Building my first Tricopter - Advice and tips appreciated! Current list of items

[hinto]

Hello!

I am looking forward building my first tricopter that i can be proud of!
Any advice and tips are welcome! I am pretty new to this kind of stuff but I'm willing to learn and hopefully make quality work!

Still looking around and trying to find right parts for my build, so I'm turning here for the recommendations, maybe we can make some changes to get best possible results.

What I'm looking from the build

Current build I'd like to focus on maximizing flight time and stable flight. For taking pictures, making videos from the sky as long as possible.

Here's the list of the current build:

The frame

I really liked David's design of the tricopter.
So I'm going with RCExplorer frame made from 1.5mm thick fiberglass.

Also adding Camera/battery tray kit for storing battery and camera.

For the motor tilt - Tricopter Tilt Mechanism

3x booms
The 3x booms would be from 12mm poplar square dowel(wooden). Back side that has Tilt mechanism would use 37cm boom and 2 x front side would be 35cm.
I heard that such set-up gives more stability, that's not too long nor too short.
I could test different lengths, maybe someone got any tips here, about lengths.

Electronics & other

LittleBee 30A ESC - that is pre-flashed with BLHeli 14.3 firmware. Adding Turnigy USB Linker, for flashing possibility, if needed.

Motors NTM Prop Drive Series 28-30S 900kv / 270w -
Maybe you guys got better recommendations for the motors.

Propellers - Still can't decide.
For that above motor(28-30s 900kv) there are recommended prop sizes:
13x4E - 11.1v - 194W - 17.4A - 1.04kg thrust
12x6E - 11.1v - 195W - 17.8A - 1.01kg thrust
11x7E - 11.1v - 188W - 17.0A - 0.89kg thrust
10x5E - 11.1v - 133W - 12.0A - 0.75kg thrust
9x6E - 11.1v - 120W - 10.7A - 0.68kg thrust

I'm thinking something between these values, as i read that bigger props with little less motor rpm per volt(kv) decreases some of the load as allows more thrust.
Still pretty confused about this, so I'm seeking for some advice and tips before making final decision.

The servo - Turnigy™ TGY-210DMH fits well with above provided tilt mechanism too.

The Battery - Turnigy 3000mAh 4S 20C Lipo Pack.
Not sure about this 3000mAh capacity. If i want to increased flight time, maybe i should go with 5000mAh or something? How much it matters with such set-up?

The Flight Control Board - HobbyKing™ KK-Mini Multi-Rotor Flight Control Board,
chose this as feels like it gives me nice interface with plenty control and easy access over the controller.

Transmitter and Receiver - Turnigy 9X 9Ch.
I'm not sure how to calculate the distance, how far this build could fly with this Transmitter and Receiver, which is also important.

These are the main parts that i brought out, what do you guys think?
Would you have any fixes for the list? To increase performance for the build.

Any advice and recommendations are welcome!

Thanks!

 

[TestMaster]

For the props, it all depends on how fast you are looking to go, if you are going to place an FPV... As a first tricopter, I would recommend a 11x7E because it's the most balanced and it should give you a good overall performance on a 900kv motor. But it all depends on the flight characteristics you are looking for. For the batteries, I would stick with the lighter one, just because it will give you a better flying quality, but you may want to buy a couple so you can fly longer.

 

[hinto]

For the props, it all depends on how fast you are looking to go, if you are going to place an FPV... As a first tricopter, I would recommend a 11x7E because it's the most balanced and it should give you a good overall performance on a 900kv motor. But it all depends on the flight characteristics you are looking for. For the batteries, I would stick with the lighter one, just because it will give you a better flying quality, but you may want to buy a couple so you can fly longer.

Thank you for the reply and tips.
I'm looking more for a calm flying and trying to get as energy efficient as possible.
I gonna consider that 11x7E size, thanks.

Also, what do you guys think about motor and current ESC's? I guess 20A ESC would be enough for me, i could change that instead 30A one, as motor max current is 18A anyway.

Got any other motors and ESC suggestions?

 

[Craftydan]

A few points on the list above . . .

- The Littlebees are great ESCs but they're OPTO, meaning they won't provide power to the servo or control electronics. You'll need to add on a external BEC (Battery Eliminator Circuit, AKA, a voltage regulator) or a PDB (Power Distribution Board) with voltage regulation built in. Positive side of a PDB is they can dramatically simplify the wiring harness.

- kk2 mini . . . well . . . if you must. These boards are nice in the fact that they can easily be configured while on the field -- I've been able to completely factory reset and setup a board in the field in a few minutes and was tuned within a pack or two. That being said, the stock ROM is garbage, so IMO it must be reflashed, and not to the "latest Software version" from hobby king . . . because Hobby knig doesn't know how to write software To flash it you will need to pick up a USBASP adaptor (hobbyking's will work but they can be found elsewhere), download the KKmulticopter Flash Tool from Lazy zero, and flash the latest Steveis or RC911 ROM. Or you can go with a better board. The Naze32 boards and their myriad of clones (search for cleanflight) are good boards and fairly popular, as are the OP boards (I'd avoid the CC3D's . . . never been happy with one), but any of those will require a computer/smart phone to configure them, preferably one on the field. Computer needs only a USB cable. The Smartphone will need either a Bluetooth adaptor for the board or a USB-OTG cable (if the phone supports USB-OTG)

- NTMs . . . just . . . no. Cheap bearings. fine for fixed wing, but you'll start fighting vibration issues from failing bearings just about the time that starts getting important to you. I've been pleased in past with the larger SunnySky motors (their tiny ones for 250 and smaller quads like to throw magnets, but the bigger ones are fine).

- Props . . . size to the motor you pick . . . or pick the motor speed and power to the size of your prop, but it's easier the other way around Longer props fly more efficiently, but cost WAY more, and are MUCH easier to break. Stiffer props fly better (Carbon vs. carbon/nylon mix vs. Nylon), but cost more and break easier.

- Props . . . you will break MANY props. Get over that fear now. BUY MANY. Not much worse than not being able to fly because you're waiting for the mailman to bring you a new shipment of props. I typically recommend buying 5 complete sets to start . . . and consider buying more. If you buy something idiot-proof-stable like a DJI phantom you can get away with only having one spare set, but that's nothing like what you're spec'ing out here.

- Props (once more) . . . The second number on the prop spec is the pitch -- how far forward the prop must travel with each revolution to work at peak efficiency. How far "forward" is the prop moving in a hover? That's right, not at all. To get the most out of a multirotor, the goal is to go high on length as you can afford, but with a shallow pitch. That 11x7 may be better matched to that NTM motor for power consumption, but you'd be better off with a 12x4-ish prop. For that matter a 13x4 will draw about as much power at WOT (wide open throttle) as the 11x7, but hover VERY efficiently, but a set of these won't be cheap.

 

[hinto]

I'm so thankful for this information!
I gonna keep looking and researching different motors, hard to choose, so many brands and stuff ^^.
For Flight control board, i gonna stay with this kk2.1.5 as my first board and try to flash it with Steveis, or RC911 ROM, would be great experiment.

Also, do you have any GPS system recommendations? Something to locate drone position, speed, altitude. Maybe even such system that has auto-pilot feature, that returns your drone to home when there's signal loss or some other issues, is that possible or would it be way too complex?

Thanks again!

 

[Craftydan]

By all means, if you want to tinker, the kk2 series boards will allow you to do just that.

GPS, however, it will not. There was a gentleman that hacked the flight controller to support some very basic GPS functionality, but he did so by completely replacing the existing ROM. The screen and button interface wasn't written in, so the good user interface was completely gone, removing the kk2's strongest selling point. Impressive, but it was more of a proof that it could be done, not something that was done well.

It's also not well suited to AP airframes, but IMO, the Tri isn't a great selection for a hovering AP frame. It's strong suit is it's wide sweeping flight characteristics make it great for the fly-like-a-bird video, with the ability to stop, but once it's stopped does it make a great flying tripod? Not so much.

As for "autopilot" . . . It's appealing to the novice to have the "RTH" safety net, but from those who've played with it . . . Don't trust it.

Treat it like the treacherous slave that it is. It's comforting to believe that if I loose orientation or video I can flip a switch and it will automatically turn around and fly back to the launch point, but it's just that and no more -- a belief. Too many things can go wrong (more so, in DIY), and any one failing and your airframe can begin it's own journey of self discovery . . . all the way to the crash site. Where will that be? Over a crowd? Neighbor's house? Busy road? Deep in a dense forest? The local petting zoo full of children and puppies? It is courting trouble. It's one thing to be able to manually fly or let the GPS hold a spot in sky for you, because you can pick that spot and keep it clear of things/people on the ground -- you still retain some control. once an autopilot takes over because you've lost control, you are now at the mercy of your slave. As expensive as it can be (which is why I hesitate to fly expensive things), I find it better to limit my damage by plummeting to the ground when I loose control, because I can pick what I fly so I can pick where it might crash.

Proceed with due caution.

 

[hinto]

A few points on the list above . . .
- The Littlebees are great ESCs but they're OPTO, meaning they won't provide power to the servo or control electronics. You'll need to add on a external BEC (Battery Eliminator Circuit, AKA, a voltage regulator) or a PDB (Power Distribution Board) with voltage regulation built in. Positive side of a PDB is they can dramatically simplify the wiring harness.

I can use XT60 to 6 X 3.5mm bullet Multistar ESC Power Breakout Cable to power ESC's i guess or it's still better to use PDB? Currently most of the ESC's that I've been looking for the multirotor build seems to be without BEC

Also can you tell me, how is Naze32 from KK2 board energy efficiency wise? Any difference? As it states as racing flight controller, I'm not looking to race, or it doesn't even matter?

Something has started driving me towards Naze32 after doing some research.


Thanks for the advice!

 

[Craftydan]

I can use XT60 to 6 X 3.5mm bullet Multistar ESC Power Breakout Cable to power ESC's i guess or it's still better to use PDB?

Better is a matter of personal taste. Selecting a simple PDB won't be much different than the power-loom you've linked, but a more advanced PDB can help integrate more functions into the that board, like the BEC, LC-filtering and OSD. Price goes up as features are added, but a PDB with the UBEC built can be fairly inexpensive.

Currently most of the ESC's that I've been looking for the multirotor build seems to be without BEC

Yup, that's the current trend. No sense in mounting 3-4 ESCs on the airframe with UBECs when you only need one . . . and most builders prefer matched sets of ESCs. That means the 1 non-opto + 3 opto sets are generally less popular than the 4 opto + BEC. Right now Racing/Freestyle is driving most of the innovation, which lends to smaller power systems, but while moving the BEC off the ESCs isn't a huge benefit to AP platforms, it doesn't hurt either.

Also can you tell me, how is Naze32 from KK2 board energy efficiency wise? Any difference?

Your flight controller and radio draw SO MUCH LESS power than the motors keeping you aloft, their power consumption is effectively negligible. I wouldn't worry about that.

As it states as racing flight controller, I'm not looking to race, or it doesn't even matter?

Perhaps. The Baseflight/Cleanflight/Betaflight ROM's features are tailored to racing, but these boards are quite capable of basic stabilization. Tiny 100mm Race platform or monstrous 600mm AP, this board will be able to hold the airframe in the commanded attitude and move as commanded. It's not great at GPS features, but that may change in the next few versions -- a fork of cleanflight is developing better GPS navigation, but it hasn't been folded back into the trunk.

Something has started driving me towards Naze32 after doing some research.

As I've mentioned, it's a good board and on the inexpensive side. The inexpensive alternatives ATM to the Cleanflight capable boards are the Open Pilot capable boards (there are a few boards that can do both OP and Cleanflight, but few can do it cleanly). These include the CC3D, Sparky, Revo, Brain . . . and probably a few more. Other than the previous caveat of "I've never been happy with a CC3D", these are fine boards, with the more powerful versions having a good GPS hold functionality. The Open Pilot ROM itself is somewhat defunct -- the "owners" of it decided to close the source -- but a few forks, like Libre pilot, Tau Labs and dRonin have emerged.

Next higher in the food chain is the Eagle Tree Vector, which can run a tricopter with GPS stabilization very well, but isn't cheap. In performance it's bested by the DJI Naza series, but DJI doesn't support tricopters.

 

[Montiey]

I just built and flew a 500mm T-Copter with the Naze, Tough Tilt, and some 3D printed components. Flies great, but also should be able to handle some features down the road.