If you’ve got a miter saw, compound miter saw, or a sliding compound miter saw, you may have experience with trying to cut quickly, using a laser as a guide, and the cut being off a little bit.
This is a common problem and means you need to make an adjustment on your laser.
The fact is, if the laser is not adjusted perfectly, it may as well be left off completely. It’s kind of like what Ricky Bobby’s daddy said, if you ain’t first, your last. If the light doesn’t work perfectly, that doesn’t mean it only kind of works, that means it’s completely useless!
So I’m going to give you a few tips on how to make adjustments and get your laser set up quickly and accurately.
How The Laser Is Supposed To Work
First off, you need to understand that most miter saws’ lasers are designed so the line is not cut off. In other words, the laser is just to the left of the kerf, just touching the cut.
This actually makes it really easy to set up quickly and use accurately. You just have to draw your cut line, then line that up with the right edge of the laser beam, and that will put your mark on the left edge of the blade.
Just keep in mind doing it this way means the waste of the board must be to the right of your mark.
Now Let’s Make It Perfect
Different saws required different tools for adjustment. But let’s assume you have that figured out and you have the proper tools in hand.
And just a reminder – Always wear your safety glasses when using your power tools! So if you don’t have them on already, put them on right now! You only have 2 eyes in this life, they are precious and you should take care of them.
The Process
Now you want to take a scrap board, preferably one that is flat and has a nice straight edge you can put against the fence.
Now use the miter saws hold-down clamp to clamp that board in place, leaving plenty board on either side of the blade.
If you do not have a built-in hold-down clamp, you can either use a quick-clamp to hold the piece to the cut bed.
Another option, which I would strongly suggest if you don’t already have one, is to build a miter saw workbench. This will allow you to set up custom jigs, gauges, extended fences, custom clamp-downs, and anything else you may need for making great miter cuts.
For more on this, check out How To Build A Miter Saw Table.
Now with the piece clamped in place, you want to start the saw and make a slight cut into the board. No need to cut all the way through.
Now return the blade to the upright position and unplug the saw. Safety first!
With the slight cut made, you can now see the exact cut line the saw blade makes for every cut.
So without letting the board move, adjust your laser so it just touches the left side of that cut.
Pro Tip
If you saw’s laser beam travels left or right as you lower the blade, that’s ok – don’t throw it out just yet!. You just need to adjust it so it’s accurate with the blade fully upright. Then in use, line up the cut with the blade fully upright and then ignore the light as you lower the blade to make the cut. We’ve all had to work with defective or cheap tools and instruments. The best of us learn how to use these tools, not make excuses as to why we can’t.
And that’s it! Make sure the laser adjustment is tightened back up snug, and go ahead and make a few test cuts with the board you already have sitting there. Just make your mark, line it up with the laser beam, and cut.
After the cut, inspect the board and make sure the blade didn’t cut off too much or too little. If it did, go ahead and make another slight adjustment to fine-tune it.
This may make the process a bit longer, but remember, once it’s set up, you’ll save time with all future cuts. So it’s worth spending a little extra time on right now to get it perfect!