• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
Pumpkin drop event

Long distance flying for 15min, how to do it?

#1
So I proposed a feasibility study for a food delivering drone in my home city (not in the US but somewhere in SE Asia), and wondered what would be the cheapest (budget is 200 dollars) twin engined rc setup?

Here are my goal specs:

-two 10 inch props (I wanna know the kV of the motor used)
-500g of payload
-(I want to know how many batteries should I use)
-Arduplane
-4 channel (Throttle, Roll/Pitch, Dropper)

Also during the RTL command the engines will be running at 25-45% power to conserve.

Do note that this is my first time into the RC hobby, but I have some knowledge after two years of watching FT videos. Thanks guys!
 

clolsonus

Active member
#2
I don't know if there are a ton of uav people on this forum, but I also don't know of a better place to ask this question either. We have been operating the X-UAV Talon for a couple years now and are pretty pleased with it's capabilities. It is relatively efficient, inexpensive, well engineered, has a big payload area, is pretty easy to hand launch, and can belly in to a lot of semi-rough places. We do aerial surveys so we aren't going long distances away from us, but we do cover a lot of ground within line of site. Our camera payload is about 500g (sony a6000 mirrorless camera) and we can comfortably achieve 1+ hour flight times on a 8000mah 4 cell battery. Our longest flight so far is 77 minutes on that amount of battery. Battery life depends on how aggressively you run the throttle which depends on your target cruise speed. 25-30 kts (maybe 12-15 mps) is a pretty comfortable easy cruise speed for this airplane at < 1/2 throttle.

There are many ways you could do this and many other aircraft available that might work out ok ... I'm not here to tell you what's best, just hopefully to get you thinking about the different important factors to consider.

There are also many ways to engineer (verb). I would recommend you start smaller and work your way up. You'll need someone that is a fairly competent RC pilot (or you will need to gain these skills yourself.) Like any other skill, it's just a lot of practice and patience to gain the experience. You'll also need to gain experience with the ardupilot (or px4) if that's what you choose to use. Some of the learning curves you will encounter will be pretty steep. There is no end to the unexpected mistakes we all can make that will crash the plane. Some things are just obvious to people that have been doing RC for 30 years and we don't even think twice about them, but they can be completely non-obvious to a person setting up a plane for the first time.

For example: CG (center of gravity, or where the airplane balances) is critical to have correct or the airplane won't fly well or at all.

Workmanship matters (imagine a sloppily folded paper airplane competing against a very carefully and precisely folded paper airplane ... even with identical paper and identical design ... which would you put your money on?)

For UAV's especially, quality components matter. A failed servo or receiver can quickly crash your airplane. A typical hobby plane might do a few (or a few dozen) flights a year where each flight is 5-10 minutes. There are exceptions -- some people fly a lot -- but I bet for most people and most of their aircraft, if you added up total flight time over a year (in minutes) it wouldn't be very much. Compare that to a production UAV -- if you are doing multiple deliveries per day, you could be racking up hours and hours every week. Also the consequence of a servo failure in a light foamboard airplane in your back yard is much different than a UAV doing real work and your business and reputation depending on it.

Prepare for crashes. People don't like to talk publicly about their mistakes and failures, but the attrition rate of fixed wing UAV's is typically very high. You should plan to be building up the replacement before you even get the original in the air for the first time. You might go through a 1/2 dozen airplanes before you get close to accomplishing something like your original plan.

From a business standpoint, don't forget about weather. Consider what weather conditions you need to safely fly and how often the winds in your area might exceed safe limits ... or how often it rains, or how much of the day is shut down to a thunderstom threat, etc. I live at a fairly northern latitude where we can literally go weeks at a time during the winter with no flyable days.

So my recommendation is to start small and inexpensive and build up slowly towards your ideal system as you learn and have successes. There is a lot to learn and a lot to consider beyond the basics for RC flying. But it also can be a lot of fun and extremely satisfying to achieve a successful "production" flight. There will be setbacks along the way that will feel like you got sent back to the starting point with nothing to show for it. Just be patient and have a long term focus.
 
#3
I have been building random gliders out of folder cardboard and bamboo sticks, so I have an idea about CG placement. Peep this, I might be following the style of the Sea Duck wings, but with a thinner camber and a slightly shorter chord.

But let me ask though, at what kV are your motors rated at?
 

clolsonus

Active member
#4
We are flying the e-flite power 25 (but I can't remember which exact kv version.) It's around 1000kv. The Talon actually gives motor/esc/prop recommendations and those are a good starting point. I believe we are flying a 12x5 folding prop. The folding prop is nice on landing so we don't catch the prop in the grass and bend a prop shaft or break a prop blade.
 

clolsonus

Active member
#6
Ideally you would find a local source so it would be easy to get parts and replacements as your project progresses. If you order internationally, your google luck is probably as good as mine.
 

clolsonus

Active member
#8
I don't want to endorse a specific vendor or a specific airframe, but bang good usually has the Talon in stock. i still wish there were more people interested in putting ardupilot/px4 into FT foamboard designs. My university lab has our own in-house uav autopilot (flight controller) board that I like to use but it is a bit larger than the pixhawk so space is more of a concern with most of the FT designs.
 

Hai-Lee

Old and Bold RC PILOT
#9
I don't want to endorse a specific vendor or a specific airframe, but bang good usually has the Talon in stock. i still wish there were more people interested in putting ardupilot/px4 into FT foamboard designs. My university lab has our own in-house uav autopilot (flight controller) board that I like to use but it is a bit larger than the pixhawk so space is more of a concern with most of the FT designs.
If you could you should consider the starting of a survey Drone, (fixed wing), thread as there are some on the forum who are getting seriously into survey drone design and building.

In my case there are a few gaps in the market still especially in the range Vs size Vs cost. This is the area I am working in trying to widen the design criteria away from the old RC thinking and design principles to a different approach or philosophy.

Have fun!
 

clolsonus

Active member
#10
If you could you should consider the starting of a survey Drone, (fixed wing), thread as there are some on the forum who are getting seriously into survey drone design and building.
In my case there are a few gaps in the market still especially in the range Vs size Vs cost. This is the area I am working in trying to widen the design criteria away from the old RC thinking and design principles to a different approach or philosophy.
Have fun!
The quad copters became super popular and took over 99.9% of the drone market and mind share ... but I think the longer endurance and greater payload capacity of fixed wings will tip the scales in the long term (at least for commercial uses.) I might be crazy, but true work drones will probably end up being sized similar to today's light sport airplanes that can cruise a couple hours @ 100+ kts with a 1000 lb payload. Compare to my Talon which can cruise maybe 1 hour at 25 kts with a 1 lb payload. But before we get there, fixed wing drones need to make a come back! :)
 

Hai-Lee

Old and Bold RC PILOT
#11
The quad copters became super popular and took over 99.9% of the drone market and mind share ... but I think the longer endurance and greater payload capacity of fixed wings will tip the scales in the long term (at least for commercial uses.) I might be crazy, but true work drones will probably end up being sized similar to today's light sport airplanes that can cruise a couple hours @ 100+ kts with a 1000 lb payload. Compare to my Talon which can cruise maybe 1 hour at 25 kts with a 1 lb payload. But before we get there, fixed wing drones need to make a come back! :)
Commercial Fixed wing drones are still lagging behind quads simply because the current designs borrow extensively from model aircraft both in design and construction but that is about to change! Payload multiplied by range is where real purpose built Fixed wing drones will come into their own!
So far using out of the box thinking manpowered fixed wing aircraft have crossed the English Channel and solar powered/electric aircraft have circumnavigated the planet. Where range is key fixed wing is king.

Sure you are correct we may soon see commercial multicopter drones the size of small cars but their efficiency will always be poor as their aerial support is all energy. Sure they are now playing with hybrids, (fixed wing and Rotary), to extend their flight envelopes but still the design thinking is a little retro!

Your mentioning of long term drone life and maintenance issues are not generally though of and any drone can be subject to an inflight failure or even incident. So as the use of drones escalates you can expect even more restrictive and punitive laws to be formulated and enforced. One additional thought is that just like the automobile when we start seeing a continuing death toll because of their operation those victims will be offered a pittance and they will just fade from view as the money drones generate will become more important than human life!

Have fun!