Now I'm about to assemble my first frame. This topic is quite new and popular. Instead of retelling what you can read online, I’m going to tell you about the innovations, which have been introduced in this design. Also, I would like to recommend all hobbyists from Nizhny Novgorod who have all types of copters in possession, including mini FPV 250, to refer to this new VK.com community: http://vk.com/copter250. Please, join now!
And one more thing: in the end of the post you can read about simulators, which I use.

It is not quite so long since I got bitten by the copter bug. I started with Hornet 460; next came DJI F550 and Naza M v2; for winter training I purchased Galaxy Visitor 2.
What made me want to have this type of copter was the following video:


Many guys must have viewed it by now.
The Internet is cluttered with information on this kind of quadcopters. This has to be one of the most discussed topics. I began to collect information.

My decision was to build a frame on my own. I found information about frames here: http://untestedprototype.com/ and got down to work.
If you have a 3D printer, you can view a bunch of good and not quite so good things here and enjoy HD quality: http://www.thingiverse.com/search/page:2?q=mini+250&sa=


What looked really interesting to me was the structure of the frame - the beams and the base frame, on the top and at the bottom. This is what it looked like:








As seen in the figure, a roll (in case of traditional arrangement) will give the battery a stronger leverage and therefore may cause moment increment. You’re going to have balance it out with the help of energy produced by the battery.
Well, I’m going a non-traditional way!














I built a prototype. As you can see, the beams are made of composite, external parts – of glass fiber laminate, and the core is made of plywood and serves as reinforcement. The frame was to be crafted from fiber laminate too. What made me want to use these materials were the low cost and a large number of parts available. You can get as many as you want and cut to your heart’s content!


Most of the information concerning assembly and parts is available on Yulian Gynevsky’s channel. I guess, there are lots of people who are familiar with his Youtube channel https://www.youtube.com/channel/UCrRvbjv5hR1YrRoqIRjH3QA and VK.com group http://vk.com/rcschoolmodels. Thank him and all community members for all that! I chose not to browse for parts and bought Yulian’s stuff instead:
motors
DYS BE1806 2300KV Brushless Motor 2-3S for Mini Multicopters
Product http://www.rcfair.com/en/product/1559651/


ESC
ZTW Spider Series 12A OPTO ESC With SimonK Program
Product http://www.rcfair.com/en/product/1560209/

Flight Controller
OpenPilot CC3D Flight Controller Staight Pin STM32 32-bit Flexiport
Product http://www.rcfair.com/en/product/1559819/

BEC
http://ru.aliexpress.com/item/Free-Shipping-Andoer-1-2G-5-8G-Micro-BEC-w-CNC-Enclosure-12V-3A-Output-4S/32291179434.html

AV receiver
Boscam FPV 5.8G 400mW AV Receiver RC805 with Transmitter TS353
Product http://www.rcfair.com/en/product/1567194/

Camera
1/3-inch SONY CCD Video Camera (PAL)
Product http://www.rcfair.com/en/product/103395/

Propellers
Gemfan 5x3 Inch Plastic 5030 Propeller CW/CCW For 240 250 Frame
Product http://www.rcfair.com/en/product/1560672/


Batteries
Turnigy nano-tech 1300mAh 3S 45~90C Lipo Pack
Product http://www.rcfair.com/en/product/114064/


And stuff, which I already had:
Receiver
FrSky X8R 8/16Ch S.BUS ACCST Telemetry Receiver W/Smart Port
Product http://www.rcfair.com/en/product/1077476/

Transmission module
FrSky DF 2.4Ghz Combo Pack for JR w/ Module & RX
Product http://www.rcfair.com/en/product/101892/


My equipment is quite simple: Fly Sky 9Х

So far only Monitor 7”; now I have to choose between goggles and a helmet.

When my parts arrived, I found a ZMR 250 frame, H250 ZMR250 250mm Carbon Fiber Mini Quadcopter Multicopter Frame Kit
Product http://www.rcfair.com/en/product/1559650/

and I bought it even though the frame that I had ordered was already under construction.

I’m not going to enlarge upon the construction process, so if you want a bit of information on that, please, view Julian’s video lessons. I’ll just focus on what I believe are the most important things.



I decided to place the ESC, BEC and distribution board inside the frame. I had to make spacers. I could have 3D-printed them, but I suddenly thought myself smart and crafty enough to make them out of a piece of foamed PVC. Don’t do that! It gets too soft. Eventually, I had to replace them with hand-made 1mm PET spacers.



The aesthetics was above all to me, so I chose black and red as basic colors. That was my choice of cable braiding.


I still had doubts about the arrangement.


However, when I mounted the battery and held the frame in my hands, I concluded once again that knowing theoretical mechanics was a must, even though it was a past-century experience for me. A ‘traditionally structured’ copter won't miss a chance to tip over! The only thing I didn’t like about the 'non-traditional' arrangement was the likelihood of damage of the lower frame during crash; later I realized that trying to avoid that was pointless, because every flying object had to crash one day. I wasn't going to put it up as a museum exhibit!
Next thing I had to do was to fix on the frame all pieces of equipment I had. I left a 10mm gap between the frames, cut all the wires short and lacquered all connections, boards, etc.


To minimize the risk of short-circuit and to protect the inside the frame from dust and dirt, I cut two liners out of a 0,5mm piece of PET.


and made holes using a soldering iron with a sharp nozzle fixed on it.

I do realize that ESCs need cooling, but I’ve seen lots of copters with enclosed casings. Let’s see how it’s going to work.

I also had to cut an extra mount for a recording cam out of a piece of glass fiber laminate, because the standard holes were now at the bottom.


Now let’s get down to the décor. I made a bumper for LED lighting and a side dust baffle of PVC and taped them up. I had some red reflective tape at hand, and I chose red LED tape as well. Then I fixed the removable bumper to the pillars with double tape.







Now my copter weighs 550g without a cam (has not arrived yet)

It is slushy outside, so I don’t think it is the right time to test-fly it, and I did a bit of it at home:


I didn’t do any PID tuning. Upon Sergey’s advice, to tune the controller, I used a Hobbyking 250 frame with DYS motors. Definitely, I’m in for quite a bit of tuning and balancing, and I guess you all know that this is just a beginning of the assembly. I should specifically note that this arrangement requires that you “turn” the controller 180 in the settings in case you are going to turn the controller itself on your copter.

Now I’m in for a whole load of training, crashes, repair, adrenalin, disappointment and, definitely, joy! Drones make love, not war!

And now let me tell you a bit about simulators. I guess there are lots of similar posts on this stuff out there, but it won’t hurt anyway. I didn’t care about licenses, so I downloaded freebees, caught a virus, underwent treatment, and here is my little sum-up:

There are two ones that I can term as decent:

1. HELI-X4 (demo)
Advantages:
• good graphics

• excellent flight physics
• features training regimes.


Disadvantages:
• features only one copter type

• no FPV (no 3D)
• you have to reload it every 10 minutes
• only one scene
• lazy copter (not 250 mini)
Conclusion: very good except for the lack of 3D


2. AeroSIM-RC (demo)
Advantages:
• lots of copter types featured

Lots of scenes, including 3D,
• FPV
• excellent training regimes!
• graphics not bad at all
Disadvantages:
• you have to reload it every 2 minutes
• bad physicss (once you cut throttle, it rolls)))
• the graphics are not good either, but better than in FMS anyway.

Conclusion: the training regimes are all fun and exciting!!!

Both have clear and easy flight control and can be operated via a usual adapter. USB Simulator Cable XTR/AeroFly/FMS
Product http://www.rcfair.com/en/product/102826/


Here are links to the simulators: http://vk.com/copter250

Wish you a fair wind!

Это перевод. Оригинал на русском здесь.