1. Testing the Viability of the Magnetic-Oscillatory System
Before actual assembly, we had to test if our magnets could actually support the mass of the bath. To test this, the mass of the bath was measured and used as the target mass for the magnets to hold. To find the perfect distance to force ratio for the setup, the K&J magnetic calculator was used to estimate the forces. Because our apparatus called for a disk magnet and a ring magnet, and K&J’s magnetic calculator only provided the repulsive force between two magnets of the same type(i.e., ring on ring or disk on disk), two data sets were collected, one for a disk magnet repelling a disk magnet, and one for a ring magnet repelling a ring magnet. Then, the theoretical magnetic repulsion required was plotted (See Above) to determine the viability of the magnetic-oscillatory system. Because the plotted magnetic repulsive force was between the other two lines, we decided the system would work as the disk v ring would be somewhere in between. Then, we could move on to build the system.
2. Determining Shaft Length
It was important to get this right because the shorter the shaft, the less preloaded mass on the system. We found the total shaft length would be equal to whatever the distance between the magnets would be plus the height of the thread which was used to connect the bath to the shaft, the height of the inner magnet, the height of the ring magnet, and the height required between the ring magnet and the oscillator due to our mounting solution for the ring magnet (see right). Because we could not precisely calculate the distance required between the magnets, we simply added a 20mm safety net to ensure room for adjustment of the ring magnet and increase the torque which the ring magnet would have on the shaft. |