"@VGR, thanks for the info. I didn't know there is such motor available. I always wanted to build a coaxial rotor and this maybe the way I want."

"@VGR, I've watched all the videos in your website and they're very cool.
What I mean is the coaxial coupling, which are the components number 106 and 108 shown here: http://vgrsystems.free.fr/?page_id=130
Do you have one motor with hollow shaft so…"

"This looks very nice! Do you mind sharing the coaxial counter rotating mechanism showing how it works with your motors?"

"We call this compliant mechanism in the university. It has a lot of possibilities but sometimes it's tricky to have a good design.
I think is quite feasible to have such mechanism for our rotor system, we just need some nice design for it. Looking…"

"Just found this: http://www.auvidea.com/index.php/theme-styles/2014-12-30-22-32-06/b101
I'll buy one in May and connect it to GoPro. Let's see how well it will perform."

"I was thinking about the GoPro bus that 3DR was talking about with the release of Solo, however there is no info available at the moment and I doubt it will never become public. The HDMI output comes out from Gopro has some noticable latency, so I…"

"I got it working, but the solution is quite strange. I tried to change the config-interval=5 as mentioned above and reboot the Pi. Now it works perfectly, even if I change back to config-interval=1. I have no idea why it's like this, but now I can…"

"I'm trying to stream the video from pi but it stucks with: "New clock: GstSystemClock"
I'm using this command: raspivid -t 0 -w 1280 -h 720 -fps 40 -vf -b 2000000 -vf -hf -o - | gst-launch-1.0 -v fdsrc ! h264parse ! rtph264pay config-interval=1 !…"

"The SBC QS600 looks nice, is there anyway we can order it in EU?"

"awesome. one difficulty of small uav in this case I can imagine is the relatively small space to fit the equipments between these two motors, and how to put the antenna vertically."

"@Patrick, yea exactly. I've just ordered one and will see how it performs. Btw I think the Pi doesn't have enough power for this dongle, so probably external power is needed. The dongle has a power input socket but they didn't mention the voltage,…"

"@Patrick, 110ms is pretty nice. I found a wifi dongle on ebay which claims 3km outdoor range, which blows my mind... I'm not sure whether it's real, I guess I'll buy one and have a try. I don't know whether I can put the ebay link here, but you'll…"

"@Dom & Patrick, thanks for the info. I'll order one and see how it will perform.

I'm thinking of using a USB wifi dongle just for open area short range (20m max.), maybe with an amplifier for longer distance if needed. I saw some blogs with that,…"