Reel Theory

GOLFTURF

Training Department

&

John Deere

Four Principle Angle

Relief Angle

Milled Relief Blades

Rake Angle

Bedknife Angles

Parallel Edges

Clearance Necessary

Coned Shaped Reel

Dulling Curve

Dull Edges

Backlapping

Total Cost of Mowing

HOC

Bench Setting

Effective Height of Cut

Prism Gauge

FOC

Bedknife Attitude

Reel/Bed Relationship

(Left Click Selection Box)

Reel Cutting UnitReel Cutting Unit

Clearance NecessaryClearance Necessary .002” or .001”

Clearance

Four Principle AnglesFour Principle Angles

1. Relief Angle

3. Front Angle

4. Top Angle 2. Rake

Angle

Reel Blade Relief AngleReel Blade Relief Angle

20 Degree Relief Angle

.040” (1 mm)

Different Types of ReliefDifferent Types of Relief

Milled

Relief

Ground

Relief

Reel Load Comparison

Relief Ground / Sharp Bedknife (HP per unit)

No Relief / Sharp Bedknife (HP per unit)

% Increase in HP Consumed ( per unit )

Increase in HP Consumed per 3235 (5 units)

.002” .005” Touch

.75 .74 .88

.87 .87 2.59

16% 17.5% 294%

0.6 hp 0.65 hp 8.55 hp

* Tests Conducted While Mowing 1.5” Bermuda to 1.0” HOC

Reel-Bedknife Clearance

Rake AngleRake Angle

Rake Angle

Bedknife AnglesBedknife Angles

Front Angle

Top AngleTop Angle 5 Degrees (6.5 Greens Mower)

Front Angle 5 Degrees

Cutting Edges Must Be ParallelCutting 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 ReelCone 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 EdgesDull Edges

Edges Have Become Rounded…

No Longer a Sharp Edge

BacklappingBacklapping

Backlapping Compound with Reel Turning in Reverse Direction

Cutting Unit Dulling CurveCutting Unit Dulling Curve

Sharp

Dull

Elapse Time in Hours

Optimum Cutting Quality

Usable Cutting Quality

Backlapping Retains Optimum Cutting QualityBacklapping Retains Optimum Cutting Quality

Sharp

Dull

Elapse Time in Hours

Optimum Cutting Quality

Usable Cutting Quality

Height of Cut (HOC)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 SettingBench Setting

Distance Between Top of Bedknife and Bottom of Rollers

Effective Height of CutEffective 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)Frequency Of Cut (FOC)

Direction of Travel

Distance Traveled Between Consecutive Cuts

FOC FactorsFOC Factors

Number of Blades on Reel Reel Speed (RPM) Travel Speed

FOC Negative EffectsFOC 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

ObjectionableCut Quality

FOC “Guideline”FOC “Guideline”

The Lower the Height of Cut (HOC)The More Blades That Are Required

The Higher the HOCThe Less Blades That Are Required

Bedknife AttitudeBedknife Attitude

Down

Level Better Cut Quality Better Stripe Reduces Scuffing Accurate Height

of Cut Adjustment

Reel / Bedknife RelationshipReel / Bedknife Relationship

48

ESP Cutting Unit(Parallel Bedknife)

11.76 MM

.78 MM

Reel / Bedknife RelationshipReel / Bedknife Relationship

51

ESP Cutting Unit(Bedknife Angled Down 6MM)

13.43 MM

1.02 MM

All Greases Are NOT All Greases Are NOT Created EqualCreated Equal

All Greases Are NOT All Greases Are NOT Created EqualCreated Equal

Different Applications Require Greases with Characteristics that Meet Their Requirements

Bushing and Shaft