The MCRU PWC Record Stabilizer
The MCRU PWC record stabilizer design has its roots in a problem that arose 25 years ago in the age of making sensitive mechanical hard drives to save datastreams correctly under the vibration spectrum of a hovering military helicopter.
Tests were carried out to damp rotor frequency vibration using polymers supporting a plate to which the drives were fitted, and adjusting the mass of the plate until vibration at the rotor frequency (rotor rpm and number of blades) was successfully nulled. The combination of mass and polymer Shore hardness and density created a mechanical filter which absorbed the vibration effectively and was broader in spectrum than expected, due to the mass of the plate.