Tips for Tricky Saw Cuts

The other day we had to section a 24 inch diameter gas pipeline for metallurgical analysis. When we clamped it in our Marvel vertical bandsaw we saw some dynamic oscillations as we cut through the top section. This is because we basically had a cantilever beam with the fixed end in our vise and the free end at the top. In order to reduce the oscillations we clamped two heavy bridge clamps (about 10 lbs each) to the top making a simple tuned mass damper (without the tuning); it worked like a charm. We also added a 2×4 so the part would stay together after the cut went through the pipe. By hanging the 2×4 slightly off the end of the cut, we could cut through the pipe but still have the structural support of the 2×4.

Remember when machining, mass and rigidity (stiffness) matter.