Ok, here is how I do it. Without a blade installed, do whatever you must do to get your arm to the same measurement front to rear. Once that is achieved, that is where you want to leave it. When you install a blade, install it in the bottom clamp first. Then, pull down on the arm to take the slack out of it and install the blade in the top clamp. When you flip the lever that should apply the proper amount of tension. You can fine tune it a bit by turning the big black knob a bit CW. That applies more tension to the blade. Then, you can unflip the lever and take the blade out of the top clamp and insert it in a hole or leave it as is and just start cutting. As has been mentioned before, some of the EX saws will "unwind" the knob because of blade stretch or whatever. I took a large width rubber band and wrapped it around the threads of that tension rod and then stretched it down along the right side to one of the motor bolts. That keeps the rod from turning. I hope I have made myself clear.