Smart Insecticide Applicator for Livestock
Owner's Manual and Setup Guide
Thank you for purchasing the De-Fly. This controller is the brains of a walk-through fly sprayer built for beef cattle on rangeland. You build the walk-through opening to fit your place, supply the pump and plumbing, and the De-Fly handles the rest: it watches for cattle with an electric eye and gives each animal one measured dose of spray as it passes through. Your cattle treat themselves on their normal trips to water and mineral, with no gathering, no chute work, and no wasted chemical on a cow that decides to stand in the opening. This puts fly control on your herd every single day, whether you are on that pasture or not.
The controller uses a photo eye beam across the opening. When a cow breaks the beam, the controller waits a short adjustable delay so the animal is under the nozzles, then turns the pump on. The pump runs while the cow is in the beam and keeps running for a short adjustable time after the cow steps out, so the hindquarters get covered. Every animal gets exactly one dose per pass:
All timing is adjusted from your phone. The controller broadcasts its own WiFi signal, so it works anywhere on your place with no internet, no cell signal, and no app to download.
Nozzle and sensor mounts are sold separately so you can match them to what your opening is built from: round pipe, square tube, T-posts, wood posts, or flat steel. See the Mount Catalog and the "Nozzle and sensor mounts" line in the list below.
The controller will run any 12 volt pump and any nozzles you plumb to it. Build it the way that fits your place. A recommended parts list is in De-Fly-Recommended-Buy-List.html and will grow as we add to it. Nothing on that list is required.
The shortcut for tank, pump, and hose is one trip to Tractor Supply for a 12V spot sprayer package.
| Item | What to look for |
|---|---|
| 25 gallon 12V spot sprayer | CountyLine or WorkHorse 25 gal. 12V Spot Sprayer, in the sprayer aisle. This one purchase covers the tank, the 12V demand pump, and the hose. You will not use the spray wand; the hose tees off to your nozzles instead. The 15 gallon version works too for smaller herds |
| Spray tips and nozzle bodies | Whatever you already like, or the recommended TeeJet set on the buy list: two 19349-211-406-NYB single bodies, one 19350-212-406-NYB through-body with check valve, and three 25598-3-NYR caps. Then pick the tips that snap into those caps |
| Hose tees, barbs, and clamps | Sized for the sprayer's hose, usually 3/8 inch. Sprayer parts aisle |
| Nozzle and sensor mounts | Printed mounts from us that hold the nozzle bodies and the photo eyes on whatever your opening is built from. Pipe Clamp for round pipe and tube gates ($22, or $26 for 2-3/8 and 2-7/8 inch pipe), Square Tube Clamp ($20), Strap Mount for any round post or wood post ($18), T-Post Mount ($24), Flat Mount for flat steel or boards ($12). Each comes in a Straight version, an angled version for vertical posts, and a Sensor version with a 3/4 inch hole for the photo eye. A typical walk-through uses three nozzle mounts and two sensor mounts. Pictures and sizes are in the Mount Catalog; clamp hardware is on the buy list |
| 12V battery | A lawn and garden or deep cycle battery from the battery aisle, 18 amp hours or larger. A worn-out truck battery that still holds a charge will also run it |
| Solar battery maintainer, 10 watts or larger, with charge controller | Automotive aisle. This keeps the battery topped off year round. The controller draws about 1.5 amp hours per day plus a small amount for each spray |
| Inline fuse holder and fuses | Automotive aisle. Goes on the battery positive wire. Size the fuse a little above the pump's rating. The 1 GPM spot sprayer pumps do well with a 7.5 amp fuse |
| 16 gauge wire and zip ties | Automotive aisle, for the runs between battery, controller, and pump |
| Posts, panels, or pipe for the opening | Fencing section, or use what you already have. See the layout section below |
Budget roughly $250 to $350 for the full list, with the spot sprayer package as the biggest piece, plus about $100 for a set of five mounts and their clamp hardware.
Place the walk-through where cattle funnel themselves every day: the trail to the stock tank or pond, the opening into a water lot or mineral feeder, or a fence-line gap between pastures. On rangeland, water and mineral traffic is the one place the whole herd shows up on its own, so that is where the sprayer earns its keep. The opening should be wide enough for one animal at a time, about 30 inches, so cattle pass through single file and the eye counts them one by one. Fencing a small trap around the water source with the walk-through as the only way in works well.
This is the most important layout decision. Mount every nozzle along one side of the opening, not both. Cattle pass through the opening in both directions during the day. With nozzles on one side only, an animal walking in gets treated on the flank facing the nozzles, and when it walks back out later, the opposite flank faces the nozzles and gets treated on that trip. Over a normal day of coming and going, the animal gets full coverage without getting double dosed on every pass. Nozzles on both sides would soak both flanks every single trip and burn through chemical twice as fast for no added control.
The included angled brackets take the guesswork out of aiming. Mount one bracket low on the rail, about knee height, so its nozzle sprays up at 45 degrees and coats the belly, underline, and inside legs. Mount the second bracket high, above back height, so its nozzle sprays down at 45 degrees and coats the topline, shoulders, and far side. If you run a third nozzle, mount it at flank height spraying straight across. Between the upward and downward fans, the animal walks through a full curtain of spray.
The De-Fly ships with two photo eyes so cattle are caught coming and going. Mount one eye a step outside each end of the nozzle run. Whichever direction an animal enters from, it breaks a beam before it reaches the first nozzle, so the spray is already running by the time it is under the nozzles. The animal will not be sprayed a second time at the far eye on its way out. The controller gives one spray per pass and does not reset until the opening has been empty for the re-arm time.
The controller has labeled terminals. All connections are 12 volt. The pad-by-pad diagram is De-Fly-Wiring-Diagram.html.
| Terminal | Connect to |
|---|---|
| BATTERY + | Battery positive, through the inline fuse |
| BATTERY - | Battery negative |
| PUMP + | Pump positive wire |
| PUMP - | Pump negative wire |
| Photo eyes | Both eye cables are pre-wired to the controller. Just mount the eyes and reflectors |
Connect the solar panel to the charge controller, and the charge controller to the battery, following the charge controller's own instructions. The De-Fly connects to the battery, not to the charge controller's load terminals.
The controller broadcasts its own WiFi signal. There is no app to install and no internet needed. Scan these two codes with your phone's camera, in order:
Step 1: Join the sprayer's WiFi
Scanning connects your phone to the DeFly network automatically
Step 2: Open the control page
Scanning opens the controls in your browser
If scanning does not work: join the WiFi network DeFly with password spraycow, then open a browser and go to 192.168.4.1. Your phone may say the network has no internet. That is normal, stay connected anyway.
| Setting | What it does | Factory setting |
|---|---|---|
| Start delay | Wait after the beam trips before the spray starts, so the animal is under the nozzles | 0.5 seconds |
| Spray after clear | Keep spraying this long after the animal clears the beam, to cover the hindquarters | 1 second |
| Max spray time | The longest the pump can run for one animal, even if it stops in the opening. This is the limit that keeps a parked cow from draining your tank | 2.5 seconds |
| Re-arm time | How long the opening must be empty before the next animal can trigger a spray | 2 seconds |
| Trigger delay | How long the beam must be blocked to count as an animal. Raise it if tails or birds set it off | 150 ms |
The sequence for each animal: the beam trips, the controller waits the start delay, the pump runs while the animal is in the beam, the pump stays on for the after-clear time once it steps out, then shuts off. The control page also shows a live head count, both since the last power-up and lifetime, so you can see how much traffic the sprayer is getting.
Always test with plain water before loading chemical.
Oil-based and water-based livestock sprays both work with a standard diaphragm pump. Flush the pump, lines, and nozzles with clean water after each tank and before storage.
| Problem | What to check |
|---|---|
| Nothing happens when cattle walk through | Check the control page. If the Beam line never shows BLOCKED, re-aim the photo eye at the reflector. If the page says SPRAYER OFF, turn it on |
| Sprays when the opening is empty | The eye has lost sight of its reflector. Re-aim it, clean the lens and reflector, and make sure nothing is swinging in front of it |
| Pump runs but nozzles barely mist | Clogged nozzle or strainer, kinked hose, or low battery. Clean the nozzle tips and check battery voltage |
| Tail swishes or birds trigger it | Raise the Trigger delay setting to 300 to 500 ms |
| One animal gets sprayed twice | Raise the Re-arm time so slow cattle fully clear the beam before it re-arms |
| Cannot find the WiFi network | Disconnect and reconnect the battery, wait 30 seconds, and stand within about 50 feet of the controller |
| Battery keeps going dead | Check the solar panel is in full sun and the charge controller shows charging. A 10 watt panel or larger is recommended |
No. The two eyes exist so cattle get caught coming from either direction, and the controller treats them as one detector. An animal breaks the near eye, gets its one spray, and walking past the far eye on the way out does nothing, because the controller does not reset until the opening has been completely empty for the re-arm time. One pass, one dose, either direction.
No. The controller makes its own WiFi signal that your phone connects to directly, standing near the chute. It works anywhere on your place.
There is no limit. Cattle walking through single file each trip the beam and each get their own dose. The head counter keeps up with all of them.
It gets one dose, capped at the max spray time, and nothing more. The controller waits until the opening is empty before it will spray again.
Mounting the photo eye at cattle chest height, about 24 to 30 inches up, lets most dogs pass under the beam. You can also raise the trigger delay so quick movers do not register.
Yes, every animal that trips the beam gets the same spray timing. If small calves are passing under the beam height, they will not be sprayed at all.
About 1.5 amp hours per day for the controller, plus a small amount each time the pump runs. A 12V deep cycle battery with a 10 to 20 watt solar panel will run it indefinitely.