I started this project as a fun hobby but at this stage its turned into a nightmare.
About 10 months ago I heard about the Wildlife Conservation UAV Challenge over the radio and decided to enter thinking that it would be a fun and interesting challenge, a chance to do some good and maybe get some money out of it but boy was I wrong!
10 months down the line, two slightly destroyed airframes(only flown twice but crashed 4 times), destroyed battery (was working fine then it lost one of the three cells after it shorted out while I was soldering on a new connector), one camera (also was working fine then just stopped working for no reason, never flown), 3 props (broken), a nearly amputated ring finger (by one of the props), lots of wiring and soldering, a FH 10 Z 10x zoom camera that doesn't zoom, blown 3v reg on the apm (fixed), Had to reinstall mission planner 3 times, I have flight gear simulator installed for HIL but it doesn't work, 4 burned out servos(replaced, HD metal gear servos are the worsted servos ever), a 2 axis Martinez brushless gimbal board(can't get it to work) and lots of my own money( R35000.00 or about $3500.00!). When I finished putting the first uav together it was a 1000grams over weight( never flew).
Got the second airframe, set it up and it weighed 1600grams( perfect) but it only hand launches in heavy winds and in no wind condition( perfect flying conditions), it has the glide path of a brick.
Now I must probably mention that prior to this project I had no experience with regard to radio controlled aircraft, UAV's and I have never flown a rc plane before in my entire life. I do have a basic understanding of electronics and soldering as well as antennas and radio theory.
It seems to me that this hole project is doomed to fail( nothing want to work). But I wont give up this easily. Most if not all of the information that I needed I found on DIY Drones and before that I was to proud to ask for help but I am now desperate for help and if anybody can point out my mistakes and help me get my UAV project of the ground I would be very grateful.
I ran out of space here so if anybody needs info of my setup please ask.
Replies
Ok, here's my setup.
The first airframe was a FPV Raptor. I picked it because of the massive space inside(that turned out to be completely impractical for my purpose. Too many curves and the fact that the body narrows towards the rear) and the lack of options I had on airframes at the time( South Africa, go figure).
The electronics side I have the APM 2.6 with a 433mhz 3dr telemetry radio and ublox gps.
My radio is a Turnigy 9xr with a RMILEC 433 MHz UHF TX and RX module.(I checked, there is no interference between the telemetry radio and the RMILEC.)
Video is a 800mW( I had a lawmate 1W but it got fried because of the wrong antenna. I now know what the difference is between SMA and RP SMA) 1.2ghz transmitter with a clover leaf antenna and the receiver has a 10 dBi patch antenna.
The Camera that I want to use is a FH 10Z 10x zoom camera but I have yet to get the zoom to work. OSD is a minimosd.(its a pretty tough little piece of electronics, connect the 12v wrong and you see smoke coming out of it but it just keeps on ticking)
I replaced the stock ESC and motor of the raptor with a HK 30A ESC(the blue Ubec kind) and the motor is a Turnigy 2836 750 KV
with a 8x8 prop.
Ground station is mission planner.
Flight batteries are 2x zippy compact 4s 5000mAh batteries in parallel.
The original specs for the UAV is that it is supposed to stay in the air for up to an hour and have a range of 10 km, be hand launched and easily repaired in the field. There should be a minimum amount of ground support equipment eg. ground station and plane all should fit in a backpack.
In order to get the endurance sorted I was introduced to a neat website called ECALC. Figuring out the best motor, battery and prop combo for the uav to achieve a 60 min flight time seemed easy enough and I did get the right info hence the new motor, 8x8 prop(that clearly showed that it WILL stall with that motor but in my ignorance I used it anyway) and 2x 5000mAh batteries(which is also the reason I blew my weight by a KILOGRAM!) I could get an amazing 73 min flight time(want to take a guess why it never would have even took off let alone fly?)
After I figured out why the raptor could not fly( and crashing it every time trying to launch it) I figured that I need a different airframe, something smaller and lighter, that's easy to take apart and transport and should do the same job with only 1 battery.( I was completely sober when I made that decision) I came across the X UAV Mini Talon( again lack of options)which turned out to be a much better airframe and a pleasure to work on. It can take 2 of the 4s 5A batteries and all up only weighed a smidge over 2kg(on the website it says it can fly with 1500-2000g) but with what motor and prop? On the box it says it comes with a 2836 1300KV motor, make?(fong kong) but when I got this Talon the shop owner had already assembled it and was hanging from the shop ceiling and it had a different motor, 850KV, make? (no name brand). It had a 9x4.5 prop.
So I decided from past failures not to try and fly it with 2 batteries and rather go for 1. Weight was exactly 1666 grams(the first sign that this thing is cursed).
So I spend the next week fixing things that seemed to work fine the one moment and just when you think your ready to take to the air something else breaks(for no reason?)
I eventually got everything working (at the same time) and decided to take her out for her maiden, then mother nature intervened with the heaviest wind of the week(common sense should have kicked in at that time but I decided to go b&*#s out and go for it anyway).
Now I have to launch the Talon myself as I don't trust anyone else to do it for fear that they might get it wrong and throw it into the ground. I have to throw it with my left arm, open the throttle with my mouth and control the elevator(and only the elevator) with my right thumb and get it right the first time without chopping my arm off in the process. I'm right handed, I throw right handed, I write right handed now I have to throw a 1.6kg piece of foam into heavy, gusty wind with my left hand( and yes I do throw like a girl with my left hand) and control the whole thing with just my right thumb. Well it flew for maybe 2 min when I figured the CG is so far forward(after I made sure that the plane balances perfectly on the CG markings on the wings) that when I switch to stabilize or FBWA its not even trying to level it out. Long story short, I brought it in for a landing and right before touch down everything went south from there and I had to pick up the talon, both pieces.
What am I doing wrong?
Flying UAVs now is comparable to having driven a car 100 years ago, and there would have been lots of stories about breakdowns, fires and long walks home in the night...
"Flying UAVs now is comparable to having driven a car 100 years ago, and there would have been lots of stories about breakdowns, fires and long walks home in the night..."
That's what makes this such an exciting project because how many people do you know that can say I have build or flown a uav.
Sorry to hear your tales of woe Marcell. Perhaps the thing to do is start with a Bixler, learn to fly that and move on from up from that. Small steps.
Sounds like the Talon is only in two pieces so glue will work! I have the bigger Talon with wing extensions and I love it. I do get nervous flying above 2.6kg AUW remembering that I live at 5000' and it can be hot. Figures for weight and endurance that are around are normally for folks flying at sea level or nearby and in sub 30C temps it makes a heck of a difference if you are hot and high.
Keep going thought it will come right in the end.
If you can find Talons at the minute you had better snap them up, the factory is closed whilst moving and not sending any more out for a while.
Thanks for the reply. I did superglue it together and it still looks like new. I love epo foam. Just hope it holds together, although I did think about fiberglassing the out side of the talon for extra strength, I'm also at 4500' so other people's maths do no necessarily apply to everybody.