Resolving Crooked Cuts Lesson #3

By Larry Anderson
Technical Advisor

The crooked cut problem has not been solved and we have checked for loose guides and guide arms that are not square to bed of the saw and found that this is not the problem. We have yet to remove the blade from the saw and it is time to think about tension.

Analyze Blade Tension

Is the saw automatic or is it manual? For manual saws, it is possible to see if the operator is turning the handle properly to achieve proper tension. The proper tension on most saws is 25,000#s. But, without a gauge it is impossible to tell when 25,000#s has been reached. It is commonly assumed that if you over tension a blade it will break or at the very least the tensioning will pull the blade apart at the weld. This is quite impossible. The tear strength of a 1" wide blade is approximately 220,000 #s and since most screw mechanisms will wreck the saw before they could ever tighten even to 30,000#s this would never be a problem. Some small saws will even be bent in the beam arm if they are tensioned even to 25,000#s. When we check the guides we felt that the blade was firm, so this is good enough to rule out tension failure.

So what is this all about?

Think about the tension. If the tensioning handle looks okay and in the case of hydraulic tensioning, the hydraulics are working, then probably tensioning is not a problem. But be aware, an un-tensioned blade will give crooked cuts.