How to Adjust a Bandsaw After Changing the Blade
Have you just fitted a new blade to your bandsaw? Before you start cutting, several adjustments need to be checked.
Simply installing and tensioning the blade is not enough. Its tracking on the wheels, tension, upper and lower blade guides, rear thrust bearing and guide height must all be checked in a logical order.
An incorrectly adjusted bandsaw can cause blade drift, vibration, blade overheating or premature wear of various components.
Conversely, spending a few minutes adjusting the machine after each blade change can help you make much better use of your bandsaw's capabilities.
In this guide, Probois Machinoutils explains step by step how to adjust a bandsaw after replacing the blade and, above all, the correct order in which the different checks should be carried out.
Key point: do not start by adjusting the bearings or blade guides. The blade must first be correctly installed, tensioned and positioned on the wheels. The guides are adjusted afterwards.
Why Should the Adjustments Be Checked After Every Blade Change?
Two blades designed for the same bandsaw do not necessarily behave in exactly the same way.
A difference in width, thickness or simply manufacturing characteristics can slightly change the way the blade runs on the wheels.
Whenever you replace a blade, it is therefore advisable to check:
- its installation direction;
- its tension;
- its tracking on the wheels;
- the upper blade guides;
- the lower blade guides;
- the rear thrust bearing or support;
- the height of the upper guide;
- and, if necessary, the squareness of the table and the rip fence.
The essential point is to follow the correct adjustment sequence. If you carefully adjust the guides and then make a significant change to the blade tension or tracking, the guides may need to be adjusted again.
Before You Start: Always Unplug the Bandsaw
Most of the operations described in this guide require working very close to the blade and wheels.
The machine must therefore be switched off and unplugged from the electrical supply before any manual adjustment or handling.
Do not simply rely on switching the machine off at its power switch.
Then open the upper and lower wheel covers according to the instructions in your machine's manual to gain access to the wheels and blade path.
Safety: the information in this guide is general. Bandsaw designs and adjustment systems vary between machines. The instructions provided by your machine's manufacturer must always take priority.
Step 1: Check That the New Blade Is Compatible With the Bandsaw
Before making any adjustments, make sure that the new blade matches the specifications of your machine.
In particular, check:
- the blade length;
- the blade width;
- the blade thickness;
- and the minimum and maximum dimensions permitted by the manufacturer.
A blade of the correct length is not automatically compatible with a particular machine.
A blade that is too wide or too thick for the machine's specifications may, for example, be subjected to abnormal stresses as it passes around the wheels.
Step 2: Check the Blade Installation Direction
It may seem obvious, but this is a mistake that can occur when changing a blade.
On a conventional woodworking bandsaw, the teeth must face in the cutting direction intended by the machine. On the descending section of the blade passing through the table, the teeth generally point downwards towards the table.
If the teeth are facing the wrong way, the blade will not cut normally.
Before continuing:
- visually check the teeth;
- check that the blade passes correctly through the different guide components;
- make sure that it is correctly seated on both wheels.
Never attempt to turn over or handle a blade while the machine is connected to the electrical supply.
Step 3: Temporarily Back Off the Blade Guides
Before accurately adjusting the tracking and tension, the guides should not artificially force the blade into a particular position.
Depending on the design of the machine, slightly back off:
- the upper side guides;
- the upper rear thrust bearing or support;
- the lower side guides;
- the lower rear thrust bearing or support.
The aim is to allow the blade to find its natural running position on the wheels during adjustment.
The guides will be adjusted accurately once the tracking and tension have been established.
Common mistake: immediately adjusting the bearings against a blade that is not yet correctly positioned on the wheels. This can result in using the guides to force the blade into position rather than actually guiding it.
Step 4: Apply Initial Blade Tension
The blade must now be given enough tension to remain correctly positioned on the wheels.
Use the tensioning system provided on your machine.
Many bandsaws have a scale that approximately corresponds to different blade widths. This indicator provides a starting point, but it should not necessarily be regarded as a precision measuring instrument.
The correct tension depends on the blade and the design of the machine.
A blade with insufficient tension may lack stability during cutting. Excessive tension unnecessarily stresses both the blade and the bandsaw components.
You should therefore not simply tension the blade as much as possible.
Step 5: Adjust the Blade Tracking on the Wheels
Blade tracking refers to the position maintained by the blade as it runs around the bandsaw wheels.
On many bandsaws, the angle of the upper wheel can be adjusted slightly using a knob located at the rear of the machine.
This adjustment changes the path of the blade across the wheel.
With the machine still unplugged, slowly rotate the upper wheel by hand in the normal direction of operation, where the procedure specified for your machine allows this.
Turn the wheel through several revolutions and observe the behaviour of the blade.
What matters is not only its position at a particular moment: the blade must maintain a stable path.
Does the Blade Always Have to Be Perfectly Centred on the Wheel?
It is often said that a bandsaw blade must always run perfectly centred on the wheel tyre. This rule is too general.
The correct position depends in particular on:
- the profile of the wheel tyre;
- the shape of the wheel;
- the width of the blade;
- and the design of the bandsaw.
On some machines fitted with crowned wheel tyres, the required adjustment may differ from that of a machine with a different wheel or tyre profile.
Always follow the instructions provided by the manufacturer of your bandsaw as a priority.
The essential point is that the blade remains stable on the wheels and does not continually try to move forwards or backwards as the wheels rotate.
Good practice: make tracking corrections gradually. After each small adjustment, rotate the wheel by hand several times and observe the new position of the blade.
Step 6: Finalise the Blade Tension
Once the blade is tracking correctly, check its tension again.
This step is important because tension and tracking can interact. A significant change in blade tension may slightly alter the blade's position on the wheels.
If you adjust the tension, check the tracking again afterwards.
Follow the tensioning procedure specified in your machine's manual. Some bandsaws have a tension indicator, while others use different systems.
Rule-of-thumb methods frequently found online should not replace the manufacturer's recommendations.
Step 7: Adjust the Upper Side Blade Guides
Once the blade is correctly positioned and tensioned, you can adjust the guides.
The side guides are designed to limit sideways movement of the blade when it is subjected to cutting forces.
Depending on the machine, they may consist of bearings, guide blocks or other systems.
Their exact position should be adjusted according to the manufacturer's instructions.
As a general principle, they should support the body of the blade without interfering with the teeth.
The guides should not be used to permanently straighten a blade that is incorrectly positioned.
If the blade moves sideways while running freely, first investigate a possible tracking, tension or blade problem.
Step 8: Adjust the Rear Thrust Bearing or Support
Behind the blade there is generally a rear thrust bearing or support.
Its function is different from that of the side guides.
When you push a piece of wood into the blade, the cutting force tends to push the blade backwards. The rear support limits this movement.
When the blade is not cutting, the correct adjustment depends on the guide system used on the machine. On many models, the rear bearing is positioned very close to the back of the blade without constantly applying significant pressure to it.
As the cutting force increases, the back of the blade can then engage the thrust bearing or support.
If the rear bearing is adjusted too far back, the blade can move backwards excessively. Conversely, an incorrect adjustment that causes significant continuous friction may result in heat and wear.
Follow the clearance or adjustment method specified by the manufacturer.
Step 9: Do Not Forget the Lower Blade Guides
This is probably one of the most frequently overlooked checks when adjusting a bandsaw.
The blade is not guided only above the table.
Most machines also have a guide assembly located below the table.
Depending on the machine, this may include:
- two side guides;
- a rear thrust bearing or support;
- a system for adjusting their position.
These components should also be checked after changing the blade.
A machine with perfectly adjusted upper guides but excessive play or incorrect positioning in the lower guides may still behave unstably during cutting.
Probois tip: when investigating the cause of an irregular cut, never check only the visible bearings above the table. Always inspect the lower blade guide assembly as well.
Step 10: Adjust the Height of the Upper Blade Guide
The upper guide assembly can generally be raised and lowered to suit the thickness of the workpiece.
During operation, it should be positioned as close as practical to the workpiece while maintaining the necessary clearance, in accordance with the machine's instructions.
Leaving the guide unnecessarily fully raised has two disadvantages:
- a greater length of blade remains unsupported between the guide and the workpiece;
- a larger section of the blade remains exposed.
Adjust its height whenever there is a significant change in workpiece thickness.
Step 11: Check That the Blade Is Square to the Table
If you want to obtain a 90° cut, you should also check the position of the table in relation to the blade.
With the machine unplugged, place an accurate square on the table and check the angle against the body of the blade.
Avoid positioning the square against the teeth, as the tooth set causes them to project alternately on either side of the blade body.
If necessary, adjust the table angle according to the manufacturer's procedure and then check the angle indicator.
A bandsaw can have a perfectly adjusted blade and still produce a cut that is not at 90° simply because the table is slightly tilted.
Step 12: Check the Rip Fence
If you use the rip fence for ripping or resawing timber, also check its adjustment.
It must lock securely and should not move under cutting pressure.
Depending on the machine, the blade being used and the type of work, blade drift may also need to be taken into account.
However, the rip fence should never be used to force a blade to follow a path that it does not naturally take.
If you have to apply strong sideways pressure to the workpiece to keep it against the fence, stop the cut and investigate the cause.
In What Order Should You Adjust a Bandsaw? Summary
| Order | Adjustment | Why? |
|---|---|---|
| 1 | Blade compatibility and installation | Start with a suitable, correctly installed blade |
| 2 | Temporarily back off the guides | Avoid forcing the blade path |
| 3 | Initial blade tension | Keep the blade correctly positioned on the wheels |
| 4 | Blade tracking on the wheels | Obtain a stable blade path |
| 5 | Final tension and tracking recheck | Stabilise blade operation |
| 6 | Upper side guides and rear thrust bearing | Support the blade during cutting |
| 7 | Lower blade guides | Guide the blade below the table |
| 8 | Table and rip fence | Check the cutting geometry |
| 9 | Running and cutting test | Confirm the adjustments |
Before Switching the Bandsaw Back On
Once all the adjustments have been completed, carry out one final visual inspection.
Make sure in particular that:
- all tools used for adjustment have been removed;
- all screws and locking systems are correctly tightened;
- the blade runs freely when the wheels are rotated manually according to the procedure specified for the machine;
- all guards have been refitted;
- the wheel covers are closed and secured;
- no parts or objects remain inside the machine.
Only after these checks have been completed should the machine be reconnected to the electrical supply.
Make a First Test Cut
For the first cut, use a stable piece of scrap wood that is suitable for the capacity of your bandsaw.
Start with a moderate feed rate and observe how the machine behaves.
The blade should cut smoothly without unusual vibration or abnormal noise.
If the blade drifts significantly, the machine vibrates or an unusual noise occurs, stop the machine and investigate the cause before continuing.
Do not attempt to compensate for incorrect adjustment by pushing the workpiece harder against the blade.
Why Can a New Bandsaw Blade Still Cut Crooked?
The fact that a blade is new does not, by itself, guarantee a perfectly straight cut.
If your bandsaw cuts crooked after changing the blade, several factors may be responsible:
- incorrect blade tension;
- incorrect tracking on the wheels;
- incorrectly adjusted blade guides;
- incorrectly positioned rear thrust bearing;
- lower blade guides not checked;
- incorrectly adjusted table or rip fence;
- a blade unsuitable for the work being carried out;
- or an issue with the blade itself.
It is therefore better to check the machine methodically rather than immediately concluding that the new blade is defective.
Frequently Asked Questions About Bandsaw Blade Adjustment
Should the guides be adjusted before or after tensioning the blade?
The guides should be finally adjusted after the blade tension and tracking have been established. They should not be used to artificially force the blade into position.
Should the blade touch the side guide bearings?
The correct adjustment depends on the guide system used. Depending on the machine, bearings or guide blocks may be positioned very close to the blade or may operate with light contact under certain conditions. Follow the instructions in the machine manual and, above all, avoid any adjustment that forces the blade sideways.
Should the rear thrust bearing rotate continuously?
This also depends on the design of the guide system. On many machines, the rear thrust bearing is positioned very close to the back of the blade and mainly comes into action when cutting pressure pushes the blade backwards. The exact adjustment should follow the manufacturer's recommendations.
Why does the blade move across the wheel when I turn it by hand?
If the blade continually moves forwards or backwards, the tracking should be checked. Also inspect the blade tension, the condition of the wheel tyres and the blade itself. An unstable blade path should not be compensated for by the guides.
Should the lower guides be adjusted every time the blade is changed?
Yes, their position should at least be checked. A blade with a different width or thickness may require the lower guide system to be readjusted.
Can the machine's blade tension indicator be used as an exact value?
On many machines, it should primarily be regarded as a useful reference. Its accuracy and operation depend on the model. Use it in accordance with the manufacturer's instructions and the blade installed.
Conclusion: Correct Bandsaw Adjustment Starts With the Right Sequence
After replacing a blade, cutting quality depends as much on the blade itself as on the adjustment of the bandsaw.
Above all, remember the following sequence:
BLADE → TENSION → TRACKING ON THE WHEELS → UPPER GUIDES → LOWER GUIDES → TABLE → TEST CUT
This method helps prevent you from adjusting the guides around a blade that has not yet found its correct running position.
A methodical adjustment helps provide a more stable blade, a more consistent cut and avoids placing unnecessary stress on the machine's components.
Finally, if despite these checks your bandsaw still does not cut straight, do not automatically replace the blade again: also check the condition of the guides, bearings, wheel tyres and the other mechanical components of the machine.
At Probois Machinoutils, you will find bandsaw blades as well as a wide range of spare parts for the maintenance and repair of woodworking bandsaws.