If it’s not the best place to start this thread, sorry in advance…
My goal is to build a drone that can carry a camera and a simple gimbal for photography.
I have already built a 5inch drone to gain experience in drone building, configuring, flying (crashing ) - but that drone was destined to be underpowered and it is indeed underpowered.
Now it’s time to start building the final drone. Below setup is based on eCalc.ch:
Flight time: about 30minutes
Maximum TOW: about 4000g with 6s4p pack
Thrust-to-weight ratio: 3.5
Frame: H680 foldable carbon frame
Battery: 6s4p EVE 40PL (maybe 6s3p)
FC: MicoAir743
ESC: 4-in-1, 60A minimum
Motors: Emax ECO2 3115 500kv (eCalc.ch estimates 85C motor temp at full throttle, but I think it’s not an issue)
Propellers: 15x5inch, bi-blade, foldable
Gimbal control with simple servo
Current sensor: Mateksys I2C-INA-BM (max battery current is expected to be 191A, this sensor board can handle it)
GPS
Later I may add optical flow sensor and down-facing LiDAR for better position holding capability (after testing on a smaller drone)
VTX: analog or digital, not decided yet
Before spending a ton-of money, I would like to ask the experts’ opinion about this setup.
Is there significant improvement opportunity in the “design”?
Are there huge mistakes in the setup?
Where can I expect difficulties during assembly and tuning?
by this you mean a gimbal using servo as its motors?
if yes, I won’t recommend it if you are doing some videography work (you have mentioned photography but servo gimbal isn’t great for anything other than pointing in a general direction.
I would recommend you to buy a brushless gimbal (3axis preferably, 2 axis also works). Even cheap boards like Storm32 work fine, and they are supported by ardupilot.
If you still decide to use servo gimbal, you should go with motors based on payload; for light payload like analog cam, sg90 or mg90s are sufficent, but for a proper camera use mg995 atleast, preferably digital SBUS servos as they are far better quality and faster response (but check datasheet once).
Trust to weight ratio of 3.5 is very high, you’d need to have a payload fitted at all times.
You can easily reduce this by using smaller props for the times when you dont have a significant payload. Just put the bigger props on for tough jobs.
With any frame there will always be a certain amount of modification required, so be prepared for that.
Innloi have something similar and I’ve purchased frames from there before. I’ve found their carbon fibre is good quality and the frames go together well and are nice and stiff. Choose an option with the 2.0mm thick CF
@Ishitbh
Videography is not in my plans. I’m more like a photo-guy. On the other hand, videography would need a 3axis gimbal - that’s way more heavier.
Now I’m using a 20kg servo.
In the future I may switch to Storm32, I already have a board at home - I know it’s far better, sophisticated.
@xfacta I’m prepared for drilling, curring, soldering stuff. That’s the fun part
I already tried to “limit” thrust-to-weight ratio to a more considerate value, to limit the peak battery current. Both to be able to measure with Mateksys sensor both for keeping my connectors small.
I can decrease even more, if needed - be reducing either prop pich either motor KV (400KV is a lower from EMAX ECO2 3115 series)
I’m planning to use a similar frame what you shown:
I would recommend lowering the prop size, if possible.
it allows you to increase thrust for cheaper in the future, when you would add other things like 3axis gimbal etc.
changing props is far easier than putting new motors, go with the current ones unless you plan to add more stuff (like gimbals, telem, action cams, etc)
Interested to know why this may be an issue? I’ve had copters with a T:W ratio of 4-5 before and where I only fly them in LOITER, AUTO or GUIDED (no FPV or ACRO stuff) and they were completely fine. It was nice because I had weight budget for a payload if I wanted one attached.
) - but that drone was destined to be underpowered and it is indeed underpowered.