Flat Saw Training

Flat Saw Sizes

– Low Horsepower• Blade diameters range from 8” (200mm) to 18”

(450mm)• Power ranges from 4 to 25 horsepower

Flat Saw Sizes– High Horsepower

• Blade diameters range from 14” (355mm) to 60” (1524mm)

• Power ranges from 30 to 99 horsepower

FLAT SAW DEFINITION

• Rides on surface to be cut.

• Self Propelled

• Push

FRAME AND SUPPORT SYSTEM

– Blade Shaft Drive• Engine

– Gas– Diesel

• Motor– 60,50 cycle– High cycle– Hydraulic

FRAME AND SUPPORT SYSTEM

• Shaft and Bearing Assembly– Blade location.

• The blade location is maintained by the fit and finish of the blade shaft

– Blade clamping. • All power is transmitted to

the blade via the blade collars which are sometimes referred to as blade flanges

Wheel System

• Front Wheel System– Raises and lowers the saw

• Manual• Hydraulic• Electric

– Supports a portion of saw weight when blade is out of the cut

• Weight is removed when the blade is in the cut• Used to maneuver the saw on front pivot models.

Wheel System

• Rear Wheel System– Guides the saw in

the cut• Counters the lead

bias of the blade– Saw alignment is

adjustable

– Powers the saw forward

Cowling System

• Supports and houses• Operator controls• Fuel storage• Performance and

warning indicators

• Functions as a safety guard

Blade Guard System

• Front portion should be removable or pivot up.– Allows for cutting

up to a vertical surface

• Supplies coolant to the blade

Functions of a Flat Saw

• Locate the diamond blade

• Provide vibration free torque to the diamond blade

• Guide the diamond blade in the cut

• Supply water to the diamond blade

• Provide an interface between the Operator and the diamond blade

Blade Location

• Main function of the saw system

• Blade is held concentric to the shaft 0.000” to 0.004” for conventional shafts and 0.008” to 0.015” for “Quick disconnect” shafts

• Blade shaft assembly locates the diamond blade

Most Common Blade Shaft Problem

• A groove is formed where the blade contacts the shaft

• Caused by the blade spinning in relation to the shaft– Missing drive pin in blade collar– Improper tightening of blade collar bolt– Worn or dirty blade collars– Worn out bearings

Blade Shaft Components

Outer Collar

Fixed Collar

Drive Pin

Blade Contact Area

Husqvarna Blade Shaft

The Problem

• Groove occurs because the blade core metal is much harder than the blade shaft

• Groove allows the blade to mount off center of the blade shaft

The Problem

Groove

How Does This Happen?

• Sheared drive pin– Improper mounting– Blade collar bolt loose

• Missing drive pin– Non-attentive, or unaware operator– Non-attentive, or unaware mechanic

Pin Hole Clearance

Clearance

Drive Pin

The Blade Collar & Drive Pin

Torque TransferFaceDrive Pin

DRIVE PINS DO NOT SUPPLY TORQUE TO THE BLADE!

DRIVE PINS ARE INSURANCE AGAINST BLADE TO SHAFT ROTATION

Blade Collars

• Inner and outer collars must be the same diameter

• Blade collars are not depth stops

Blade Collars

THE RESULT

• Core cracked blades

• Out of round blades

• Blades pound

• Reduced cutting efficiency

• Increased cost

• Unsafe Condition

Torque to the Blade

• V belts and sheaves transmit torque from the power supply to the blade shaft

• The sides of the V belt transmits power via wedging action with the sheave

• Sheaves must have large enough diameter to keep V belt in contact with sheave walls

Minimum Sheave Diameter

Lift off

Concrete saws useCustom built sheaves.

Why? Because the sheave Diameter is too small forThe V belts

This is why a 85 HP saw Uses 8, 10,12,… V beltswhen you would normally Use 2 to 3 for this power Range.

V Belt / Sheaves

• V belts wear

• Sheaves wear– Sheaves should be replaced after 3 to no

more than 5 sets of belts have been used– All belts should be checked and re-

adjusted after the first 2 to 4 hours of use depending on horsepower and application.

V Belt Issues

• Can not keep a set of belts in service longer than a month

• No matter how tight the belts are they squeal

Simple Check

• If the area between grooves of a sheave has a sharp edge, replace

• If the bottom of the sheave groove shines, replace

Worn Sheaves

Saw Alignment

• Concrete saws are designed to veer off to the left when a blade is not in the cut

• Compensates for the pull of the blade being on the far right side

• Operators are not supposed to Fight the saw

Saw AlignmentLead off caused by the blade

Lead off of the saw, 6 to 10 inchesIn 10 ft

Alignment Adjustment

• Most competitor’s saws have an alignment bolt located at the bottom rear left hand corner of the saw frame

• Alignment bolt moves the left rear wheel forward or backward creating more or less lead off

• Set up is blade size and Operator specific

Saw AlignmentAlignment Bolt

Husqvarna Alignment (Tracking) System

• Electric tracking system known as “E” Track.

• Allows operators to make adjustments while sawing without taking eye off of pointer.

Rear Wheels

• Locates the saw in relation to the blade– When cutting the saw is supported on the 2

rear wheels and the blade

• Powers the saw through the cut

• The right wheel always wears quicker than the left

• NEVER REPLACE JUST ONE WHEEL

Rear Wheels

Blade Guards

• Blade guards are heavy

• Protects the operator and surrounding area from flying debris

• Supplies water to the blade– Water must be evenly distributed on both

sides of the blade

Blade Guards

• The front portion of the guard lifts up to allow cutting up to a vertical surface

• Blade guard hinges can not be made strong enough– Hinges are damaged by the way we transport

the saw to and from the job site– Front portions of guard is never to be in the

up position during transport

Blade Guards

Blade Guards

Water Tubes

Transmissions

• Most saws use hydrostatic transmissions

• Gear reductions of 40 to 1 or greater are used

• Final drive is usually via chain and sprocket

Transmissions

• Chain drives are NEVER to be lubricated– Lubrication will cause failure

• Chains are to be tight– No slack allowed in the chain– Loose chains cause poor cuts, increased

labor cost, and decreases blade life

Transmissions

Husqvarna Drive System

• No chains or sprockets.

• No surging or lagging.

• Consistent and predictable forward movement.

• No maintenance!