They say that you can raise and lower the arm with the upper arm adjuster(knob at the back) to use a different part of the blade. This is from the manual:
"This saw has an adjustment knob K in the rear that can raise the blade mount up to 1†(25 mm). This allows you to fine tune blade tension when needed, as well as to reposition the saw blade at a point where you can use a different part of the blade in the cutting area. This also allows you to use a piece of band saw blade, cut to a length of 5â€- 6†(127-150 mm) in your saw, and gives you up to 3 inch cutting capacity when needed.
Note: Do not over tension the knob as this can cause premature wear and damage to the machine."
I have also read that it is best to leave the arm level, that's what I do.