfect match between the
bedknife and the reel edge.
Lapping is not intended to be a reconditioning
process to correct severely nicked or rounded
blades, rifling or taper. If, after 5 minutes of
lapping, the edge is not restored, it is time to
grind the reel.
TORO® Service Training