John Deere
GOLF
& TURF
Training Department

Four Principle Angle
Clearance Necessary
Relief Angle
Milled Relief Blades
Rake Angle
Bedknife Angles
Parallel Edges
Coned Shaped Reel
Dulling Curve
Dull Edges
(Left Click Selection Box)
Backlapping
Total Cost of Mowing
HOC
Bench Setting
Effective Height of Cut
Prism Gauge
FOC
Bedknife Attitude
Reel/Bed Relationship

Reel Cutting Unit

Clearance Necessary

.002” or .001”
Clearance

4. Top
Angle
Four Principle Angles
1. Relief
Angle
2. Rake
Angle
3. Front Angle

Reel Blade Relief Angle
.040”
(1 mm)
20 Degree
Relief Angle

Different Types of Relief
Ground
Relief
Milled
Relief

Reel Load Comparison
Reel-Bedknife Clearance
.002
” .005” Touch
 Relief Ground / Sharp Bedknife (HP per unit) .75 .74 .88
 No Relief / Sharp Bedknife (HP per unit) .87 .87 2.59
 % Increase in HP Consumed ( per unit ) 16% 17.5% 294%
 Increase in HP Consumed per 3235 (5 units) 0.6 hp 0.65 hp 8.55 hp
* Tests Conducted While Mowing 1.5” Bermuda to 1.0” HOC

Rake Angle
Rake Angle

Bedknife Angles
Top Angle
Top Angle 5 Degrees (6.5 Greens Mower)
Front Angle 5 Degrees
Front
Angle

Cutting Edges
Must Be Parallel
 The Reel Must
Be Perfectly
Straight and the
Bedknife Must be Straight and
Flat in Order for
Them to Work
Properly
Reel
Bedknife

Cone Shaped Reel
 Reels Can
Become Cone-
Shaped. This
Causes a Great
Deal of Strain on the Supporting
Bearings When
Adjusted Parallel to the Bedknife
Reel
Bedknife

Dull Edges
Edges Have
Become
Rounded…
No Longer a Sharp
Edge

Backlapping
Backlapping
Compound with Reel
Turning in
Reverse
Direction

Cutting Unit Dulling Curve
Sharp
Optimum
Cutting
Quality
Usable
Cutting
Quality
Dull
Elapse Time in Hours

Backlapping Retains
Optimum Cutting Quality
Sharp
Optimum
Cutting
Quality
Usable
Cutting
Quality
Dull
Elapse Time in Hours

Height of Cut (HOC)
 Two Methods of Measuring HOC
 Bench Setting
 The Height at Which the Bedknife is Set Above a Firm Level Surface
 Effective Cutting Height
 The Actual Height at Which Grasses Are Cut

Bench Setting
 Distance Between
Top of Bedknife and Bottom of
Rollers

Effective Height of Cut
 Weight of the Cutting Unit and Attachments
 Every 10 lbs results in .005” height difference
 Soil Conditions
 Roller Shape and
Surface Area
 Grass Type

Frequency Of Cut (FOC)
 Distance Traveled Between
Consecutive Cuts
Direction of Travel

FOC Factors
 Number of Blades on Reel
 Reel Speed (RPM)
 Travel Speed

FOC Negative Effects
 FOC Too Slow (Higher Number)
 Marcelling (Wash Boarding)
(Rippled Effect)
 FOC Too Fast (Lower Number)
 Over Stressed Grass
 Stripes and/or Brown Tips
 Accelerated Component Wear

Marcelling
 Wash-boarding
 Rippling
Objectionable
Cut Quality

FOC “Guideline”
 The Lower the Height of Cut (HOC)
The More Blades That Are Required
 The Higher the HOC
The Less Blades That Are Required

Bedknife Attitude
 Down
 Level
 Better Cut Quality
 Better Stripe
 Reduces Scuffing
 Accurate Height of Cut Adjustment

Reel / Bedknife Relationship
 ESP Cutting Unit
(Parallel Bedknife)
.78 MM
11.76 MM
48

Reel / Bedknife Relationship
 ESP Cutting Unit
(Bedknife Angled Down 6MM)
1.02 MM
13.43 MM
51

All Greases Are NOT
Created Equal
Bushing and
Shaft
 Different Applications Require Greases with Characteristics that Meet Their Requirements