Richard Tremain is the product manager of flat saws for Husqvarna Construction Products. For over 19 years, he has focused on the development and refinement of flat saws, Soff-Cut saws and core drills. Tremain works in the field helping operators get the most of out their saws and striving to develop the latest generation of machine to increase production while keeping the operator less fatigued. Visit husqvarna.com.
Many factors of the jobsite are uncontrollable. However, two items that you can control are the equipment and diamond tooling selected for the job.
Most blade problems that arise in the field result from using the wrong blade for the job, using the blade improperly or equipment problems. For the purpose of this article, assume the equipment and diamond tooling are used on a walk-behind saw.
Walk-behind saws work in harsh environments. If they are not properly maintained, they will not be as efficient or productive. When a diamond blade won't cut properly, wears out too quickly or loses tensioning, it means the wrong blade was selected or there is an issue with the saw. An improperly maintained saw can cause all kinds of problems to the blade and cutting process. This is why it is important to inspect the saw prior to operation.
A visual inspection will help prevent issues while cutting. Check all the belts and blade collars. It is also a good idea to read through the operator's manual. Check that the blade is properly mounted, and that the operator is using the right RPMs for the blade. Checking equipment prior to operation is a good habit to form and could save time and energy, and improve your bottom line. The following are some of the most common diamond blade and equipment issues that occur in the field, and potential solutions to each issue.
1. Loss of tension
Blade will not stay straight while running
Cause: Blade was misaligned.
Solution: Check for proper saw alignment.
Cause: Blade is excessively hard for the material being cut, creating stress on steel center.
Solution: Double check that the blade was made to cut the material. If not, select a new blade.
Cause: Blade flanges are not the same size in diameter, creating uneven pressure on the center.
Solution: Confirm the correct blade collar diameter. It should be a minimum of 1/6 inch of the maximum diameter of the blade being used.
Cause: Wrong RPMs
Solution: Use the tachometer to ensure the blade shaft is turning at the proper RPMs for the blade.
2. Segment loss
One or more segments fall off the blade core
Cause: Blade is too hard for the material it is cutting, which creates excessive dullness, making the segments pound off or fatigue.
Solution: Switch to a softer bond.
Cause: Worn blade flanges fail to provide proper support and cause the blade to deflect.
Solution: Replace both blade flanges.
Cause: Out-of-round blade rotation results in pounding, caused by worn arbor or bad shaft bearings.
Solution: Replace worn arbor and/or bearings.
3. Overheated blade
Blade becomes too hot
Cause: Adequate coolant was not provided to the diamond blade.
Solution: Check water supply for adequate volume and for obstructions in the water system. Use dry blades only for shallow cutting (1 to 2 inches deep) or step cutting.
4. Arbor hole out-of-round
Arbor hole stretches so that it isn't a round circle
Cause: The saw arbor badly is worn due to improperly seated blades.
Solution: Before tightening the flange, make sure the blade is seated correctly on arbor shoulder.
Cause: Blade flange is not properly tightened permitting blade to rotate on the shaft.
Solution: Always wrench tighten the arbor nut. Never hand tighten the nut.
Cause: Blade flanges or arbor shaft are worn and not providing proper blade support.
Solution: Check blade flanges or arbor shaft for damage or excessive wear. Both flanges should be no less than that recommended by the manufacturer. Replace worn parts.
5. Blade won't cut
Blade spins in the cut without cutting the material
Cause: Blade is too hard for materials being cut.
Solution: Consult dealer or manufacturer for proper blade to cut the materials.
Cause: Insufficient power to permit blade to cut properly.
Solution: Make sure belts are not loose, saw is producing enough horsepower and it is running at the correct RPMs.
Cause: Blade has become dull because of continuous use on hard or vitrified material.
Solution: Consult the diamond tool supplier or the manufacturer.
6. Excessive wear
Segments are worn too quickly
Cause: If diamonds are highly exposed, you could be using the wrong blade on abrasive material.
Solution: Consult a dealer or manufacturer for the proper blade specification for abrasive material.
Cause: If the diamonds are highly exposed, there could be a lack of sufficient coolant to the blade.
Solution: If the saw is equipped with a water pump, make sure it is functioning properly. Check water supply at the blade.
Cause: Wearing the blade out-of-round accelerates overall wear. Usually, this can be caused by bad bearings, worn shaft or using a blade too hard for the materials that need to be cut.
Solution: Check bearings and arbor. If worn, replace with new parts before installing another blade.
Cause: Insufficient power caused by loose V-belts or improper RPMs.
Solution: Tighten belts taut or replace any worn belts.
7. Cracked core
Small, sometimes hairline, cracks form on the core
Cause: Blade is too hard for material being cut.
Solution: Use correct blade with softer bond.
Cause: Excessive cutting pressure, jamming or twisting the blade in the cut can cause the blade core to bend or flex. When subjected to extreme stress and metal fatigue, the blade's steel core will eventually crack.
Solutiion: The saw operator should use steady, even feed pressure, and be careful not to twist or jam the blade in the cut.
Cause: Overheating through inadequate water supply or improper use of dry cutting blades.
Solution: Use adequate water to cool wet-cutting diamond blades. Allow adequate airflow around dry-cutting diamond blades to prevent overheating. Never use a blade with a cracked core.
8. Uneven segment wear
Segments worn on one side, reducing side clearance
Cause: It is usually caused by misalignment of the saw or a lack of sufficient water on both sides of the blade.
Solution: Check saw alignment. Clean water system, and make certain that water is properly applied to the leading edge of the blade flanges. If machine is equipped with a water pump, check to see if it is supplying enough water.
Cause: Blade is worn out-of-round due to bad bearings, worn arbor or excessive dulling condition.
Solution: Replace bearings or worn arbor as required.
A lot of complications can occur in the field. Routine, proper maintenance on your saws and inspection prior to cutting are the keys to reducing the chance of any of these problems. To learn more about preventing blade issues in the field, read 5 Tips for Selecting the Right Diamond Blade.