Shear generator

[DreamThinkBuild]

Hi All,

This idea was from helping my brother move, he had a 6ftx4ftx2.5ft table with about 200lbs of stuff on it. It took both of us to lift it but when setting it down I noticed the table could be easily wobbled back and forth with just the index finger. I was able to get about 1" displacement with very little input force before the table looked like it would buckle.

If it takes two people to lift 200lbs 1" off the ground yet it takes a brief nudge with an index finger to shear 200lbs 1" side to side. I thought maybe a generator could be made that just nudges a platform back and forth.

The design here is pretty simple, it's just a motor which runs a rotor with a raised cylinder. The beam has a modified skotch yoke modeled into it, there are spaces to allow it to snap back after pushing to maximum displacement. Two magnets side by side fit on the top of the beam. An outer frame holds the pickup coil. The motor was running at 13.7vdc @ around 2500 rpm.

The results for this model were interesting but not as impressive as some simpler models I have. I did manage to get a scope shot which is unloaded before I broke the pin off the rotor by trying to push the motor to a higher speed. It generates a triangle wave as it crosses the center line. I didn't get a loaded reading, I have to take it apart and fix the rotor.

I'm putting this up here for others that may want to expand on the idea or inspires something else.