There are a lot of videos and articles out there on how to improve the
accuracy of a miter saw. The best one – by far – was written by former
finish carpenter and Collins Coping Foot inventor David Collins for ThisIsCarpentry.
It’s a lengthy process that will pay for itself in spades quickly,
especially if your saw isn’t already in near-perfect tune (if you’ve
never adjusted it chances are it’s not as accurate as you think).
Fine-Tuning a Miter Saw
