"Beyond the purely mechanical problems with quads, can we talk about the Lipo, electrolytes battery problems with quads in the wider range of climates? There are arctic expeditions that we see helicopters with gas fuels routinely fairy personnel.…"

"A quad with folding props have exactly 12 moving parts(4 motors plus 8 blades), and that is also the number of moving parts for today's direct drive, fixed pitch helicopters (2 motors plus 2 servos plus swashplate plus rotor hub plus 2 blades plus 4…"

"I am trying to do the reverse. It has been 4 years since the initial discussion, and today's 200 - 250 sized helicopters use a direct drive tail and main motor is easily converted to direct drive. So, my 200 sized heli is basically a multi rotor…"

"The large propeller inertia problem can be solved if you use the swash plate of helicopter to change pitch, instead of changing rotor rpm rapidly in fractions of a second. That is why serious military copter drones that routinely have 1 hour…"

"Same goal here, with the advantage of no knowledge of 2.4Ghz transmitter. 
I did have the 80's 27Mhz transmitter and nitro engine with a big plane 20+ years ago. 
I armed my APM with a joystick button last night for the first time, bringing in…"

"You are the cool kid here. Chris Khosravi said:
I use a button on my joystick to arm."

"And the same page has another suggestion to use mission planner android. It says that the android version allows arming. Looks like it is a setting on the ground station side. The APM does not prevent arming with MavLink. John Gibson said:
I am…"

"I am interested in finding out. Someone said that long-press a safety button in pixhawk is needed, 
https://www.reddit.com/r/Multicopter/comments/2nyo32/manually_arm_a...
, but it didn't not say ardupilot ."