How do spraying drones work?
It’s almost as if drones were invented for spraying – they really have some amazing benefits and physics over other traditional methods of spraying. The spraying drone has an on-board tank, pump and nozzles (usually either out on a boom or under each motor). The drone might be powered by batteries or by a gasoline / hybrid engine. The operator flies over their field, usually by a fully-automated system called the Ground Station, and the downward thrust of the propellers pushes the spray down into the crop. Generally the drone is only 9-12 feet (3-4M) above the crop, so the turbulence from those props really helps to ensure the spray coverage is consistent and thorough. So whether it be banana trees, sugar cane, fruit orchards or a more traditional row crop- the benefit is that you get better penetration through that crop / canopy than traditional methods which lack that downward turbulence.
What makes spraying drones so effective?
Answering this really depends on what you are using your crop spraying drone for. Maybe the benefit for you is that you are spraying a crop that is challenging to spray with traditional means. Some of those could be:
-Terrain is too steep or rough for a tractor or manned Ag plane
-Soil compaction concerns
-Fruit-drop from disruption by a tractor, like blueberries
-Foliage is dense and hard to penetrate, i.e., bananas, sugarcane, or other nut/fruit trees
-Lack of local Ag plane
-Crops usually treated by a backpack sprayer
There are also times where the traditional method is just too time-consuming, (i.e., spraying with a backpack) or the process to getting to the site is dangerous or hard to reach. Let’s face it… a spraying drone is flown automatically. So instead of you or your laborers drudging through a field in PPC under the hot sun, you program a flight, hit a few buttons and sit back while it does all the work. Sounds like a way better workday, huh! Hard to reach places with marshy environments or other restrictions might be easily avoided by flying above! You aren’t restricted by what’s happening on the ground.
What we know so far is that drone’s are a highly effective tool for spraying. And not just crops, but roofs, mosquitoes, de-icing windmills and beyond. The super-low operating costs (about $7/hr), low maintenance and affordable entry price (starting $3499) makes spraying drones one of the fastest growing sectors for the drone industry. Plus, with on-board GPS, terrain sensing, and automatic sprayer control, you get a reliable and repeatable application. Drift can be mitigated with larger droplet/nozzles.
How much time you will save will depend on your application rates but we have a calculator that will help you estimate that!
How much research has been done on spraying fields with drones?
Crop spraying drones have been around for more than 20 years; that’s a short-time in comparison to planes or ground rigs, but it’s not necessarily “new” either… there are literally tens of thousands of these machines flying around the world and the market growth year over year is astonishing.
HSE is leading the efforts when it comes to research. We work directly with the USDA for pattern and efficacy testing. We also partner with the nation’s leading Ag universities and chemical companies to continually expand our knowledge and the future of the tech. The testing results from the USDA show that the spray coverage uniformity is very good (despite what you might think with all that turbulence), that canopy penetration was strong and our larger aircraft swaths were nearly 40 feet (12m)! You can find the testing report HERE with a formal research paper coming out later this year.
Additionally, the USDA is currently working on a spraying efficacy study which you can read about HERE
Is it legal to fly spraying drones?
Yes! Totally! Depending on the size of the drone (over or under 55lbs), there are specific approvals you’ll obtain. At first, the process was pretty slow as the regulator’s had to figure out their process and learn about the technology. This is getting smoother with every application (woohoo!). You can learn more about the process in our BLOG post.
We offer FAA Drone Approval consulting and can help you when-needed or take care of the entire process for you. Just get in touch with us to learn more.
Even with your FAA drone approvals, you still need to learn how to fly… the better the pilot, the more efficient you’ll be. We discuss the regulations in our Flight Training Class.
How about other countries? In most countries, flying spraying drones follow a somewhat similar process as in the USA. You can do some searching online or contact your aviation authority to find out. We might also have a Dealer in your area who knows the rules, contact us to learn more.
How much do spraying drones cost?
As you might expect, the price varies largely by capacity and features. Our smaller drones start around $3,000 USD and our larger drones start around $18,000. These include the common parts like the aircraft, full GPS autopilot, fully-automated spray system, remote controller, ground station software and shipping case or cartons. Some things that you’ll need in addition are batteries & charger(s), perhaps spare parts and of course professional training… you will likely see a very fast return on investment (ROI) with these very low purchase prices.
Can spraying drones replace traditional planes or large ground rigs?
This is a great question that we are asked frequently. And in short- it depends! We first look at application rates for your chemical. When the label requires hundreds of gallons per acre or hectare, a large ground rig or manned ag plane is a much better fit. For the time being (based on current battery technology), spraying drones are really best for Low Volume or Ultra Low Volume (ULV) labels… these make the most use of spraying drone capacity. However, some customers might not have a local manned ag plane available, or perhaps the terrain is too difficult for a tractor – or maybe there are other limitations with traditional means. In these cases, a drone could make a lot of sense. Even if your application rate is a bit higher, perhaps more frequent ‘fill-ups’ are still more efficient than other options. …Keep reading to find out about how many acres you can cover in an hour.
What industries are using spraying drones?
We love this question! Because there are so many, and it is growing every day!
The most popular continues to be agriculture for crop spraying. Traditional row crops but also trees, nurseries, vining crops and beyond. We also are seeing more companies wanting to spray moss / roofs with drones. We see work for clearing vegetation (right-of-way management, railways, utilities), and even people looking for de-icing!
Is it better to have a helicopter or multirotor? What’s the benefit with having 4, 6 or 8 rotors?
Think about it this way, your coverage benefits by a wider area where air is being pushed down by rotors. So generally, 4-rotor (“quadcopters”) or helicopters have a more narrow swath and cover less area. Although those platforms might get a few extra minutes (because there are less rotors to turn), the extra flight time probably doesn’t equate to the wider swath. So our experts suggest the 6-rotor is the ultimate configuration for a few different reasons:
- The safety benefit of having motor-failure protection… if one motor fails, it can still safely land, whereas a quadcopter will likely fall from the sky… not good when carrying potentially hazardous chemicals.
- 6-rotors feature a smaller footprint (versus an 8-rotor), while still achieving a nearly perfect power-to-weight ratio. This maximizes your flight time.
- 6-rotors have a bit less maintenance and might be easier to transport than an 8-rotor; just think of it, two less motors and props to deal with and their fewer rotors means the frame can be a bit smaller making it easier to carry.
What nozzles come with the drone?
One of our most popular questions! First, these nozzles are our generic / standard nozzle, but as the next question asks: yes, you can replace them for larger nozzles to meet label requirements or minimize drift when needed. These nozzles are standard off the shelf and are not proprietary – important so that the drone can really evolve with your needs over time.
Standard Nozzle (adjustable by user)
M4E (5L) 2x 110-015
Pump Rate: 5L/min
M6E-1 (10L) 2x 110-015
Pump Rate: 3L/min
M6E-X (10L) 6x 110-015
Pump Rate: 3L/min
15L (M6A Pro) 6x 80-005C
Pump Rate: 3L/min
20L (M8A Pro) 6x 80-0067C
Pump Rate: 5L/min
Can you change nozzles (or pumps) to meet your label requirements?
Yes! You can also change the pump – these are standard off the shelf items so that the drone can really adapt to your needs. There are a few simple aspects to consider when changing nozzles. The first is can the standard pump provide the pressure for your desired nozzles? Our pumps range from 50psi to 100psi. The second is to account for the tank size and finding an optimal balance between your tank being emptied and your batteries running out… it will really help your efficiency if you can time those closely or at about 40% of the other so you can swap batteries every-other tank fill-up. We have some customers who have changed the nozzles to a single broadcast, or even moved them to the front of the aircraft to spray roofs. There are a lot of ways to utilize these aircraft!
If you have any questions about this, just ask!
What about drift?
Very important question! You’ve probably seen a lot of videos where the spray from a drone is going everywhere! Well if you’re using a fungicide or insecticide, maybe that isn’t so bad – but a systemic herbicide is a different story. We’ve found during our testing with the USDA that changing out to a larger nozzle (air induction is also beneficial), we were able to significantly reduce drift while still producing a great spray pattern. Be sure to check out the Efficacy Study that the USDA did!
How do I achieve the application rate?
How much area can you really cover?
Is it easy to fly a spraying drone?
It is easier than most people think! Our advanced commercial-grade autopilot systems are designed specifically for spraying missions. This is a very important benefit because the way a drone flies for spraying work is quite different than doing camera or other drone work.
Our drones are also 100% automatic, or can be flown by remote control with GPS assistance. The stability, reliability and ease of use make your job easier and maximizes efficiency.
There are three ways you can operate your drone:
- Mission Planning: This is the most common and efficient way to spray an area. You begin by outlining the corners of your field on our Ground Station App (it uses Google Earth and other INTL map interfaces). You then add any obstacles in your field by dropping pins around the object. Next, you confirm your desired swath, speed and altitude and the software automatically fills in the individual rows! A few clicks and the aircraft launches, flies the course, comes back and lands.
- A-B Mode: This is a super-fast and great way to conduct simple missions for areas that are generally square in shape (or smaller areas). You use the remote controller (RC) to fly the drone to the bottom corner of the intended area to spray, you flip a switch on the RC that records that corner as “Point A”. Next, you fly to the opposite end (same row) of the field and flip the switch again, its recorded as “Point B”. You then move the RC stick to the right, if you want to fly to the right, or left, etc. The drone continues the pattern over and over until you stop it. During the flight, you can shorten or extend either end of the row by 3ft (1M) increments.
- Remote Control: Lastly, you can fly the drone manually by the RC. This is common for spot spraying, or for people who wish to manage the mission in a more manual fashion.
What about maintenance for the drone?
You’ll love this, because there isn’t much to it!
Essentially, you have brushless motors, batteries and carbon-fiber parts. Like all electronics, they work best when they can ‘breathe’, that means it is advised to keep motors and electronics generally clean – do this by using compressed air. You could do this monthly, or more often if you often fly in dusty environments.
The standard maintenance items are replacing propellers as they get dull over time, and batteries as they slowly hold less and less charge over time. On average, we calculate maintenance costs for all items plus a few extra spare parts (just in case!), to be between $7-$10 per hour! And realistically, you’ll probably spend less than that 🙂
Are they waterproof?
How fast can they fly?
How high do you fly?
How wide is the swath?
What is the difference between nozzles on a boom or under the motors?
What happens when the drone runs out of chemical?
How do you know how much chemical is left?
How does the automatic spray control system work?
Who do you recommend for Drone Insurance?
We’re excited to see more and more insurance companies offering competitive and comprehensive drone insurance. Some companies offer “pay-per-flight” plans and full-coverage options as well! Check with some of these providers for whatever you might need:
Who do you recommend for drone leasing or financing?
What about using adjuvants?
As the applicator, it is ultimately your decision. Our opinion (on the science/research) is that you can effectively control the application by choosing the right nozzle type & size for the job.
Would the drone have any issues using an adjuvant sticker or spreader? Probably not, but we haven’t done any specific testing on this.