Lehman Seismometer Parts

A Lehman Seismometer is probably the most common DIY seismometer design around. The basic principle is that of a sideways pendulum. A freely swinging arm with a mass at the end will move when there is ground motion from an earthquake, and a pickup coil converts that motion into current, which can be read by a computer or microcontroller like an Arduino. This design can be used to pick up horizontal (side-to-side) ground motion from an earthquake. If you want to pick up vertical (up-and-down) motion, you can probably modify this model, but you'd be far better off with the TC-1 Slinky Seismometer design that I've created parts for. (And it should be noted that these seismometers are best for picking up distant quakes. A strong local quake will overwhelm the device and will likely just shake it apart.)

These models are designed for use with 20mm 80/20 t-slot aluminum bars and half inch aluminum rods. The pickup coil and the magnet holders use #6 screws. The damper plate is a 2 inch square copper plate. The magnets are 2 inch by 1 inch by 1/4 inch rectangular bar magnets, held stuck on a 3 inch metal square that fits into the model. The weight is made up of a number of 1/4 inch bolts. The tuner key holder fits a guitar tuning key, and this is used for making fine adjustments to the support wire.

You will need to print the following:
2 Weight Disk
2 Plate Stand
2 Magnet Plate Set Screw
1 Lehman Wire Spool
1 Tuner Key Holder