Everybody loves lasers, but sometimes they’re more of a gimmick than a useful guide. Miter saw laser guides help out a lot if the laser shows the edge of the blade — and they’re worse than nothing if the blade and laser aren’t aligned. If your miter saw isn’t fitted with a laser-site guide, chances are you can cheaply retrofit it with Harbor Freight’s laser arbor disc.
This laser disc fits next to the saw blade and projects a line on your workpiece where the edge of the saw blade will cut. The laser arbor guide activates at 500 RPM and uses three GP186 button-cell batteries. It measures 2″ in diameter by 5/16″ thick.
I spent $30 for an Irwin guide to find out it was 1/16″ off with no way to adjust it — but other people have reported good results with add-on laser miter guides. Fortunately, if this cheap-ass guide doesn’t work, you’re only out $13 — a hell of a lot less than a new miter saw with laser guide. Plus, if you wait, it goes on sale for $10 every now and again.