A well-aligned miter saw is the simplest and most accurate tool in the shop for cross-cutting lumber. If your saw has been used on a job site, or if it’s been awhile since its last calibration, it’s probably at least a little out of alignment. Read on for the step-by-step tutorial to align your miter saw and get back to those precise cuts.
Make sure your saw is clean before you start so that no sawdust or wood chips affect the measurements. I recommend a vacuum. It’s quick and easy.
Also, just for the record, I did clean my saw before starting … but she’s been well-loved all her life and it shows …
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Tools & Supplies
- Miter Saw (I’m guessing you have one of those since you clicked on this post … )
- Framing Square
- Speed Square
- Combination Square
- Lumber for test cuts
Step 1. Blade
Check the blade for pitch build up, especially if you work with a lot of soft wood. If necessary, give the blade a quick clean with some laundry detergent and water. Head over to this video from Woodworker’s Journal if you want more info.
Step 2. Table and Fence Alignment
Most miter saws have a solid, flat cutting surface. However, it’s good practice to confirm your saw’s alignment before adjusting the rest of the saw. Place a level or straight-edge across the table and check for any gaps.
Next, place a level or straight-edge against the fence and check for gaps.
If there are no gaps, you’re good to go. If there are gaps, the fence can be adjusted by screws along the back of the saw. Adjust the table and fence as necessary.
Step 4. Miter Angle
Once you’ve confirmed proper table and fence alignment, it’s time to adjust for precise miter cuts.
Loosen the detent plate screws. You may have to move the arm of the saw in order to reach all the screws.
With the screws loosened, lock the saw into the 0° stop on the detent plate.
Align your square with the blade and fence and rotate the arm of the saw to find the true 90° angle.
Re-tighten the plate screws. Start with the outside screws and then rotate the saw arm to access the inside screws.
If your saw is at a true 90° and locked into the 0° stop on the detent plate but the miter indicator doesn’t read exactly 0, you may have to adjust the indicator. Simply loosen the screw that holds it in place, adjust it to the correct position, and retighten the screw.
Step 5. 90° Bevel Angle
Unlock the bevel adjustment. Align your square with the table and blade. Adjust the 90° bolt at the back of the saw until the blade is at true 90°.
If your saw is at a true 90° but the bevel indicator doesn’t read exactly 90°, you may have to adjust the indicator. Simply loosen the screw that holds it in place, adjust it to the correct position, and re-tighten the screw.
Step 6. 45° Bevel Angle
Remove the fence from one side of the saw and tilt the blade toward the 45° bevel position. Align your square with the table and blade.
Adjust the 45° bolt until the blade is at true 45°.
Repeat on other side if you have a dual bevel saw.
Step 7. Check Accuracy
Finally, make some test cuts in order to confirm that your saw is calibrated correctly. Repeat any alignments as necessary.
Once you’ve ensured all alignments are accurate, carry on with your projects!
I hope you find this tutorial straightforward and helpful. Please leave any questions and/or comments and I’ll get back to you as soon as possible.