A 5/16th hex key is the size I ended up using for the low budget do it yourself rotisserie motor backyard deer deterrent.

The trick is connecting this hex key to the rotisserie motor shaft holder in a way that it won't fall off.

You'll need to open up the motor case, which is just a few screws. Remove the shaft connector from the motor. Notice how it almost fits the hey key? Place it on a solid surface and force the curved end where a rotisserie shaft would normally go. Use a few light taps of a hammer to firm it into place. Test the connection by trying to pull them apart. If it's a bit loose add some heavy duty glue or epoxy. Mine seemed pretty well stuck and it's still holding without any adhesive.

The next step is to re-install the shaft holder onto the motor and put the case back together.

Now you're ready to start making some automatic deer deterrent noise and motion, which is what the next post will explain.

Rotisserie motors are readily available in a variety of shapes and sizes. Expect to pay anywhere from 20 to 30 dollars for a small unit and upwards of 150 dollars for the big ones, which might power a super large moving deterrent for extreme deer predation.


I've had this small one operating 24 hours a day for 2 weeks now.

Found it at a local Walmart. A recent visit reveals it might be a seasonal item.


The next thing you need is a large hex key. They usually come in a set, which helps make it easy to choose the size that fits your rotisserie motor shaft holder. I'll save those details for the next post.

I discovered this week that a low end rotisserie motor matched up with a large hex key can equal enough deer deterrent noise and movement to keep those sweet potato leaf munchers away.

The noise interval is decreased down to a frequency of 1 hit every 25 seconds, which I think works better than the more constant banging approach I've taken in the past.

Two rotisserie motors hacked up in this manner might be even more effective by allowing for an easy way to adjust the timing. You could simply turn one off for a few seconds and then back on to keep even the most confident deer guessing and on his toes running away from your garden.

Why are deer so active at sunrise and sunset?

The way I understand it one of the advantages a deer has is its ability to see in the ultraviolet range, which is at a peak in the early morning and late afternoon.

The next generation of my mechanical do it yourself deer deterrent will take into account this trouble window and somehow gear up to a higher noise frequency, but the details are still fuzzy.

Image credit goes to the informative deer management portion of the Fish and Wildlife site for Delaware.

Everybody knows that the best and most effective backyard deer deterrent is a well placed bullet.

I know there's still a thing or two I could learn on how to convert a backyard deer into dinner, which has promted me to put WM. Hovey Smith's new book on the list of books I want to read.

You might have noticed from my last post our local library only had a juvenile book on the subject, and although it covered some interesting subjects in regards to deer behavior, it said nothing about how to shoot and dress out a deer. This strikes me as odd because deer hunting almost seems like a religion around here. Perhaps when I hunt down a copy of Backyard Deer Hunting I'll donate it to the library after Anna and I devour it.

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.

I think I've decided these heavy metal lumber brackets are what's needed in the first stage of the back yard deer deterrent.

Folding the second stage tin in half provides the elastic spring that's needed to send the golf ball on its outer orbit.

It wouldn't hurt to add an LED light to the golf ball somehow to provide for more visible movement at night.

I decided my first attempt at making a do it yourself interval timer from one of these solid state units was worth another try, and then another one after that.

The units pictured above do about the same thing as the 32391 I tinkered with a little over a month ago.

I've still got this nagging feeling one of these can be modified to work as a functional interval timer, but I'm not sure what type of capacitor should be added or exactly how it would be wired to handle a 120 volt load.

This series of failures has prompted a completely new direction in regards to the locomotion behind the dc motor powered deer deterrent. This new design will provide a means to adjust interval timing without a complex circuit. Stay tuned for more details as the new prototype begins to take shape.

This is what your basic DC motor gearbox looks like. The gear configuration helps to slow it down and provide more torque than just the motor spinning by itself.

I ordered this one from a robotic supplier named Pololu. The cost was around 12 bucks once shipping is factored in.

The instructions that came with the kit are a challenge to understand. Luckily they have great illustrations to guide you in the right direction.

You can arrange the gears in a way that gives you 4 choices of speed.
                                                                                                
Consider this an advanced project. Those gears are small and you really need to get it just right for a smooth operation. It took me about 2 hours of messing with it to finally get some decent results. If you do order this kit you might want to add on one of their DC transformers for only 5 bucks.

If you've got an old computer laying around it might be possible to use it as a dedicated multi timer control center.

Timer 5.0.0 provides the ultimate control of up to 24 channels via 3 printer ports. The program enables your home computer to control relays, solenoids, pumps, or whatever you can imagine.

It's too complex of a solution for my tastes, but some of you out there might start with a timer for your deer deterrent and find out how much fun it might be to control your sprinklers and security lights once you've got the system in place.

I could see this also controlling an automatic chicken coop door by customizing each day's close time to account for the changing bed times through the year.