Wind conditions this morning were exceptionally good for a balloon launch, with the predicted landing site being only 1km from the launch point, I wouldn't even need to leave this farm property! So I woke up early and got everything ready, only to find that (as I suspected) there was not enough helium left. It was worth a try I guess. So this is what I did instead. The plane is performing very well so far. It's a real bitch to launch and land, but also tough enough to handle the consequences...
This video has been slightly smoothed, but the original was pretty good to begin with. Flying in FBWA, a comfortable 45 minutes flight on 3S 5200mAh battery, with about 1/3 of that time at 8 amps (this video :), and the rest at about 5 amps.
Mini Talon is king... may he have mercy on a pitiful wretch like me for trying to usurp his throne :)
Isn't modern technology great?
This build has now officially crossed the threshold of being more trouble than the enjoyment I get from flying it. Hope you enjoyed this series, but no doubt you're as sick of seeing one crumpled landing gear fail after another, as I am of making them. It was a learning experience though - I learned that large planes are a large pain in the ass to store, transport, assemble, launch, land, and pay for. I will not be in a hurry to make anything bigger than about 1.5m wingspan for a long long time. Should have just taken up that offer to review the 'Believer' instead of doing all this :)
I forgot to mention in the video, but that last flight with two batteries in parallel was exactly 30 minutes finishing at 14.5V under load, and all cells returned to 3.8V at rest shortly after. Dataflash log shows the current typically between 20 and 25 amps at half-throttle cruise, take-off bursts were around 90 amps.
Looks like this was already all over YouTube by the time I got home and could even look at my own footage, but for those who want to see it from yet another angle, here you go. Thanks to Neil and Ron for helping with the setup :)
Digipot setup: https://www.youtube.com/watch?v=_dUQOTemSJQ
MCP4151 JayCar listing: https://www.jaycar.co.nz/8bit-257-step-digital-pot-mcp4151-103e-p/p/ZK8879
Buttons (Banggood): https://goo.gl/KSZCHT
st-flash tool: https://github.com/texane/stlink/wiki
F407VET6 info: https://os.mbed.com/users/hudakz/code/STM32F407VET6_Hello/shortlog/
ST-LINK dongle: https://goo.gl/4N5DR1
Cheap board similar to Maple-mini, easy to use pins for flashing: https://goo.gl/jbRGGG
All pins available, not so well labelled, no onboard LED: https://goo.gl/qa6PKq