Folkfreak, I took a powerful magnet to the weigh pan of my digital VTF scale, and there was zero attraction of the magnet to the weigh pan or even to the body of the scale itself. Seems that even though your plastic-bodied scale and my metal-bodied scale look alike (maybe exactly alike), there actually was a good reason why mine cost more money, other than the metal outer shell. For once in my life, my extravagance paid off.
nrenter and brf, You both got it right for the wrong reasons. My physics professor in college would have given you both an "F", but he was mean. The force of gravity never changes. What changes is the magnitude of the force vector in the vertical direction, when you rotate the tonearm in a vertical arc away from or down towards the LP surface. The magnitude of the vertical force vector due to gravity changes because you are shifting the center of mass toward the pivot (if you raise the tonearm) or away from the pivot (if the arm wand moves toward the LP surface). It's like a seesaw. When you raise the tonearm, some of its mass is shifted toward the pivot and thus the pull of gravity on the cartridge is partly borne by the pivot, not the cantilever, during that moment.