The integral part of woodworking and a must-have item in a woodshop is a bandsaw. But many people find it difficult to cut a straight line with it. And they wonder why their bandsaw not cutting straight. Some people fail to cut woods with a consistent thickness. No matter how thick is the material or what size the saw blade you are using, the saw blade wanders undoubtedly.
Maybe you have tried sawblades of different sizes, changed guide blocks, opted for alternative fences, or perhaps you have tried all these things. But still, the saw blade wanders and drifts from the bandsaw fence. Okay then, no need to go anywhere; this article is the answer to your question, “why does my bandsaw blade wander?” You will get the proper guideline too to troubleshoot the problem.
Main reasons behind wandering the bandsaw blade
1. If you use a high tension blade, your bandsaw can wander. Usually, bandsaws have any one of the two blade tensioning mechanisms, either pneumatic or screw over spring. The hydraulic tension mechanism is the same as the pneumatic mechanism but with higher pressure and more messy oil leakage.
For the screw over spring mechanism, our recommendation is to get a blade tension gauge to achieve correct blade tension. You have to use a pressure regulator valve for a pneumatic or hydraulic mechanism for proper blade tension.
Usually, manufacturers give a chart mentioning the pressure range to achieve the required tension for different sizes of blades. The range of air pressure is 10 to 120 psi. Set the saw with the correct pressure; the machine will do the rest.
2. Because of waste assortment, a fast feed rate can be the reason for wandering your saw blade.
3. Excess heat produces from the friction can be the reason for blade deflection.
4. Incorrect blade installation can cause bandsaw drift. Maximum bandsaw operators have the worst experience regarding the unsuccessful blade installation that wanders constantly. There are some specialty blades, like honeycomb-style blades; you should check these carefully before installation.
5. Next, you should be careful about the storage of the blade as a plain laid blade can get damaged and cause edge wandering. We recommend hanging the blade from the wall to prevent drifting.
6. If still the blade wanders, it indicates you may have a dull blade. You can test the sharpness by cutting scrap wood. If you need to apply excessive force to run the wood through the blade or you find wisps of smoke coming from the blade or the wood, that means it is dull. Extreme pressure on the blade results in twisting right or left.
Moreover, if the teeth are burnt or bent by hitting a nail, screw, or embedded rock in the wood, you need to change the blade. Follow the direction of the bandsaw manufacturer and replace the old one with a new one.
7. If the blade is sharp and tension is okay but still bandsaw blade drift, you should check how it tracks the wheels. In general, there is a crown on the blade support wheels in the high-speed machines. If the blade runs near or at the center of the crown and not that close to the front or back of the wheel edge, it is okay. However, if the blade is on the wheels barely, it is necessary to align the wheels correctly.
8. Improper alignment of guides can lead the blade track improperly on the wheels. So before adjusting the blade wheel, check the blade guide adjustment. Though it is a misconception that the guides hold the blade in place, the truth is they are for backup.
The crown of the wheel keeps the blade in the right place. The blade always tries to climb the top of the crown. When the wheels are worn out and do not have a clear top to the crown, the blade cannot find where to go and wanders around.
9. If the blade does not stay centered in the slot after adjusting the tracking properly, you may need to clean the wheel. Because the dirty wheel is another reason for band saw drift.
If sawdust creates buildup onto the wheel, the blade wanders back and forth inside the slot. In such a case, we advise turning off the saw, remove the blade, scrape off the sawdust with a putty knife, wipe off the blade, reinstall it, turn the saw on, and readjust the tracking.
10. Ensure that the blade is running in the right direction; otherwise, it is impossible to achieve the desired cut.
11. For all vertical blade band saws, the cutting point of the blade should go down to force the workpiece down into the table. Otherwise, the saw blade will try to lift the workpiece above from the table.
12. In almost all horizontal bandsaws cases, the blade’s cutting point runs towards the blade wheel connecting to the saw motor. If it does not happen so, it may be the cause of wandering.
We highly recommend calling an experienced electrician if the blade still runs in the wrong direction.
Bandsaw drift adjustment technique
1. Adjusting the tension
Fix the blade’s tension correctly, as it will come off the wheel if it is too loose or tight. For the tension adjustment, turn off the power of the bandsaw. Then take a flat stick and place its tip against the blade side, ¾ inch above the point from where the blade emerges from the slot on the table.
Now push the blade using moderate pressure with the stick. The blade is looser if you can move it over ¼ inch. On the other hand, if you cannot move the blade more than 1/8 inch, it indicates the blade is too tight. To tighten the blade, turn the large and knurled knob clockwise located on top of the bandsaw. To loosen the blade, turn the knob counterclockwise.
2. Using a fence
Each bandsaw deserves a fence as you can use a bandsaw more conveniently with it. A bandsaw can do more than cutting curves. If there is a good fence, you will be able to resaw woods into thinner pieces. You can also rip through rough warped lumber without being tensed about kickback and precisely cut half-lap joints, tenons, etc. Moreover, you will be able to prevent blade drift.
Commercially available fences are great to use and easy to install. However, you can make them by yourself too with remarkably less expense. You will need some basic tools, like bandsaw, square, hand plane, level, clamp, and materials, like plywood, wood, water-based polyurethane, vertical toggle clamp, and bolts to prepare it.
3. Adjusting the bandsaw
To adjust the bandsaw, you have to set up a few things. But the main problem is with the blade on the wheel that drifts off the line always.
• We recommend not to set the blade on the center of the wheel.
• Aim to keep the blade guides 1/16 inch from the blade.
• There is a pair of ball-bearing on the back of the blade. Make sure they do not touch each other. Otherwise, the blade will wander.
4. Using a vortex tube
We have already mentioned that overheating caused by friction is a reason for wandering your saw blade. Using a vortex tube can be a solution to this problem.
We can consider that you have got your answer to the question, “why does my bandsaw blade wander?”. By taking care of properly and using the correct equipment, you can solve the problem.
Sharpening the bandsaw regularly, centering the gullet in the proper place, using the moderate tension blade can cause the saw blade to wander less. If, after all these things still, your band saw not cutting straight, we recommend contacting a professional. Or you can purchase a new one.