Hey guys,
First post here, but I'm a longtime DIYer (hovercrafts, stereos, LCD projector, gokarts, vintage cars with big engines in them, CNC machines etc etc). I'm a 27 year-old mechanical engineer, and a little rusty on electronics, but I get by.
I've been commissioned to build an octocopter for a friend of mine, and I've got two questions:
#1, do you see any foreseeable issues with the setup listed below?* is there anything that I'm missing?
#2, I want to run a gimbal for a Canon 7D; what do you recommend for controllers/rigs? a two axis, auto level, would be sufficent - with an ability to gently change the pitch on command from the ground. the yaw will be controlled by the aircraft rotating. the roll is useless, and should be completely auto-levelled. I could build the rig and rewind the motors myself, but I'd rather spend my time elsewhere.
*Here is the planned setup:
Multiwii controller:
http://hobbyking.com/hobbyking/store/__31138__Multiwii_and_Megapirate_AIO_Flight_Controller_w_FTDI_ATmega_2560_V2_0.html
eight motors:
http://hobbyking.com/hobbyking/store/__26963__Turnigy_Multistar_4225_390Kv_16Pole_Multi_Rotor_Outrunner.html
eight controllers:
http://hobbyking.com/hobbyking/store/__25366__Turnigy_Multistar_45_Amp_Multi_rotor_Brushless_ESC_2_6S.html
right hand props:
http://hobbyking.com/hobbyking/store/__28289__Slow_Fly_Electric_Prop_1447_2_pc_Grey_Right_Hand_Rotation.html
left props:
http://hobbyking.com/hobbyking/store/__28288__Slow_Fly_Electric_Prop_1447_2_pc_Grey_.html
TWO 8000 6s batteries on board:
http://hobbyking.com/hobbyking/store/__18210__Turnigy_nano_tech_8000mAh_6S_25_50C_Lipo_Pack.html
power supply to go with the charger:
http://hobbyking.com/hobbyking/store/__20611__Turnigy_1080W_100_120V_Power_Supply_13_8V_18V_60amp_.html
I punched this info into http://www.ecalc.ch and came up with some pretty good flight times (15-30 mins) with 2kg of payload. I'll be using his transmitter/receiver taken from a Blade 450
thanks,
Sim
Replies
"I've been commissioned to build an octocopter for a friend of mine, and I've got two questions:"
I don't have any specific answers to your questions, but, does your friend have any experience flying multirotor aircraft? Will a total-loss crash be the end of the friendship? In my limited exposure to multirotor aircraft, when learning to fly, you will crash.
At least use a dummy camera weight while doing your tuning and test flights.
I'm building an octo with same motors also for a canon 5d mk2. I've not flied yet but i've almost finished.
I plan to use wood props 13x4.5 gemfan, more stable I think. 2 x 6000mah 5s batteries.
My frame is 100% DIY, 13mm alum square tubes and CF plates., about 980mm diam.
That's a great goal project, but I'd recommend getting into it more slowly.
If I were you I'd be trying to build your own smaller, cheaper quad first before launching into the big guy. If you get one thing wrong you'll have a crash or a flyaway, better to learn those lessons on something less expensive+dangerous.
the frame will be made of extruded square tube aluminum, and it will have an onboard parachute as well.