My miter saw isn't cutting square anymore - help!

17 years ago

I am a very novice woodworker in the middle of a closet shelving project. Over the past day or so, my miter saw (a couple years old, lightly used) has started making unsquare cuts. I am using to cut straight down through wood on a 90 degree angle, no bevels or miters. The finished cut is a little bit off from 90 degrees. I haven't changed any of the settings.

I assume something has loosened up somewhere, but I'm not sure where to start. If I put a square between the fence and the blade, the blade is a tiny fraction off from square. I haven't adjusted anything so whatever it is came loose by itself. My instructions tell me I can adjust the blade parallel with the table or I can adjust the fence. Which one should I try, given that I haven't messed with either one yet. I tried unscrewing the fence a bit but the screws are very tight and won't budge, so I'm guessing the fence is tight and that maybe the blade is loose?

Any suggestions are welcome! I really want to finish this project but I can't if all my cuts are skewey! Help!

Sort by:Oldest

Comments (8)

User
17 years ago
The saw brand might shed some light on the problem.

First, check the fence/table for any chips that might have gotten stuck under the fence and keep the boards from touching the fence. Also make sure there is no play in the motor and arm and that the blade is mounted securely.

Double check the detent setting on 0, making sure there is no movement. Then check the blade for square to the fence----then rotate the blade 90 degrees and recheck for square---repeat for a total of three turns---that makes sure the blade is not warped. If it is still out, check the adjustment that allows for moving the blade.

If none of those are a problem, then you need to adjust either the fence or the arm. Pick whichever adjustment is easiest.
kudzu9
17 years ago
Any power saw can get out of square, and any decent saw will have bolts that allow adjustments. However, how you do this is specific to the saw. I suggest you go online to the manufacturer's website and find the manual for your saw.
Related Professionals
Dover Cabinets & Cabinetry · Highland Village Cabinets & Cabinetry · Oakland Park Cabinets & Cabinetry · Cypress Carpenters · Solana Beach Carpenters · Alexandria Flooring Contractors · Cartersville Flooring Contractors · Kansas City Flooring Contractors · La Mesa Flooring Contractors · Mansfield Flooring Contractors · Redlands Flooring Contractors · West Chester Flooring Contractors · Hilton Head Island Furniture & Accessories · Palmetto Bay Furniture & Accessories · Wolf Trap Handyman
eal51
17 years ago
Posting the make of the saw would help.

Your saw should have come with a manual that explains the adjustments needed to keep the saw in square.

When you get a manual for the saw, get a notebook and put the manual in the notebook. Store the notebook were you will know were it is.

Every power tool I own has a manual that I have catalogued. If I need to make an adjustment, I know were my manuals are and that they have the information I need to correct the problem.

Enjoy the journey.

eal51 in western CT
lkplatow
Original Author
17 years ago
It's a Delta saw - it was a Lowe's black Friday special a couple years ago. I have the manual and in it, it shows how to adjust the fence and the blade. It seems like either one of these would probably square things up, so how do I know which one is better?
User
17 years ago
I'd do the one that is the most easy.
marys1000
17 years ago
Could your blade either (1) bet a tad loose or (2) a tad bent? (FWIW I'm a total novice)
sombreuil_mongrel
17 years ago
The blade needs to be square in two planes: to the fence and to the table. The fence may have its own mounting/adjusting bolts. Failing that, the head unit bolts to the table, and the calibration is made there. If it is a non-compound saw, the blade/table relationship is usually determined by machining the aforementioned joint in the factory. If the saw has been subjected to kickbacks, the frame may have warped. In that case, brass machinist's shims would have to be inserted to bring it into calibration.
On compound miter saws, the blade/table angle is adjusted with a setscrew or bolt that acts as a stop to zero out the bevel.
Casey
lkplatow
Original Author
17 years ago
Just wanted to follow up and let you know that I was able to fix this - the arm had loosened up and had quite a bit of side to side play in it as you moved it down, and I think it was just not coming down straight. I tightened it up to eliminate the play without adjusting anything else and that seems to have fixed the problem. Thanks all!