If it is a tee shank blade type jig saw, you may not have the blade fully seated. I have the Milwaukee jig saw and I really have to look at the blade to make sure the blade is full seated and perfectly straight to the saw. If the blade is not straight, I pull it back out and kinda re-twist it in until the blade seats straight. Make sure the blade is in the middle groove on the blade support wheel.
Make sure you are not influencing the saw with any kind of side ways pressure, let the saw do the cutting.
Last edited by Davet; 03-11-2008 at 04:27 AM.