Have been building up a basic octocopter (already have other quads) based on cost looking to eventually go to a nice frame.

Whilst the Hobby King frame is nasty and cheap it is a start and for under $40 it seems OK (yes it has its problems)

My intention is to figure out best prop motor configuration for longer flights, etc.

Hobby King Octocopter frame - landing gear is woeful!!!

Turnigy 35-36 910kV propdrive motors with prop drive adaptors

12x4.5 props - at present

30 Amp Turnigy plush ESCs (wiring needs tidying)

2 x 3300 Turnigy 4S batteries in parallel

HK antivibration foam (orange) under a range video mount with APM 2.5 on top

Waiting for external compass and to mount GPS at present

Turnigy 9XR radio, FRSky module and receiver

3DR radio link


Intention is to put my brushless gimbal with Sony NEX5 on it for some video just for fun.

Have not done a compassmot or compass calibration to date but did actually fire her up and see what happens.

Jumps in the air alot more aggressively than the quad and the noise is a bit frightening, response to throttle was a bit more sensitive than expected. Was really stable in windy conditions during initial tests. Remarkably more stable than smaller quads I am used to.

Have not looked at tuning so far as only preliminary tests on stabilise.

Anyone looking to do the same thing happy to share experience or any advice or considerations are welcome.

Cheers 

Brian