DIY Hex Aerial Cinematography Advice
Hello, I'm very new to this hobby and not well informed on electricity but I'm comfortable with electronics enough to skip past the RTF cinematography drones and build something more powerful. Thanks for any input that can be provided.
What is your budget for this multicopter build?
$3,000. Higher/lower doesn't matter, I'm opting for quality - something around the DJI Inspire or better would be preferred.
What type of multicopter would you like to build?
Hex. I've been informed I can have redundancy with more than 4 motors - correct me if I'm wrong.
What is the purpose of this multirotor build?
Aerial Cinematography using a GoPro with 3-axis gimbal - would like to allow future upgrade to SLR/mirrorless cameras.
What type of build will this be?
Scratch, I'm okay with soldering IF I know where everything goes.
What is your experience piloting RC multicopters? What about single rotor/RC planes/other RC hobbies?
Hubsan x4 flying mostly indoors, have done outdoors after gaining experience and flown without crashing. Other than that just RC cars and toy single rotors.
Do you own any parts already or have you chosen any parts that you’d like to include in this build?
I've ordered a Pixhawk since it had me convinced over other options. I considered 3DR's X8+ and the Inspire but would rather build it myself with parts I choose. I also already own the camera. I've read that the Taranis is a pretty hot deal and that T-motors are among the best in brushless motor quality. Currently considering the Tarot 680 frame but I'm also keen on using a large 6S battery to extend flight times and not sure where that fits in both dimentionally and electrically.
What country do you live in, and do you have any additional shipping/sourcing requirements?
United States, I'd like to keep the number of vendors minimum but will be willing to expand if certain parts can be found cheaper. International shipping isn't a problem, I'm not really in a hurry.
Additional comments
- I've already been running a spreadsheet on parts but need more experienced input before buying into a new hobby.
- I'm mostly worried about quality and not really worried about going slightly over budget - I would like to buy once and not need to upgrade.
- I've been doing simulations on ecalc and the only thing I find confusing is the AUW value; it usually seems like ecalc gives a heavier value than what I'm personally adding.
- I definitely want double FPV both from the copter and the gimbal cam and I'm not sure if powering the camera systems from an alternative battery onboard is a better or worse idea.
- I'm aware I'll need a second Tx to allow separate gimbal control.
Link to spreadsheet: https://drive.google.com/file/d/0BwKbWFwvYdgXODhOTjJ3d1RxUGs/view?usp=sharing
Posted Mar 1, 2016, 5:33 PM UTC · edited
You are correct about redundancy however you will need to make sure you have a flight controller which supports hex redundancy, chiefly DJI's Wookong/A2 and the Pixhawk (see this video for demonstration)
Pixhawk is a solid flight controller, I'd look at the Dropix version of it. It's tidier for wiring up as a DIY project as you can use standard servo connectors as opposed to all the fiddly molex connectors and making custom looms. Otherwise if you're not bothered by that you can get kits everywhere, banggood does a very comprehensive version with 433/915MHz telemetry, new GPS, current sensor etc. etc.
Taranis is a great deal but slightly more of a learning curve than other off the shelf transmitters. It depends if you like reading guides and googling problem solving as sometimes the Taranis can be too clever for its own good. It does work fantastically well with the Pixhawk controller to give you downlink telemetry informing you of altitude, battery voltages & current, GPS position etc. If you're not into fiddling too much and getting lost in menus I would suggest either Futaba or Spektrum.
I fly T-motors on my octocopter, they are indeed excellent motors but be careful with them, they can have a high pole count meaning you need faster ESCs to work them. For instance, my U7 kv490 motors require T-motor's own 80a 400hz ESCs otherwise they suffer with stuttering and overheating because the refresh rate on standard SimonK/BLHeli ESCs isn't quick enough to cope. Other alternatives are KDE (slightly higher price range but nigh on bullet proof performance).
The Tarot 680 frame is okay but I'm not a fan of the mainplates, personally I would like something solid carbon fibre such as the Tarot T810 which gives you scope for larger propellers meaning greater lifting capacity or efficiency depending on which matters more to you. I'm not 100% on the electronics side of the 680 but I'm not sure if you really started pushing the amperage that the mainplates for power distribution would cope. Better to get a dedicated power distribution board which is slightly above specification (most likely a 200a one would be ideal)
The bigger brother (the T960) is even more humongous, allowing up to 18" propellers but be warned once you supersize this big your budget can get swallowed up VERY quickly. It would mean you could fly anything from a GoPro to a GH4, 5D, A7s etc.
Additional comments
What gimbal are you looking to use? You mention initially that you want to fly a GoPro but it's good to keep in mind what you may potentially want to fly in the future.
edit: formatting.
Sorry to hijack this thread, but I too am looking at making an aerial rig with a Sony A7. Right now I am thinking of using:
Still trying to figure out the ESCs as am I not sure the proprietary ones are the best way to go.
I also want to get the pixhawk, but would you suggest a certain clone out there? The final goal is automated flights and 4 mile range capabilities with all the flight systems, like the FPV and the camera.
I am looking at the Movi M5 vs the InfinityMR for gimbals.
Thanks!
Nice parts for a build - I would recommend KDE's amazing folding 18x6.5" props and adapter as it makes transporting with props on ready to go a breeze.
ESCs are a tricky business, just be sure you do your research and you don't need specific ESCs for a reason (such as the high frequency example in my post) otherwise a very good quality option at the Hobbywing x-rotor and platinum series. himodel.com is a good reseller of them, very cheap prices and reasonable intl. shipping.
Really clones are exactly what they say they are - there shouldn't really be any deviation in the basic design. The main difference is usually what's bundled in the kit, as I mentioned the banggood.com deal (915MHz telemetry - not suitable for EU) is one of the better out there in terms of a bundle. Otherwise I've had good success with RCTimer.com 's clone boards, however the website is currently down so I'm not able to give you a link.
FPV over 4 miles is tough (not to mention illegal in a lot of places...) you'll likely want to go to a 2.4GHz or below frequency in order to get as robust of a signal as you'd need which leaves you less options for control - most likely something like ImmersionRC EzUHF or DragonLink etc. Because I fly in the UK our limits are a bit stricter and tbh I don't have any interest in flying my extremely expensive craft and camera kit out of my visual line of sight, regardless of how great my FPV link is.
Another option for gimbals is the Gremsy line up, although I would recommend using a DJI flight controller with that as they integrate well nowadays with the CAN-Link system they have set up to offset your gimbal pitch and roll.
Hey thanks for the reply, I've added a link to the spreadsheet. Yeah I would like to use two separate batteries but I'm not entirely sure what the wiring would look like.