I just purchased a Dewalt DWS715 miter saw. I have never used one in my life, so naturally I am carefully reading the entire manual (here) first.
There is "miter lock knob" which securely locks the miter adjustment in place (note that this is in addition to the detents at various angle which also to some extent fix the miter, though less securely). On page 4 of the manual, it says to lock a handful of various lock knobs before transporting the saw. Then it says:
WARNING: The miter lock knob should be used only when carrying or storing the saw. NEVER use the lock knob for any cutting operation.
I thought this was weird when I first read it. Now I've got further in the manual where they describe actual cutting, and there are multiple places where it makes it sound like you should use that lock knob when cutting, which seems like a direct contradiction to the above. On page 6, explaining how to set your miter:
Miter Control (Fig. A) The miter lock knob 5 and miter detent latch 6 allow you to miter your saw 50° left and right. To miter the saw, unlock miter lock knob 5 by rotating the knob counterclockwise, squeeze the miter detent latch 6 and set the miter angle desired on the miter scale. Lock miter lock knob by rotating clockwise until tight.
And on page 7, explaining cutting operations:
Miter crosscuts are made with the miter arm at some angle other than zero. This angle is often 45° for making corners, but can be set anywhere from zero to 50° left or right. After selecting the desired miter angle, be sure to lock miter lock knob. Make the cut as described above.
I am going to assume that I should tighten the miter lock knob before every cut. Correct? Any idea what the bit on page 4 is trying to say?