Maker and amature earth scientist Thomas Schrantz wanted his own seismometer device but was unable to find any low cost options. He eventually found plans for the low cost TC-1 Seismometer that used a simple Arduino interface and of all things a Slinky. He decided to improve on the design using 3D printed parts and some nylon threaded rods for support. You can find out more about the Slinky Seismometer at: http://3dprint.com/70679/slinky-seis...r-san-andreas/