Long story but here it goes. Just hope that someone will pick something positives out of all this.
After weeks of sitting behind the computer trying to figure out what is needed for an FPV setup I ordered the parts. I already had a phoenix 2 meter and lost another one a few months ago due to sun-strike. I promised myself to reduce the chances of this happening ever again. And this time the wife agreed (read: open chequebook I’ll supply a list of ingredients later but there is a strong tendency for stuff which Bruce had his fingers on and also following the stunts Alishanmao pulls of at his YouTube.
The Phoenix 2000 is rather tight to put all the components in but this plane has a big wing surface area, streamlined and flaps which are effective. Relatively cheap and some part reflect this.
A few mods I did to the plane to create more space: the wooden bracket in the back which holds the rudder and elevator servos can be inverted. Check that the servo screws are tights and you need to sand a little of the bracket otherwise the two sides are a bit tight. This creates a lot of space to put a 1300mA battery and transmitter components.
The transmitter is the 5.8GHz 500mW. It has a large frontal area with the (exposed) circuit board, forced fan cooling and large heatsink with cooling fins. I disconnected the cooling fan and checked the temperature of the heatsink which took nearly five minutes to get hot to the touch. I also removed the circuit board and extended the wiring, which is fiddly but do-able if you have done some soldering before. The transmitter is at the back behind the wing secured with some cable ties, the circuit board inside and the fan stays at home. Now, the phoenix has a big disadvantage in that the wing is attached by four screws (and the servo cables). Anything mounted in this area takes a few minutes to get to. So I put a switch in to activate the transmitter just before launch and switch it off straight after landing. It works fine but it is an extra item to think of as you will see later.
The stock motor is the 2815/1050Kv (10x5 folding prop) with 30A ESC, both items I had my doubt about after problems with the smaller 1.4 meter Phoenix. Again more later. This is powered by a 2200mA 3S 20C. Further mounted inside are the FY21AP FPV Inertial Attitude Stabilizer and AP117 OSD module. All fiddly to mount in the small space available but even the vibration platform for the FY21 fits in. Make sure that the wiring does not pull the FY21 around.
BEV-KX171 is mounted on the canopy, the pan-tilt camera mount has not yet been mounted.
Despite modifications to different parts all worked fine and the Fatshark glasses showed what they suppose to show and more (optical aberrations). I had to use the full eight channels on the Turnigy 9X (with ER9X and FrSky telemetry DIY kit). As said, it takes a while to find a place for all the parts and still keep the weight and balance in check which is near perfect with this setup.
First flight:
Saturday morning and pretty nervous despite knowing that the plane can handle the load which is just under 1600grams. I had done a previous flight with just the FY21 which is such pleasure to fly and knowing the security of return to launch (RTL) in case of loosing sight.
I launched it full power and after bringing it to a good height activated the RTL and put the FatShark on. Dammit… forgot to switch the video transmitter on. Landing was uneventful despite surrounded by very high pine trees on two sides. Flaps really slow this plane down while still have good controllability.
Second attempt, now with pre-flight check and the FatShark showed what the camera shows. Off the glasses and again launched the plane. At a good height I activated the Auto Circling Mode (ACM) away from the Sun (South West). Put on the glasses and while the plane flew itself, I orientated myself with the new wonders at hand. Now, I have been flying models for some time in a previous life (and anything from hangliders to microlight and bigger) but still the joy of having accomplished something which actually works is overwhelming. 87 meters up, 55km/hr, Amps a bit high at 25A!, throttle back, about 300 meter away from launch. Volts all fine, 8 satellites, etc, etc. Enjoy the view. Colours a bit oversaturated, adjust contrast and brightness. Jiggling the FatShark to get a clearer view of the text in the corners.
So after a few minutes I noticed that the plane was down to 56 meters and still loosing altitude. Odd, because it should have stayed at fixed altitude and I didn’t notice a stalled situation. Increase power… I cannot recall what the Amps were before or after but the plane was still loosing altitude. Switch the ACM off but left the Stabilized mode on and cut the throttle. Down to just over 40 meter and well behind the 30 meter high pine trees. Options. Remove the Shark and run up the dunes past my house and shed, down the dunes to behind the pine trees (287 meters away according to GPS). No way. My first FPV has to be an FPV landing as well.
By now I am sweating in the full Sun (and my poor brains working on overdrive) and this is a second problem with the FatShark: they steam up @#$%. So I had to pull them away slightly to let fresh air flow around.
Down to 27 meters, oops the pine trees are getting close lets bank away and get into final approach. Flaps on, the Stabilizing mode corrects for the sudden nose-up. According to the ripples on the water not far away I am down wind so turn around and now heading into the wind but also increasing the distance to where I am sweating my eyeballs out.
Down to 10 meters and still reasonably good reception (receiver at four meter pole and the 500mW now came to good use). I started to see the little crab holes in the sandy mud. Glasses are getting misty and this time because of reception problems, both video and RC transmitter which start to beep at times. The plane must have been only a meter above ground when I lost video contact but still had RC control (it didn’t beep at that time). Took off the FatShark (not in the Sun, Bruce told me), raced over. Wow, all good with a long skid mark behind the plane indicating a smooth landing. Switched the video transmitter off, heatsink not warm at all. Canopy off and the strong smell of burning electronics hit me. Pulled the battery plug. Is it the ESC? The shrink wrap appears to be ok. Other electronics are also ok. Motor: cannot feel the magnets!
So, for some reason the motor had failed and had even slightly melted the plastic nose. Maybe I had too many amps on while circling and the higher weight of the aircraft? Was it the stock Chinese motor which I didn’t quite trusted before?
Now a lot of lessons learned but still an intact plane. A new motor and ESC is on its way (Hyperion). Don’t know if it is any better but the salesman insisted it was the extra $$ worth. What do you think happened and what motor/ESC would you use? There still should be enough airflow through the fuselage for cooling.
I recovered my wife’s video camera and the next flight I hope to record. Might put it on YouTube. Still a lot more to learn and next flight will be at such place I can land it visually if I need to. But the five odd minutes I had were incredible
Better get back to work to pay for all this.