GENERAL TROUBLESHOOTING
Locate your problem below and follow across the row to locate the possible causes, marked with an ‘X’. Follow the column to the top to determine the possible cause. Click on the cause for more information. | POSSIBLE CAUSES | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| BAND TRACKING | ||||||||||
| CHIP BRUSH | ||||||||||
| CUTTING FLUID | ||||||||||
| TOOTH PITCH | ||||||||||
| FEED RATE | ||||||||||
| BREAK-IN PROCEDURE | ||||||||||
| BAND TENSION | ||||||||||
| BAND SPEED | ||||||||||
| GUIDE | ||||||||||
PROBLEMS | Heavy wear on tips & corners of teeth | x | x | x | x | |||||
| Tooth strippage | x | x | x | x | x | x | ||||
| Butt weld breakage | x | x | x | x | ||||||
| Body breakage or cracks from gullets | x | x | ||||||||
| Body breakage or cracks from back edge | x | x | x | x | ||||||
| Heavy wear and swagging of back edge | x | x | x | |||||||
| Broken band shows a twist in band length | x | x | x | x | ||||||
| Chips welded to tooth tips | x | x | x | x | ||||||
| Heavy wear on both sides of band | x | x | ||||||||
| Gullets loading up with material | x | x | x | x | ||||||
| Fractured tooth tips | x | x | x | x | x | |||||
| Rough cut | x | x | x | x | x | |||||
| Inaccurate cut | x | x | x | x | x | x | ||||
As with any manufacturer, saw blade companies maintain strict production quality control standards in order to provide the best possible product to their customers. Except for weld breaks, most saw cutting problems are caused by a combination of incorrect speeds and feeds, operational procedures or an improperly maintained saw.
BREAK-IN PROCEDURE
Break-in a new band according to manufacturer’s instructions, using the same material as will be cut. Minimum break-in procedure would be to set band speed according to the correct speed chart. Reduce feed pressure 1/2 or 1/3 of the recommended rate. Cut square inches recommended by the manufacturer of the blade. After break-in, gradually increase feed pressure until ideal chip curl is reached.
BAND TENSION
| BLADE TYPE | RECOMMENDED TENSION (PER SQUARE INCH) |
|---|---|
| FLEX BACK CARBON BANDSAW BLADES | 15,000-20,000 PSI |
| HARD BACK CARBON BANDSAW BLADES | 20,000-25,000 PSI |
| BI-METAL BANDSAW BLADES | 25,000-35,000 PSI |
BAND SPEED (SFPM)
A correct band speed achieves a correct shear angle producing an ideal chip and more efficient cutting
If the band speed is too high, the shear angle will also be too high, allowing the band to ride through the material producing thin chips and wearing the edges of the teeth.
If the band speed is lower than recommended, the tooth tries to take chunks of material, causing stress on the tooth, possible breakage or stalling in the workpiece.
Identify the material you are cutting, locate it or a material close to the same characteristics on our band speed chart and adjust speed accordingly – use the high side of the range with a new band, reduce to the low side as the band wears.
FEED RATE
| MACHINABLITY RATING OF METAL BEING CUT | BLADE SPEEDS | RECOMMENDED FEED PRESSURES | |
|---|---|---|---|
| MACHINES WITH SET SPEEDS | MACHINES WITH VARIABLE SPEEDS- FPM | ||
| GROUP 1 – EASILY MACHINED | FAST | 110-350 | MEDIUM LIGHT |
| GROUP 2 – MODERATELY DIFFICULT TO MACHINE | MEDIUM | 80-150 | MEDIUM |
| GROUP 3 – DIFFICULT TO MACHINE | SLOW | 50-110 | MEDIUM HEAVY |
| GROUP 4 – EASILY MACHINED – NONFERROUS | FAST | 110-300 | MEDIUM LIGHT |
TOOTH PITCH
A tooth pitch that is too fine for a particular cross section will result in gullet loading, slower cutting rates and greatly reduced band life.
A tooth pitch that is too coarse for a particular application can result in band breakage, stalling in the work piece or tooth damage.
In general, a tooth pitch slightly too coarse for a particular cross section is preferable to a pitch that is too fine, if adjustments to cutting parameters and approach to the work piece are made.
CUTTING FLUID
Always measure and mix coolant according to the instructions provided by the manufacturer. Degraded or poorly mixed coolant can be totally ineffective.
Prepare the coolant mixture by slowly pouring the concentrate into the water while stirring the mixture vigorously. Mix coolant in a separate container and then pour it into the reservoir. Do not mix in the reservoir.
When adding make-up coolant to the reservoir, follow directions of the manufacturer. Mix in a separate container before pouring into the reservoir.
Adjust the coolant nozzle so that fluid completely covers both sides of the band on the side entering the work piece.
Use an adequate flow of coolant. Full flow is seldom too much coolant.
Fluid should be running before running the band. Let the saw run long enough to carry fluid into the work area before starting the cut.
Keep a properly mixed supply of replenishing fluid on hand, never add “water only” to the reservoir.
CHIP BRUSH
Check the condition and adjustment of the chip brush routinely. Work hardened chips, if carried into the kerf by band gullets, may cause damage to the band set, tooth stripping or a scoring effect on the cut surface.
The chip brush, to be effective, must be properly adjusted. The shaft should be parrallel with band travel. The brush should clean all chips from the tooth gullets without touching the bottom of the gullets.
GUIDES
Guide arms are adjustable in order to expose the saw band to as little upward stress as possible. Beam strength is dramatically increased when the distance of band flex is reduced to a minimum. Stress cracks in the band and probable eventual breakage can be caused by allowing the band to flex upward.
Always adjust guide arms as close to the work piece as possible without interfering with the cut.
BAND TRACKING
The term tracking refers to the act of positioning the blade on the bandsaw wheels so it is in proper relation to the table, work piece, backup bearings and saw guide inserts.
To position it properly, tilt the top wheel (the angle of the top wheel steers the blade in the direction of the tilt). Track the blade when it is under full tension. When a blade is properly tracked, it will run in a straight line.
