Deer deterrent back up failure

I started this deer deterrent project with a medium sized box of advertising display motors. Not the optimal set up, but I was determined to find a use for these motors because I've carried them from a few locations for the past several years.

It solved the problem right away, but some of the motors would only last a few weeks. The longest I had one of them going was around 4 months before it burned out or one of the plastic gears within the drive section broke or wore down.

Now the box is empty, which has motivated me to come up with a new design that uses a pendulum movement. More on that in the near future.

In the meantime I rigged up this mini compressor to funtion as a desperate stop gap measure. Someone gave it to me a few months ago thinking I could use it for something like this. It made a moderate noise that was a weak substituition due to the lack of movement. Long story short it only lasted about a week before the motor burned up. I thought I could make it last longer by bumping down the voltage from 12 volts DC to 4.5 volts DC. I guess it was worth it due to the device being junk at the time, but I wouldn't do it again.