Toro GR 105 User manual

Commercial Products
Fundamentals of
Reel Mowers
PART NO. 98008SL, Rev. B

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Fundamentals of Reel Mowers 1
TOROService Training
Table of Contents
Historical Background .....................................................................................................2
Theory of Operation........................................................................................................4
Importance of the Operator.............................................................................................8
Preventive Maintenance..................................................................................................9
Set-up and Adjustments................................................................................................ 11
Sharpening....................................................................................................................17

2Fundamentals of Reel Mowers
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Historical Background
The concept of the reel mower goes back to
the 1800’s. It evolved out of a need for
groomed turf areas being maintained on a
regular basis.
Golf course development during the 1920’s
and 30’s brought about design improvements
in engines and mower drive systems.
These improvements continued, allowing for
lighter weight and easier to use equipment.

Fundamentals of Reel Mowers 3
TOROService Training
The development of hydraulics during the 50's
and 60's improved the reliability, safety,
operator comfort and lowered maintenance
costs.
Although dramatic improvements have been
made in reel type mowers, some of the same
frustrations that developed working with reel
cutting units years ago are still present today.
If reel mowers unique characteristics are not
understood and responded to, the end result
will be a poor quality of cut and expensive
down time and repairs.

4Fundamentals of Reel Mowers
TOROService Training
Theory of Operation
There are three main structural members in a
reel cutting unit:
The REEL consists of varying numbers of helix
shaped blades attached to support spiders
which are mounted on a rotating shaft.
The BEDKNIFE is attached to the bedbar and
the assembly is mounted to the main frame in
a manner that allows for paralleling and
adjustment to the reel.
The FRAME supports the rollers, the bedbar
assembly and reel with it’s drive mechanism,
which can be hydraulic, belt driven or ground
driven.
A reel mower cuts grass with a scissors-like
shearing action as the moving helix shaped
blades pass over the stationary bedknife. The
cutting action requires that the bedknife and
reel blades be sharp, matched, and in close
relationship with each other.
When properly maintained and operated, reel
mowers provide superior quality of cut. It
cannot be overstated that reel mowers are
precision tools. It is essential that they be
adjusted and operated with this in mind.
Reel Mower Clip
To understand reel cutting theory, you must understand the concept of clip and the shear point. A shear
point is any single point of contact made between the reel blade and bedknife.
Clip is the forward distance traveled between
successive blade contacts at one shear point.

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TOROService Training
Factors Affecting Clip
•The diameter of the reel
•The number of reel blades
•The speed of the reel
•The ground speed.
By following the blade path through two “clips”
as the machine moves forward we can
illustrate the actual process of cutting grass.
The bedknife pushes grass toward the shear
point while the reel blade gathers it in front.
Each blade path has one-half clip in which to
cut all the grass
Note that the grass outside of the forward half
clip is not easily gathered. The general rule of
thumb concerning height of cut vs. clip is that
both measurements should be within 20% of
each other. The best results will be obtained
when height of cut is equal to or close to the
clip.
Grass extending beyond the forward half clip,
yet tall enough to be within the blade path is
less likely to be cut. Reel blades may contact
the grass in this area several times prior to the
actual gathering of the grass. This is the so
called “fanning” process. This process is more
a mechanical striking of the grass that it is of
the commonly thought effect of a blowing
action.

6Fundamentals of Reel Mowers
TOROService Training
This is an extreme case corrugation. Because
of an imbalance between height of cut and
clip, the grass is cut with extreme valleys and
peaks.
NOTE: If you change equipment or height of
cut you may notice some corrugation after the
first mowing. This will go away after the grass
is maintained at the new height of cut over a
period of time.
The importance of the bedknife front angle is
visible from the side view. Note that the proper
angle allows the grass behind the bedknife
front edge to be more effectively cut.
A front view illustrates the angle between the
bedknife and the reel blade which is called the
helix angle.

Fundamentals of Reel Mowers 7
TOROService Training
Another term known as “the cutting path” is the
result of the helix angle and the forward motion
of the cutting unit. The shear point moves
down the bedknife as the bedknife moves
forward. The grass is physically cut at an angle
to the bedknife.
Cross section of turf cut at various heights
1/2” 1” 1-1/2” 2”
Other factors which affect reel mowing are the
grass density and the grass acclimation or
grain. Grass tends to thicken at the normal
maintained height of cut. The denser the
grass, the easier it is for the bedknife and reel
to gather it. Grass density and grain can often
override other factors we have discussed
regarding the cutting action.
The basic requirements for good performance
of reel mowers are:
•The cutting edges on the reel blades
and bedknife must be straight and
sharp.
•The bedknife must be exactly parallel
with the reel.
•The bedknife should be positioned
against the reel with light contact.
These requirements will be discussed in more
detail later.

8Fundamentals of Reel Mowers
TOROService Training
Importance of the Operator
The Operator has a significant influence on the quality of cut that a reel mower can deliver.
The large investment in specialized mowing
equipment cannot be jeopardized by
unqualified operators. Before an operator can
be considered qualified to operate a piece of
equipment, there should be a significant effort
by the supervisor towards their training and
familiarization with each piece of equipment.
Make sure the operator reads and
understands the Operator’s Manual. Have the
operator watch the Operator Training Video,
then explain any unique methods or
procedures used on your grounds.
A supervisor should play a key role in
establishing the proper attitude and behavior
patterns toward operating turf equipment. A
supervisor should not create the impression
that a few minutes orientation on a piece of
equipment will qualify the operator.
Operators and service technicians play a
significant role in determining quality of cut,
down time, and life of mowing equipment.
Make a commitment to train and familiarize
staff with each product. Remember, that each
type of mowing equipment will have specific
operating characteristics, and noise qualities.
Operators should become familiar with the
product and listen for any unusual changes.
Concerns should be reported to the service
technician before significant problems develop.