First Tricopter Build - Advice welcome!


Hello guys,

This post has gotten a bit long... Skip the first part (marked #) if you dont have much time for my life-story:
I'm looking at this hobby for 1-2 years now and really want to get into flying multirotors. I had a coax-heli a few years ago, but it was broken from the beginning on and the shop I bought at was bankrupt when I wanted my money back...

But now I want to try again! And this time, I wanna be building one on my own. I've watched every single video (not really, but I've seen too many hours) on youtube about multirotors and KK2 boards and FliteTest and so on and so forth. I'm really excited, that you can fix most things for a few bucks if something doesn't go to plan (unlike the coax I bought, 140€ trash)

I came here to get some advice of people knowing much more about things as I do. Here's my part list + some annotations for my Tricopter build (inspired by RCExplorers Tricopter V3). I had to change a few things from David's list, because I want to order them from HobbyKing Europe, and many things aren't available. Maybe you guys could have a look at it, so I don't buy useless or wrong stuff or I am missing something important. As I have to ship nearly all things I want to have, I don't want to be waiting weeks and weeks for that one single part I forgot.

1x Spektrum Dx6i + 1x AR610 Reciever - Do the recievers probably break and ordering a second one from the get go would be a good idea? Do you think 6 channels are enough for the mid-term? HobbyKing do not sell these, but I saw them on ebay for around 100€ (reciever included).

5x NTM Prop Drive Series 2830-1100KV Motor + mounting accessory - I really need advice here. I didn't find any of the propsed motors at HobbyKing EUROPE (they should be ready to ship, as I have heard that it takes weeks to backorder...). Is buying 5 of them enough, or too many to start with?

5x Afro Slim 20Amp (SimonK Firmware) - Heard the afros are good. Are 20 Amp enough? The normal 20Amp afros with BEC are out of stock now. How do I power my KK2 and reciever without BECs?

3 x 4S 3000mAh Zippy 20C - Are 3 enough, too many or do I need more of them to have fun?

1x battery charger - I really have no idea what to buy. Can u name a good one (available at HK Europe, not too expensive)

2x Turnigy Digital high torque bearing servo 15.8g/3.9kg/0.13sec - The closest servo to the ones proposed by RCExplorer that I could find available at HK. Is this okay? Are 2 enough?

4x set (3 pieces) 8x5 Props - I have no idea wich props to use, I know I should use plastic ones, not carbon. Can u show me props that I can use (they have to be CW & CCW,right?)? Is 4 sets enough for the beginning? Or should I more like buy 8 sets or so?

1x KK2.1.5 - Should be good for beginners. I like being able to configure it on the field.

10x pair of bullet connectors 3.5mm - 10 should be enough, right?

10x 60cm and 10x 10cm servo leads - HobbyKing is out of stock on all servo leads. I will get them off of ebay or something.

18 AWG cable - Have that laying around.

Soldering iron, solder, hot glue, wood glue i have laying around.

I want to build a simple Tricopter frame out of wood, glue and zip-ties, as long as you don't strongly recommend not to do so.

Is there something I'm missing? Do you disagree with anything I want to buy? I'm really thankful for any tip you can give me on my way to my first self-made Tricopter!

Sorry for this wall of text. Thank you in advance for your reply!
- Nils (aka 1387)


Hello guys!
I finished my Build and been flying for about a month now. Everything went far better than expected and I learn fast. I want to keep my promise to document my build here, so if you are interested, please read:

I layed out the components on the table. I later bought the stuff for the frame (thin wood, aluminium tubes and screws) from a hardware store. As David Windestal doesn't really recommend aluminium i was sceptical at first, but I liked the idea to hide the cables and my Afro Thin ESCs in the tubes nicely protected. My father said the arms should hold up pretty well and he was right! I had no copter -> wall high speed accidents but some major crashes and I only had to replace 1 arm so far when my father maneuvered the copter into a very high tree and it fell down 15m. :D

The first thing I did was to flash the KK2 board.
I think many people fear this step, because if something doesn't go to plan, there is a small chance to brick the microcontroller. But as I had some experience (hence the STK500 board) with Microcontrollers I figured I could save the money and not buy a USB Programmer and flash it via the programmer on the STK500.
For all you who just getting started: Don't worry if you don't know what I'm talking about. You just need a device to conect the KK2 to your computer and install the latest software. You just need to buy a so called AVR ISP (In system programmer) with 6 Pins. With the Software KKMulticopter Flashtool, you can't really do something wrong. You just select your connection type in the list (e.g. USB or the COM Port), then select the board that you got (e.g. KK2.1.5) and click "flash" or something and a few seconds and a few blinking LEDs later, your done! Remember to plug your ISP into your computer before starting the tool, because otherwise your connection may not appear in the list (my USB->COM Adapter had to be plugged in first, otherwise the COM Port didn't appear in the list).

I put together a testing circuit very quick and dirty to test if everything worked as I expected. It was a tiny bit harder for me, because the Afro Thin ESCs don't have a battery elimination circuit. This means that the don't give power to the KK2 and from the KK2 to the reciever for your RC link. So I had to use an external BEC (the black thingy on the bottom of the picture). I tested if it is possible to plug the ESC in the DATA/BND port on my Reciever, because if I wanted to use all 6 channels of the reciever, there wouldn't be a port free to power KK2 and reciever otherwise. But the DATA/BND port works for power supply. It really would not have been a problem if it didn't, it just had required me to solder a Y-connector that I can put power into e.g. the throttle Servo Cable between KK2 and reciever.
A quick information for all you Tricopter builder:
You need to get 5V to the KK2, the reciever and your servo. On the reciever, every 5V and ground pin is connected to one another, so it doesn't matter to wich pin you put the power. On the KK2 on the other hand, the power+ground input pins are connected to one another. The input pins (on the left) can provide power to the KK2 aswell. The M1 output port on the top right is conected to that aswell. So if you have a ESC with BEC connected to your M1 port, it will power the KK2 and from there your reciever. Power+ground from M2-M8 on the other hand are not connected to M1 or the KK2. So you can't power the KK2 from there. This is, so you can split the power circuit for the KK2 + reciever from the power circuit for servos. What that means for you is, that you need to provide power to one of the M2-M8 ports for your servo to work. I just made a Y-harness for my UBEC and connect that to the BIND/DATA Port on my reciever to power reciever + KK2 and the second plug goes into the M8 port on the KK2 to power my servo.

This is my tilt mechanism. Nothing really to say about it. You can get further details and where to buy the white joint thing on This is a 1:1 copy from his earlier copter designs (V1 - V2.5HV i think, haven't checked though).

This is a very cheap prop balancer. The screw thing is off HobbyKing for a buck or so. The black things are from a LEGO-like set (it's called fischertechnik, don't know how popular that is outside of germany). It is very cheap but suits my needs I think. A had very much luck with my copter/camera setup. I don't really have jello in my image even without balanced props. I know you should balance your props and motors, but as I can't seem to see a difference, I have to say that I don't really balance them anymore. I just chuck a new one on after I crash.

I really forgot to take pictures half way through. This is the first Version of my finished Tricopter. It flew very well without touching the KK2 Gains one bit. The wiring is a heavy mess and I cleaned that off and cut it shorter after I maidened it. I firstly wanted to make sure that everything worked before I cut cables. Since then I rebuild my copter 3 times, I will show you later on.
The ESCs are so small that they can fit inside the arms. I think it is very nice as aluminium should transport the heat away very well and they are nicely protected. With this setup, I didn't had to extend the servo wires or power wires from the ESCs, all I had to do was solder a 20cm 3 pole extension cable 2mm bullets -> 3mm bullets to connect the ESC (2mm bullet) to the motor (3 mm bullet). It is a very easy and clean setup. It has a few bullet connections wich could have been soldered instead of plugged, but I like that I can swap out motors without a hassle. I can just plug a new one in. At first I plugged the ESCs into a Y-harness aswell. But the Y-harness was too long and it was a mess all around. So now I have soldered all the ESCs together and used only 1 pair of bullets for all of them. This is much cleaner as you will see on the last few pictures.

As I said: the wiring is a mess. It is definately cleaner now. My servo extension cables came 3 weeks after this foto. So I had to make my own using the three blue cables u see on the left. It worked luckily, though it was very risky. The thing would have crashed if I couldnt move the tail servo... I have extension cables now and put the cable for the back servo thorugh the booms aswell.

These are my landing gears. Using really big zip-ties as a landing gear has proven a very good idea for me. It doesn't look as nice as other landing gears, but they are a little bit springy that they absorb a lot of the impact when crashing right side up. They are cheap, easy to replace and you can decide wether you want a really big loop and high ground clearance or a smaller loop, a little more stiffness and less ground clearance. I like them.
The motor mount is an old version. I now screw my motors directly to the arms. It is far more stable, less weight and cleaner all in all.

Version 2: I swapped the wooden frame plates with aluminium ones, as the wooden ones suffered too hard from the pressure of the screws. It was the wrong wood.
The aluminium plates look far better, are more stable and are only a little bit harder to cut and drill. The design of the plates is from David Windestals site You can get the plan for free there or spend the money for a complete frame out of carbon. The carbon frame is maybe 100-200g lighter than my DIY aluminium frame. But repair cost is higher aswell, though carbon should last a lot longer than aluminium in crashes. I really wanted to make it myself, so I could repair it with stuff I can get locally.

For Version 2.5, I attached light strips to my copter I bough off of hobbyking for a few euros. HIGHLY RECOMMENDED!!! For a beginner, these lights (if you give every arm a different color) the help immensely with orientation. I didn't think it would make such a big difference but it did. I was far more comfortable flying a little bit farther away when I got these lights. Later I even attached a headlight to the front of my copter. After maybe 100m you can't really see the LEDs on the arms anymore (you shouldn't be flying that far away if you don't know what you're doing) and the copter gets really small. The headlight helps with orientation for a much greater distance.
I even added a remote controlled switch that I can turn the lights on and off with my transmitter. It is the small thing next to the BEC in the next picture.

This it what it looked like in version 2.5. I since then have rewired my copter 2 times. The wiring is messy and you shouldn't do it like that.
Today, the wiring is minimal and maybe 50-80g lighter than what you see on the video. It is benefitial to take your time and do it right like I did later. I don't have a foto of it though. I may add that later on.

It looks really nice, doesn't it? ;) I don't want to brag, but I'm really happy how it looks in the dark. With the headlight I am comfortable flying in my garden in complete darkness. I want to know how that works out with a FPV setup :D But thats for later testing. As I said: I highly recommend attaching a few LED strips for orientation purposes, even in the day, if you are a noob. It is only about 50g weight and orientation is one of the biggest problems you have flying when you just start out. It is so easy to accidentaly touch the rudder stick when giving throttle and losing orientation.

These are the only up-to-date pictures:
A little trick is: you don't need 5 servo cables from the reciever to the KK2. It is enough to connect all Signal pins to one another and add one connection between power and ground of the reciever and KK2 (and any other flight control board really). This is the version like it is right now. It has a wiring setup that I am very content with. I used excess wires (the servo extension wire from the tail servo was too long, and the wire from the light switch aswell) to wrap them around the other wires to keep them tidy.

What you can see below the bottom plate is a tiny camera that I already owned. It is nicely protected (the battery is attached below the camera, so it is protected from all sides) and captures good enough video. I was surprised how little jello I got without even balancing props or motors. Im really happy how it turned out.

This is it! The all up weight with a 3700mAh 3S LiPo and the camera and lights and everything is just over 1kg (1030g), with 2200mAh batterys its 100g lighter. It flies nice with that weight, though it is a little bit more acrobatic with my 2200mAh 3S batterys, no big deal though. You can flip it easily with 1kg of weight.
With the 2200mAh batteries i get 8 mins flighttime (normal flying, a few flips and loops, but just flying around aswell) and about 12 mins with the 3700mAhs, this is with the lights on. You can add about 20 seconds when you turn the lights off. I ordered 2x4S 3000mAh to test how it feels with a 4S setup, I can't wait for it. ;)

If you wanted to purchase Fatshark Attitudes from the EU Warehouse from HobbyKing: Be angry at me now. I got the very last set. ;) It may be a little early to start FPV, but I really can't wait for that experience. I would've waited 1-2 months before buying them, but I saw that Hobbyking was out of stock soon and I knew that it can take months to restock. On ebay and all the other stores i've seen them (in europe, I don't want to have the hassle with toll fees and such...) they were much more expensive. Even used on ebay they cost the same as new from HobbyKing, so I bought them there.
I was surprised that the FPV gear only adds about 40-50g of weight, so it shouldn't be noticeable.
I will report how FPV flying goes when I get to it! :)

Last but not least, I made a little video:
It shows pretty much the same pictures like here (it is a bit outdated...) so just scroll ahead to the part where I put the onboard footage from my little camera! I rendered it with a little low quality. The footage itself looks a bit better than it is on the video, but I have a very slow internet connection and uploading this video took me about 1.5h...
It is no spectacular video but it shows what I could do with about 1-2 weeks of flight experience. These parts are auto-level only, but only because I was intimidated crashing my copter in an open area. I kept the acro-mode practice in my garden mostly.
These are just normal practice flights, so the footage is not that great because of the fast actions. It looks much better when you fly slowly and turn slowly, but as I say in the video: I focused on learning and not capturing great video.

Today I feel like I'm much better, e.g. I fly acromode only and don't get confused by orientation as much and I can fly facing every direction and I'm able to perform basic aerobatics. I use the self level switch only as an "oh crap, I'm about to go down"-switch, to rescue myself from time to time, wich is another good tip for a beginner learning acro mode: Keep a finger on your mode switch, it can come in handy. ;)
When you begin, remember to let the copter face away at all times. Remove the rudder pretty much out of the equation. Add it later, when you get a little bit more experienced.

A last word for all beginners out there:
It is really not that hard at all (sadly, just a little bit expensive...), and you can get all sorts of information, inspiration and help on youtube and forums like this one. The size of a process like building a Tricopter seems intimidating at first, but once you get to it and ordered the parts (let the forums help you pick the right gear, if you aren't sure!) everything should come together smoothly. I was surprised how well it went for me. You only see the "help-my copter doesn't work"-threads on the forums so much, because guys who have a working copter, don't need the forums. :D So I think people with problems are not the majority.
The build process just takes a couple of hours, and I'm not the greatest solderer and mechanic either. Learning to fly heavily depends on you. I play computergames from time to time and already had the feeling for a "controller", so it didn't took me as long as expected to learn some things at all. I don't consider me an experienced pilot, but I can maneuver my copter pretty well I think.
My father seems to have a bit more problems with e.g. moving the throttle without touching the rudder, but in a while, he will have figured it out, too. :)

Thank you very much for reading! If you have any questions regarding anything you just read or see, please feel free to ask. I will be monitoring this thread. I will also keep you updated on my journey to FPV flying! I also missed to add an offboard video from the copter flying. I may add that later.
I would really like to know, if beginners read this thread and maybe got a little bit of inspiration of my work. If so I would be very happy to get a comment from you! :)

Thanks again for all your support and kind words! I really appreciate it.
If I have made any errors or something should be taken out or so, please point that out. I'm a bit short on time and I don't know if I can proofread this post in time.



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Faster than a speeding face plant!
I think most people buy multiple receivers so they can have multiple copters or planes. I know I do. :)

4S is too much for a beginner pilot/builder. Start out with 3S and work up.

You will crash. You will crash and you will break your copter. How badly the copter breaks is related to how heavy it is. Keep it light and that means 3S for starters. Lighter copters have less inertia in a crash. The less inertia in a crash the fewer parts break and go spewing off your copter frame when you crater it. The lipo is the heaviest single part. Keep it light and your crashes light.

Go 3S with at least a 35C rating. Again keep the copter light. Learn on an 1800mAh 3S 35C lipo. That 3000 won't give you more air time. It will just hammer your copter to bits when you crash making repairs more expensive and more time consuming. When you are learning, more mAh just means more cost and less flight time due to the time it takes to repair the copter.

It's counter-intuitive, I know. Trust me. Heavy batteries on your first copter for the first 60 days will just pulverize your copter into toothpicks. It will take you 2-3 weeks to learn to hover with a small lipo. A large heavy lipo just makes it that much harder.

Afro ESCs are the best HK offers. 20A will be fine on 3S. Use a ubec or pololu #2107 voltage regulator to power your flight controller if your ESCs don't have a bec.

The KK2 needs to be flashed to later firmware. Get the USBASP with 6 pin adapter. The stock firmware is aweful and you will hate it if you try to fly it.

If you use 3.5mm bullet connectors to connect your ESCs to power and to connect your motors to the ESCs you will need at least 15.

You will likely need some XT60s.

If you don't use the KK2 voltage detector you will need to buy one that connects to the balance port on your lipo to warn you when you hit 3.5v per cell or so.

Look at the Accucel 6 charger. HK ships this all over the world and is probably their most popular charger. It will do 3S or 4S just fine. Don't forget the AC to DC power supply.

NTM brand motors have a mixed reputation. Buy at least 4 for a tricopter, you will need a spare someday.

Buy at least 5 full sets of rotors. Get some in bright colors and put them on the front of the copter so you can tell which way is which while you are flying. Strategically placed 12v LEDs (3S again) will also help you maintain orientation on your copter which is critical while you are learning to fly.

Don't forget heat shrink and a heat gun and don't forget a battery strap.

Welcome to Flitetest!


Hi cranialrectosis,

thank you very much for your detailed explanation.

XT60s - yeah, I had a XT60 to 3 pairs of Bullets Y-harness thing on my list i forgot to mention here.
For the USBASP: I have an Atmel STK500 Board with wich I was playing around with some Microcontrollers some time ago. I plug it in via a USB-RS232 Adapter and it has a ISP 6Pin. I think the programmer is Atmel specific and not KK2 specific, right? Then I should be fine on that front, if the flashing software has the option to flash via RS232 and not USB.

I searched a bit further. You are right with the 3S thing. I will now alter my part list and post it again.
Updated part list for 3S setup:

1x Spektrum Dx6i + 1x AR610 Reciever

5x NTM Prop Drive Series 28-30 1200kv / 400w + mounting accessory - Mixed reputation? Means that I probably should buy others? If so, wich ones?

5x Afro Slim 20Amp (SimonK Firmware) - I hope Afros with 20A AND BEC comes back in stock when I'm going to order all the parts.

1x Turnigy 5A (8-26v) SBEC for Lipo - To power my KK2 + Reciever. But I hope the 20A Afros with BEC come in stock before I order...

2x ZIPPY Flightmax 1800mAh 3S1P 40C - Do I need more of those to keep me flying. How long does it take to charge them?
(1-2x ZIPPY Compact 3300mAh 3S 35C - I maybe buy that for later, when I'm able to fly that thing)

1x Turnigy Accucel-6 50W 6A Balancer/Charger - Looks good, thanks for the tip!

2x Turnigy Digital high torque bearing servo 15.8g/3.9kg/0.13sec - The closest servo to the ones proposed by RCExplorer that I could find available at HK. Is this okay? Are 2 enough?

5x set (3 pieces) 8x5 Props - I have no idea wich props to use, I know I should use plastic ones, not carbon. Can u show me props that I can use (they have to be CW & CCW,right?)? I may buy more of these as

1x KK2.1.5

20x pair of bullet connectors 3.5mm

10x 60cm & 10x 10cm servo leads - HobbyKing is out of stock on all servo leads. I will get them off of ebay or something.

18 AWG cable - Have that laying around.

I'm really grateful that you guys are helping me out. It is soo much to learn for a noob like me. I don't want to be spending so much time waiting on shipping things I missed buying and because of you, I won't have to (as much). Thanks a lot!


Faster than a speeding face plant!
I will have to defer to an electronics 'forum heavy' on flashing through RS232. I have the USBASP and that makes my job simple.

Take good care of your lipos. You do not want a fire.

Always balance charge at 1C. Your lipos will take about an hour to charge depending on how much you leave in them. I stop flying when any cell hits 3.7v.

If you charge at 2C your lipo will charge in about 30 minutes, but you put more stress on your lipo.

Don't forget a lipo bag.

HK tends to have a pretty good selection of 8045 cw and ccw sets in various colors. Definitely learn on nylon rotors.

I buy my motors in the US so I don't know HKs selection very well. Ditto with the servo. Several members of this forum will recommend motors from RCTimer. My comment about NTM motors comes from other posts on this forum. I have no direct experience with them.

Hold off on the heavy 3300 lipos. You may find a 2200 fits better. I run Suppo 1450kv motors with 8045 rotors on 3S and I can fly a 3000 but it severly impacts performance. It is stable in the wind and flies ok but a 2200 is more fun to fly on my setup.


As long as it's not KK2 specific, it should be fine. I mean, why would anyone invent the 6PIN ISP again, if theres already existing ones. ;)

Yeah, I'll be sitting with them while charging and place them in a place, where they can't start a fire.
Thanks for the charging tips. Lipo bag seems to be a good idea, i will probably get one of them.
Okay, I was dumb, I just realised what 8045 stands for in the HK listings :D I was looking for "8x4.5" not 8045.

I want a fairly cheap vendor that ships from central-europe. Im a student from germany and don't want to be spending hours to drive to the customs office and have to pay fees and such (I had that beautiful experience once when I bought something shipped from USA). HK Europe seems to be the cheapest solution available to me. So if somebody could point me towards another store with shipping from europe (or even better: germany) or give me an advice for better motors from HK, I would be thankful. But because David Windestål does recommend those motors on, I figure that they can't be too bad for me, can they? I mean, I won't be doing aerobatics in the beginning (at least not of the intended kind :D). But as I say, im thankful for every advice!

I do understand your point with the lipo weight, but I wonder how 105 grams make the difference. The 1800 mAh is 172 g and the 3300 mAh is 277 g. I mean people mount FPV gear and GoPros and LEDs and other things on those copters and all that should add up to more than 105 g. How can they fly (and from what I've seen, those guys got at least 2200 mAh batteries).
I really don't want to sound like a know-it-all and I don't try to dispute your experience (is that proper english? I don't trust google translator.) but I am wondering a bit about that.

I will propably be beginning to order stuff in the next few days (I CAN'T WAIT! :D). It would be great if somebody could make a statement about those motors and servos. I mean, those motors may not be the perfect solution, but as long as they are okay, its fine for me. David won't recommend crap, or will he? :D

I most surely will be documenting my way to a full tricopter with a few pictures. Is there any interest in another "Noob tries to build tricopter"-thread or article? I mean the internet is full of resources about multirotors. I don't know if it's worth the time of other people to read another kind of thread like that. But if there is any interest, I surely want to give something back to the community. You guys are helping me out big time, I'll do what I can to return something!

Thanks again for your quick reply!


Faster than a speeding face plant!
Don't learn with FPV gear or a GoPro on your copter either. :)

Every gram counts in a crash. 100 grams is 10-15% of total weight of the copter.

With those motors you can probably lift a 1200 gram tri-copter. The copter will fly but at 800 grams that copter will feel more responsive and will be much easier to fly. Work up to a heavy lipo and camera gear the way you learn to drive. Most folks learn to ride a bike then drive a car then drive the heavy truck.

Those motors will carry the gear. My suggestion is that you learn light and cheap.

Germany has one of the premier vendors:

They aren't cheap. They sell top-notch gear. The service is excellent.


No, I won't be thinking about FPV in the near future :D

Okay, that's what you mean. I thought you were talking that the tri can "barely" lift that weight. Now I understand your point. That battery was intended for future use, when I am able to fly that thing without crashing too much and want to get a litte bit more flight time. But if there are good german vendors wich sell these at reasonable prices, I can always buy that later. I just wanted to save on shipping cost and waiting time there.

I will definately trying to get that weight down as low as possible. I will try to DIY my frame however, so that propably won't be "down to the gram".

I will look at Maybe buying there. I like to read about shops first, before I buy at them. It also depends on the price. If they are way more expensive, I will buy at HK, but I will pay a bit more for shipping from germany.


Staff member
Hey Nils,

I built my first quad with Suppo A2208/14 1450kv motors. I didn't have any problems with them yet and Suppo seem to be reviewed as good bang for the buck. There are a few shops in Germany selling those besides FlyDuino. I usually order at a shop that is based in my hometown anyway:

Documenting your build is always appreciated in this forum, no matter how many builds we had, we always like to see ideas others have and can help if you run into troubles.


Hi Balu,

thanks for your tip! The A2208 is not available at meinkopter unfortunately, but it is at flyduino. I will be thinking about buying these parts (Motor, ESC, Props) there, because I suspect I will be forced to buy those more frequently (crashes etc.). These shops propably wil be shipping these things faster than HK does. HK will still be my source for all the tiny bits, connectors and such, as it seems to be the only shop wich has nearly everything needed.

Documentation: Okay, I can definately do that. I'll post a few pictures and a short explanation. And I will be filming my maiden. So if something doesn't go to plan, I don't have to chuck new props on and then crash again, just to record a video for you to see whats happening. :D

I nearly can't withstand going out and buying everything now, but I also like to take these kind of things a bit slowly and sleep a night about it. I made the decision to build that tricopter 2 days ago. Even though I am looking at them for over a year. :D

Thanks to you two guys. I'm amazed by your response time. This community really is welcoming and helpful!


Hello Guys,

I ordered everything from HobbyKing. I ended off with the NTM motors, because sadly, flyduino had only one of the motors I needed left in stock (i wanted 4-6) and meinCopter had none of them. I ordered 6 of them of HK now, so even if one or two of them have bad bearings or something, I can continue building.

Now i'm waiting for the package to arrive and I thought about one question:
Because my ESCs don't have BECs, I bought an external BEC. But where do I have to connect it? I read everything I could find, so I know that the reciever can power the KK2 and vice versa with the restriction that M2-M8 on the KK2 aren't connected to the power that the KK2 operates with. M1 can power the KK2 and can transfer the power to the reciever. If I power the reciever, it'll power the KK2 and M1. But for the servo on M4, do I need an extra Y-harness to connect that to power aswell?
Second question:
To get power to the KK2, I either need to provide power to the reciever, or directly to the M1 port of the KK2. Because I will need every port of my AR610 reciever except for the BND/DAT port, can I stick the BEC into that bind port? Will the bind port transfer the power needed for the reciever and through the reciever to the KK2?

Thanks again for your help

I figured this information could be usefull for others:
The FlashingTool for the KK2 board supports the use of many different flashing devices. My STK500 Board appears in that list. So if you have an other ISP Programmer, search in that drop-down menu for it. 99% of the time, you will find something for your needs.
If you don't have a USB ISP, connect the RS232 to USB Adapter (if you don't have a native RS232 port on you PC) first before starting the programm. This way it can detect the new port and will show it in the port drop-down menu.
Generally speaking, the KK2 Flashing Tool works with AVRDude, so everything that is compatible with AVRDude, should be compatible with it.
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likeig the thread so far. i live in holland and have the same dilema as you. please tell us about your ntm experience once you have them as i am looking for motors too! :)


Hi khostr,

HobbyKing was fast, I ordered sunday and it arrived today. So no complains on that part. Everything that I ordered was in the package.

I unpacked 3 of my 6 NTMs and could not detect any slop in the bearings like other people mentioned. But because the package from HobbyKing arrived today and I got home late from university, I couldn't test much. I only tried to start up one motor directly via BSC + Reciever. The motor worked, but if it is vibration free with props on and has enough power and so on and so forth, I can't test now.

I'll keep you posted, if I get that thing to flying, but it can take a while, because I don't have time to fiddle with it for the next couple of days (not even on the weekend :()

If someone has the same question as me earlier, I simply tried it: Powering the KK2 + reciever via the BND/DAT port on the reciever works fine.

Thanks again to all people who helped me. It's looking like I'm maybe going to have a nice Tricopter in a few days/weeks. ;)


Faster than a speeding face plant!
Most of the negatives I have read about NTMs is about durability in the long term.

Be VERY careful with them and they may work out just fine. I advise that you not crash them in sand. :)


at HobbyKing I saw some customers chatting about bad bearings.
These motors are cheap, so if they last half as long, but cost half of others, I'm not too angry :D
If they don't work out, I can always get some others, but thanks for your warning. I would have bought others, if they had been available...

Thanks for your reply,



Hi guys,

I put the thing together yesterday. I made it out of thin wood for the frame and aluminium square tubes for the booms. The take-off weight including everything (battery, motors, elektronics, frame, booms) is 880g.
I didn't have the opportunity to fly it yet, but I tested everything I could indoors (not flying though).
I hope when I get home after university, I will have the opportunity to fly it. It is windy at the moment, though.

Thanks again for all your support, without you, it would've been a lot harder/more expensive/time consuming.
I will definately post some pictures of it and describe my thought process a bit. But I have very little time at the moment and I want to wait until im sure that it flies and that it is reasonably optimized. I have to learn to fly it, too! So it may take a few weeks for that post.
Thanks guys,


Senior Member
On your first flight, stand a few feet away from it! Don't be too close! And don't be afraid to cut the throttle and let it drop BEFORE it gets somewhere you don't want it to be. Keep it low and slow for your first few flights and get used to how it reacts, what inputs do what, etc.


Hi guys,

firstly I want to adress every noob out there like me:
I had the same thoughts that you probably have right now:
- Building will be time consuming and I'm a little afraid of flashing the flight control board and so on...
- Maidening that copter is really hard because all the gains will be way off (thats what it seems to be, regarding the amount of forum posts and youtube videos).
- Flying without auto-level is incredibly hard because you have to be so quick to compensate the actions of the copter.

Flying a copter like this is not really that hard! If you take it slow and fly low you will probably not break it if you cut the throttle in a tricky situation. Even with auto-leve off, one can control this thing quite easily. I flew maybe 10 minutes today and I could fly that thing stable at about 2 metres and controlled it to where I wanted it to be. I kept it nearly always in front of me facing away though, not to get confused by reversing the controls, when it flies heading to me.

What I don't want to say is that it's easy to fly like the dudes on FliteTest or youtube in general. But it was easier than I expected and the flight without the auto-level was way way easier than I thought (I thought that that was really for the pros, though). I tried it, because I knew that I wouldn't be able to sleep tonight if I hadn't tried it. :D Even though I was a little scared to flip that switch at first.

You only read about people having problems with gains and settings and flashing and so on and so forth on the forums. But regarding the smoothness of my build, I can say that anyone can do it! I may be incredibly lucky, but I rather think that you only read about problems on the forums, because you don't really need a forum if there's no problems. Don't let the appereance fool you! It is not hard! You need a bit of time and have to learn to solder if you can't, but otherwise these days, it's made incredible easy by the Flightcontrol and ESC companys, to have everything plug and play without much fiddling around. Be careful with the polarity of power connections and watch a few build videos on youtube and then: YOU CAN DO IT TOO!

khostr: Sadly, due to the rain and the darkness, I couldn't film my maiden. I weatherproofed my KK2 with a plastic bag though and flew it a few hours ago. It was great! Really stable and powerful, despite not touching the gains one bit!

Ace2317: Thanks for your tipps, I think I did everything more or less right, even though I see your post after my maiden. :D

I really want to post a litte bit of a build thread, where I can present some of the ideas I had while building this tricopter. But because I'm a little short on time and that post can take a while for me to make, I will show you some of it here.
I have to say this is still work in progress: A german vendor somehow shipped a parcel from a german warehouse to me via airmail, even though I'm living in germany. I don't know why that is, but I have to wait for servo extension cables. I didn't want to wait on those stupid cables, so I DIY'ed one (the blue things on the back boom). I know this is not a great idea, because this connection is so loose, but it worked for my maiden and it will have to work until I get those cables... I don't want to solder those cables together for these few days. Also the power distribution is WIP. I bought the XT60 to 3 pairs of bullets harness thingy that David from rcexplorer recommended. It may work for him, but because I made a cable extension for the ESC->motor cables (so that I don't have to extend my ESC servo cables to the KK2), I didn't need so much cable to connect the ESCs to power. I simply folded and zip-tied the harness together and stuck it in my frame. I'm loosing a few grams there but thats no big deal. It just looks ugly.

I resized the pictures to 900x600. I didn't want to upload 7MB files per picture. :D

IMG_2802 low res.jpg
Top view with the DIY servo extension. DO NOT TRY THIS. IT WILL FAIL AND BREAK YOUR COPTER. IT WILL PROBABLY BREAK MINE... Inside the aluminium booms are the ESCs (Afro slim 20amp). I made a 3x2mm male bullet to 3x3.5mm female bullet adapter/extension cable for the connection between the ESCs and the motors, so I didn't have to extend the servo cables running from the ESCs to the KK2. I simply plugged them in directly. The ESCs sit really near to the frame inside the arms. All my connections are bullets, so if something breaks, I can replace those parts with stock ones without much hassle. I know that more connections mean more failure points. I'll see how that works out. If I get too much failures, I may crimp or solder everything together.

IMG_2806 low res.jpg
Front view with the ugly power distribution. I probably will change that in the future. It works for now. The servo connector thats loose on the left is connected to 5V from the BEC. I may connect some LEDs to that in the future. The battery is mounted sideways below the frame. The CG is more or less right, so I fixed the battery there with rubberbands.

IMG_2804 low res.jpg
The landing gear made from really big zip ties. It works really nicely. They absorb the shock of a little rough landing quite well. They even are adjustable in height! They could be a little big bigger, though, because I mounted the battery below the frame. On a hard landing, the battery touches the ground. I may add some things inside the zip ties, to limit their bouncyness.

IMG_2805 low res.jpg
Folded up nicely for transport.

I have an alu case for an old broken heli I had. I may be cutting the foam out, that I have a nice case to transport that thing without damaging it.

When I look at the length and the information of this post, I'm wondering if I really should make another thread as a "build explanation". I covered just about everything that I made different from the older (2-2.4) versions of David on What do you think?
When I made the copter, i wanted to take many fotos, but now when I look at it... If your in the flow with soldering etc. you forget the pictures a bit... :D I have a few more though, so if there is any interest...

If you have any questions regarding my build or something, please ask! Im greatful for the support of the community and I really want to give something back! :)
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Looking real nice! good job on the build and maidening it! Im still curious about the motors! how are they holding up? no bad bearings?


Hi khostr,

thanks for your compliments. Building it was really fun and maidingen it too!
I have maybe 30-45 minutes flight time right now, so I can't say if the motors are "holding up". I couldn't detect any slop or funny noises when turning the motors with my fingers, and when I power them, everything seems normal. But I wasn't warned about bad bearings, I was warned about the lifetime of these motors. And how long they last, I can only say in a couple of months. So far, I'm pretty happy with them.

For anyone interested: With a 2200mAh lipo and 900g of weight, I can fly about 8:30-9 minutes (hovering, slow pace flying, a little bit of throttle stick banging to let it jump towards the sky). I stop flying at 3,6-3,8 Volts per cell, so I have currently about 800-900mAh left in the battery. I may be lowering the voltage alarm threshold a bit, so i get a little bit more flighttime, before the beeping starts. Not using 35-40% of your battery may be safe, but I think I can get to 9-10 minutes flying and I'm safe aswell.

I mounted a really small actioncam (noname, couple of grams - not noticeable when flying) that I wasn't afraid loosing and I only had a little bit of jello in the picture. I suppose that is, because with my props there were no fitting adaptors to fit my motor-shafts. I'm using an adapter far too large, so my props should be really really unbalanced (uncentered). I can't notice that during flight however, so I don't have to fix that immediately.

I may post an on-board video soon, but that flight was in my backyard, and I don't want to show that to everyone on the interwebs. If you really want to see it, I can go to a more public place in the coming days, and film there. Let me know!