Tarseam Bhullar from Vancouver British Columbia is the inventor of this repellant laser beam device that prevents pests from feeding on fruits in the field.

The laser beam sweeps the field in vertical and horizontal patterns, frightening the pest without blinding them.

I'm not sure if this invention will make it to the product stage, but I like the idea of using a low energy device like a laser that could easily be powered with a solar cell and rechargeable batteries.

The new plastic pivot point for the current do it yourself deer deterrent only lasted about 4 months before it broke.

I suspect  constant rubbing from the metal chain had something to do with this failure, maybe in conjunction with the freezing temperatures we've had lately.

My quick solution for the moment was to use some electric fence wire to secure the chain to the support arm until I can figure out a more long lasting and still economical way of reducing that friction.

You can read the first chapter of a new book called "Making Things Move" for free as a pdf download. Some information that looks like it could come in handy for the back yard deer deterrent experimenter.

Techlib.com has an intriguing circuit that might be of interest to some back yard deer deterrent experimenters out there.

It detects seismic vibrations from a person or large animal and then sets off a wireless doorbell buzzer for a few seconds to startle whover is nearby.

They label it as a deer repellant for the garden, but I would be concerned about the protective range this thing has. It might work for a garden with low level deer traffic and maybe just one entrance, but our large perimeter here would require dozens of these to cover the whole area. There's no data presented about testing on a real garden, so I would think twice about this approach before investing too much time in it. In fact I feel pretty confident you would get better results with my current design no matter what situation you have, but that's just me.

I've managed to solve the rotisserie motor friction problem by deleting the plastic case it comes in.

This means you now have to use some glue or epoxy to secure the support arm to the motor shaft. At first I was unsure of how long the glue would last due to the issue of gravity, but I've had the above deer deterrent going for almost 2 weeks now with no problems.


You'll need to cut the black plastic case in order to get the power cord out. The switch should just pop out. A coping saw worked for me, but I'll bet a hack saw would also get the job done. Be careful not to cut any wires or fingers.

I changed this one from a clanging sound to a booming noise in an effort to keep things mixed up.