A bandsaw blade may come off the wheels at an inconvenient moment. For instance, when a person is feeding a cherry board into a curve in the workpiece, the bandsaw blade may start to slap against the bandsaw tire. The bandsaw will stop, a person’s heart will race, and the person will spend twenty minutes attempting to determine the cause of the bandsaw problem.
This situation is frustrating, wastes lumber, and is dangerous should a person not pay attention to the bandsaw. Many woodworkers will encounter this problem at some point in time. However, if a person understands what is happening and why the bandsaw blade came off of the wheels, that person will be able to fix it and avoid having this happen again.
Most of the time, a person will find that poor tension of the bandsaw blade caused the bandsaw blade problem. In almost every case, the bandsaw saw is providing information to the woodworker about the tension, alignment, or technique used when operating the bandsaw. With these insights from the bandsaw, a person can fix the problem and keep the bandsaw blade on its proper position.
Although the fixes for a bandsaw blade jumping off of the wheels may seem mysterious at first, there are steps that a woodworker can follow to fix the problem. The following instructions will provide information to a person about what works for those who encounter the problem where the bandsaw blade refuses to remain in its proper position. The first thing that a person should examine on a bandsaw blade that jumps off of the wheels is the tension of the bandsaw blade.
Steps to Fix a Jumping Bandsaw Blade
1. Check the Tension of the Bandsaw Blade
If a bandsaw blade is too loose, it will jump off of the wheels. The tension screw on a bandsaw blade comes with a tension scale to assist the woodworker in finding the proper tension. However, the scale is only a rough guide to the proper tension.
To find the proper tension for the bandsaw blade, gently pluck the bandsaw blade as if tuning a bass string. If a bandsaw blade creates a clear musical note, then the tension is set correctly. If the bandsaw blade makes a dull thud when plucked, then the tension is too low.
Experienced bandsaw users may choose to turn the tension screw a quarter turn past the mark on the bandsaw tension scale when using blades that are three quarters of an inch in width or more. This setting for the tension will allow the bandsaw blade to track straight through thick pieces of lumber. However, leaving the bandsaw in this setting for many days will eventually lead to a stretched bandsaw blade and fatigued saw wheels.
To avoid this issue, woodworkers should release the tension on the bandsaw blade when they are finished using the bandsaw for the day. Establishing this habit will prevent tracking problems. The second thing that a person should examine on a bandsaw that has a bandsaw blade that jumps off of the wheels is the tracking of the saw’s wheels.
2. Verify the Tracking of the Saw Wheels
The wheels need to track in the same plane. If a person closes the covers of the bandsaw and shines a light behind the blade, the shadow of the bandsaw blade on the upper wheel should be even on both sides of the blade. If one side of the shadow is thicker than the other, the upper wheel is not tracking in the same plane as the lower wheel.
To fix the problem, the person should adjust the tracking knob in very small increments. A person should not adjust the tracking knob more than an eighth of a turn. After each adjustment, the bandsaw should be started to see the effect of the adjustment.
The goal is for the bandsaw blade to be in the dead center of the crown of each wheel. Once this setting is found, any change in the tension setting or blade width will require only a very slight adjustment to the bandsaw blade to get it to track properly. Many people make the problem worse instead of better by making large adjustments to the tracking with every change of bandsaw blade.
The third thing that a person should check on a bandsaw whose bandsaw blade jumps off of the wheels is the amount of dust and debris that has accumulated on the wheels. A person can easily see the debris on the bandsaw blades by turning the saw on and looking into the blades. However, the debris may not be easily seen on the tires of the bandsaw.
3. Clean Accumulated Dust and Debris
Using a soft brass brush or even an old toothbrush, a person should scrub the bandsaw tires while the bandsaw is turned off. Once the tires have been scrubbed, a rag dampened with a little denatured alcohol can be used to scrub the tires again. This process will remove alot of the gray crud that may have accumulated on the tires.
Once a person has cleaned the bandsaw tires, the person should spin the wheels by hand while observing the movement of the bandsaw blade. If the bandsaw blade develops a wobble only after turning the wheels a few revolutions, this indicates that there was a flat spot or another buildup of sawdust on the tires that was not visible to the individual. Sawdust on the tires creates high spots that push the bandsaw blade sideways and off of its track.
Cleaning the tires will fix this problem. The final thing that a person should check on their bandsaw if their bandsaw blade jumps off of the wheels is the position and angle of the bandsaw blade’s guides. There are three blade guides on a bandsaw table, the upper blade guide and the two side blade guides.
4. Adjust the Position and Angle of Blade Guides
The upper blade guide’s thrust bearing should be positioned about one sixteenth of an inch behind the bandsaw blade when the bandsaw is not running. The side blade guides should be positioned so that they almost touch the bandsaw blade, but they should not quite make contact with the bandsaw blade when the bandsaw is not cutting. The side guides will make contact with the bandsaw blade when a person begins to cut the wood piece on the bandsaw.
If the bandsaw blade’s guides are touching the bandsaw blade while the bandsaw is idling, the person will hear a faint singing sound emanating from the bandsaw, and the bandsaw blade will quickly heat up. This heat will soften the bandsaw blade’s steel, which can make the bandsaw blade more likely to slip off of the bandsaw’s wheel. Proper guide adjustment should be quiet, but this adjustment will help to prevent any troubles from arising with the bandsaw.
Not every bandsaw blade is appropriate for every job. For example, a narrow three eighths inch bandsaw blade with fine teeth is appropriate for cutting tight curves, but that same narrow bandsaw blade can flex easily when cutting thick hardwoods, which can lead to those teeth of the bandsaw blade leaving the bandsaw’s wheel. A wider bandsaw blade with fewer teeth per inch will solve this problem.
5. Select the Correct Blade Width
A wider bandsaw blade has more beam strength, and more beam strength allows it to better resist the twisting forces that would cause a narrower bandsaw blade to leave the bandsaw’s wheel. The catch to this solution is that bandsaw blades cannot be forced to cut around a turn that is too small for that blade’s teeth without risking the teeth of the bandsaw blade breaking or the bandsaw blade overheating from the effort of forcing it around the turn. Therefore, the person should select the bandsaw blade of the required width for the job to eliminate derailments of the bandsaw blade.
The alignment of the bandsaw’s wheels themselves is another factor that can impact the bandsaw blade. If the upper wheel is forward or backwards of the position of the lower wheel, the bandsaw blade will tend to corkscrew itself off the bandsaw’s wheels. A bandsaw allows the person to shift the upper wheel forward or backwards relative to the saw’s body using a setscrew or tilt adjustment.
6. Align the Bandsaw Wheels
A person can mark a spot on the bandsaw blade with chalk, and then mark a spot on the bandsaw’s body that aligns with that spot when the blade is running in the bandsaw’s wheel. Then, when the bandsaw is running, the person can observe the chalk spot on the bandsaw blade to see if it consistently lines up with the mark on the saw body. If the chalk spot consistently lines up to one side of the mark on the saw body, the saw blades wheels are out of alignment with each other in the plane of the saw.
The wheel alignment can be quickly adjusted so that the bandsaw feels as if the bandsaw was rebuilt. The way that the bandsaw blade is fed into the bandsaw also has an impact on the bandsaw blade’s tendency to leave the bandsaw’s wheels. If a person pushes too hard on the bandsaw or twists the wood board that is being cut with the bandsaw blade, the blade will lean against the bandsaw’s wheels.
Eventually, because the blade is being forced to lean, the bandsaw blade will hop the bandsaw wheel. Therefore, a person should keep their hands light on the bandsaw, and allow the bandsaw blade to do the work. Using the bandsaw fence or a pivot block will allow the person to change the direction of the bandsaw without forcing the bandsaw blade to hop the wheel.
It helps for a person to stand slightly to the side of the cut with the bandsaw such that a person can see both the front and back of the bandsaw blade. Being able to view the bandsaw blade this way will allow a person to notice when the bandsaw blade begins to drift from the center of the wheel, and to correct that drift prior to the bandsaw blade leaving the bandsaw tire. While it may not seem like it, using the proper saw technique is a free and effective way to improve the performance of the bandsaw.
If a bandsaw blade is dull, the bandsaw blade will require more pressure from the person to push the bandsaw blade forward through the wood. This extra pressure on the bandsaw blade will cause that bandsaw blade to twist within the bandsaw’s guides. This twisting can lead to the bandsaw blade leaving the bandsaw’s wheels.
If a person finds a bandsaw blade to be particularly dull, or if the bandsaw blade sounds as if it is struggling to make the cut, a person should change a bandsaw blade. A fresh bandsaw blade will cut through the wood more easily, and will create less heat within the bandsaw saw. Many woodworkers will have two or three bandsaw blades that they rotate between each other.
8. Replace Dull Blades
Instead of fighting with a dull blade for another hour, woodworkers can simply change the bandsaw blade. The improvement in performance when using a fresh bandsaw blade will be dramatic. Every bandsaw blade has limits.
For instance, a ten inch bandsaw blade will flex if attempting to cut an eight inch thick slab of maple wood. No matter the tension, tracking, or placement of the bandsaw blade’s guides, the blade will flex against the wood. A person should recognize these limits of the bandsaw, and either resaw the wood into thinner boards, or take the work to another saw that is built to handle such thick wood.
Pushing a bandsaw beyond its limits will quickly destroy blades and frustrate the woodworker. Respecting the limits of the bandsaw blade will ensure that the bandsaw blade remains on the bandsaw’s wheels. Once a person has learned these tips and strategies, a person will find that their bandsaw blade remains on the bandsaw’s wheels throughout the morning’s use.
The blade will be quieter, the cuts will be straighter, and a person will no longer waste time struggling with bandsaw blade issues that may occur every few hours. The next time that a bandsaw blade jumps off the wheel, a person should not jump to fixing the random knobs on the bandsaw. Instead, a person should follow a list of steps to diagnose and fix the problem.
First, a person should check the tension of the bandsaw blade. Next, a person can check the tracking of the bandsaw blade. Following that, a person can clean the tires of the bandsaw.
Then a person can check the placement of the bandsaw blade’s guides. After that, a person can check the choice of bandsaw blade. Next, the person can check the alignment of the bandsaw’s wheels.
Finally, a person can inspect the pressure with which the bandsaw blade is being fed into the wood. One of these factors is responsible for the bandsaw blade jumping off of the bandsaw wheel. Fixing that one factor will allow the saw to run smoothly into the next board.
