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Multirotor MegaThread - They're UFO's, Not Drones!

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Mohonky

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[Image: Banner]

Why a Multirotor OT?

Multirotors have been gaining an ever increasing presence in the past few years both within the RC community and outside from those with a casual interest right up to professional photographers and film makers. But there exists a huge range of multirotors, frames, components and accessories that can make getting into this segment of RC, either as a hobbyist or a professional; rather overwhelming.

As such, in this thread we're going to start from the very basics of choosing the correct multirotor and it's components to help users get the most out of their airframe for the type of flying they'll be doing, advice and tips on learning to fly as well as covering numerous other aspects of multirotor ownership.

It is important to note, that while I myself own a few frames and have experience flying both Line of Sight and FPV, I'm not a one man encyclopaedia and I don't have an answer for every question, particularly as this is a relatively new segment of the RC community and is experiencing exponential growth due to the opensource nature of the software that allows for ever increasingly complex levels of automation and flight characteristics. Because of this, we'll all be learning something a long the way and in doing so we may need to look to other sources of documentation for more specific questions regarding flight controllers and software. We'll all be able to contribute here either with our own knowledge or by providing links to other resources for those needing more in depth knowledge on some specifics.

So having said that, a quick look into the history of the multirotor to help understand what a multirotor is and why there has been such tremendous growth in this segment of RC.

[Image: Multirotor]

What is a Multirotor?

A multirotor is, as the name suggests, an airframe that achieves flight through the use of multiple motors. We've had airframes that could fly before though, so why the big deal with multirotors vs Helicopters or Planes and more so, if the multirotor has any benefit over those other forms of aircraft, why only now are we seeing the growth in popularity of the multirotor?

Both can be answered by coming back to the fundamental flight characteristics of the multirotor. Put simply, it was a software problem.

While the idea of having multiple rotors to suspend an airframe in the air seems like it would inherently be more stable than the single rotor of a helicopter it's actually not. In order to maintain level flight a multirotor must constantly adjust power output to each of its rotors to maintain stability. To then actually pitch, roll or yaw; requirements to make the multirotor move through the air and maintain stability an even bigger problem.

Helicopters are able to overcome this by use of a mechanical linkage known as a swashplate. A swashplate is a mechnical device that is able to change the pitch of the blades as they rotate; by altering the angle of the swashplate a pilot can alter the pitch of the blades of the helicopter and in turn achieve lift, pitch and roll. The addition of the tail rotor is able to counter any rotational torque applied to the helicopters airframe and enable it to yaw when required.

Multirotors do not have any such mechanical linkage. That's not to say it's impossible, but this means a swashplate per rotor all needing to be controlled by the pilots input. Essentially, it's just too complicated to be practical.

Hardware and software has come a long way and the introduction of the ESC (electronic speed controller) in combination with the necessary PCB (namely, the Arduino board) containing the software (the electronic brain required to control each ESC individually) we are able to achieve stable flight with the multirotor, and yet not only that, but at prices attainable for mass market consumption.

This is of course at it's most basic level. Looking into the current state of multirotor flght controllers, even in the short time that multirotors have been on the mass market, the opensource nature of the software found in many flight controllers has mean't that the collective pool of clever dicks out in the wild has managed to refine and expand upon the multirotors capabilities. The multirotor isn't just an airframe that achieves very stable flight, but one that is capable of so much more; particularly in terms of autonomy and for the budding photographer or videographer, the ability to get photo's and video that would normally require one to be in a helicopter / plane or in some instances, simply not possible at all.

Which Multirotor for me?

We'll discuss not what frame to start with, but what our ultimate goal is and the pro's and con's of each frame.

There are a number of multirotor configurations that lend themselves better to some tasks rather than others and so it's important to understand what you ultimately plan on doing with your multirotor. These are the most common multirotor configurations and all lend themselves to slightly different characteristics in terms of flight and lifting capability. Once you have decided on what sort of use your multirotor will serve, it's time to pick the appropriate multirotor layout.

40a5c03d318a2bbd_zps1jgelnen.png

Tricopter: this layout fits an unusual position in the multirotor realm. It is the only one where a servo maybe used to 'tilt' the driving rotors. This enables the frame to perform Yaw movement with more responsiveness and speed, not as quick as a helicopters tail rotor, but definitely more substantial than you're typical multirotor. With only 3 rotors, this frame has the least lighting capacity so is likely not the frame you really want to use if you plan on attaching your GoPro or other recording devices. However these can still comfortable be fitted with FPV (first person view) gear.

The extra Yaw capability makes this a great multirotor for sports flyers wanting to perform more acrobatic manuevers.

Quadcopter: this is the frame most of us will be familiar with. Utilising 4 rotors, this particular airframe is a very good jack of all trades. More stable and with greater lifting capability than the Tripcopter, a Quadcopter makes a great middle ground for those wanting something with the capability of flying acrobatically as well as doing moderate lifting duties carrying devices like the GoPro as well as fitment of gimbals etc. While you can get larger quad layout airframes, you may find adding extra flight sensors, controllers and other accessories at times a tight fit.

This is also the frame most commonly used in 'FPV Racers,' smaller airframes with higher RPM motors capable of serious speeds and acrobatic ability to perform rolls and flips.

A good all rounder.

Hexacopter: this is the beginning of the 'heavy lifters.' The Hexacopter is the choice for heavy lifters who don't want to move to the Octocopter. If you're ultimate goal is to mount a camera, whether a smaller point and shoot or reasonably sized DLSR, this is the minimum you want go as the increased lifting capability and general stability of these frames will be highly desired.. With 6 rotors for increased lighting capability and generally larger prop size and ability to fit larger motors and more powerful ESC's to match, anyone with aspirations of serious photography / video filming should consider this as a minimum. These are usually larger frames so fitting extra sensors and accesssories (Gimbals, IR controllers for operating your camera in the air etc) shouldn't be too much of an issue and you should have enough room on the airframe to keep your install relatively clean and uncluttered.

It is also worth noting that the loss of one of the rotors either by ESC or Motor failure may not necessarily lead to a catastrophic loss of control to this configuration of airframe. Flight may still be possible, a loss of Yaw control maybe noticeable but getting a safe return of the airframe may still be possible.

*While most FPV racers are Quadcopters, there are a few small Hexacopters used in FPV racing also. Because 100+ km/h just isn't enough for some people.

Octocopter: basically all the pros and cons of the Hexa, the Octo is the choice for serious photography and video needs; it is easily able to carry larger payloads with great stability, the Octocopter is the choice of Professionals and Enthusiasts alike. This is not the frame for those looking for acrobatic or sports flying, it is purely a work horse.

Like the Hexa, it can also maintain stable flight even in the event of a rotor failing, in many cases 2 or more so it offers some safety for those hauling expensive equipment.

So, having picked the best frame for our intended use, it's time to pick probably the most vital component of our multirotor......


Flight Controllers

Like choosing your choice of multirotor airframe, your intended use of your multirotor can influence which flight controller you choose. The basic functionality of the flight controller does not change from one unit to the other, their primary function is to control the speed or each rotor, keeping the airframe in the air and stable. What does change is the feature set of each controller. While the majority of controllers offer some level of autonomy to near full autonomy through the integration of optional sensors, some of these flight controllers handle autonomous flying better than others while other flight controllers provide smoother and more responsive inputs making them excellent for acrobatic and sports flying where the pilot is seeking the thrill of the flying rather than taking a backseat and letting the flight controller take the wheel.

The Arduino board and Opensource software are two of the factors that have allowed for the exponential growth in the multirotor sector and there is a collective effort out there to constantly update and expand upon the multirotor source code. For coders and programmers, this open nature won't be too unfamiliar or complicated to pick up, for the regular user, this can be bit of a dive into the deep end; but don't fret, there is plenty of documentation out there and so long as you don't go making ill advised changes to the flight sketches and stick to the tried and tested ones, there shouldn't be any need for you to get involved here, just stick with what is known to work and update when the later updates are released and known to be as reliable as possible.

Most of the boards you encounter will be Arduino and Opensource based with few exceptions. How well they perform varies from one flight controller to the next.


This is not all of the flight controllers, but some of the more popular.



DJI
http://www.dji.com/

SKU092321_1_zpsxtv2eie5.jpg

Even if you don't know who DJI are, you probably know their most popular mainstream product, the Phantom. DJI are the biggest commercial name in the multirotor business, if everyone else is Android, DJI are the industries Apple. Whether it's their mainstream line of Phantoms, their individual flight controller line Naza or their larger commercial line of Ace or Wookong systems, DJI position themselves as a company with a solid, simply to use flight ecosystem for the beginner to the professional.

For those after the simplest plug and play system straight out of the box with room for expansion and are interested more in the opportunities multirotors can afford them in aerial videos and photography, this maybe flight controller to consider for your multirotor frame.

This is commercial hardware and software designed for ease of use. If you have limited computer knowledge or are looking for a flight controller backed by a big manufacturer with warranty, this might the one to go with.

Arducopter
http://www.arducopter.co.uk/


apm-2-6-mega2-6-flight-controller-ublox-neo-6m-gps-power-module-ardupilot-c_301263019596_zpsjemqhm2v.jpg


Like the rest of the boards in this line up, Arducopter is opensource. Arducopter has a very powerful suite of features for automated flight and of the opensource flight controllers, it arguably has the most accurate and reliable automated features, rivalling that of DJI at a considerably lower price point. Ths software is also relatively easy to setup and use with a clean and easy to navigate GUI.

Flight Modes

-Acro: Full Manual

-Stabilise: On release of cyclic input, airframe will return to level flight (will still drift)

-Alt Hold: Airframe will maintain altitude.

-Loiter: Basically skyparking. Airframe will maintain position and altitude.

-Drift: Fly airframe with aeroplane characteristics

-Circle: Airframe circles a point of interest maintaining a focus on center of point of interest.

-Brake: After releasing cyclic stick input, airframe will come to a stop and stabilise in position where input was released (essentially enables Loiter after stick input)

-Follow Me: Does what it says. It will follow

-Return to Landing: Airframe will return to point of take off.

-Sport Mode: Will maintain Altitude and a fixed roll, pitch or yaw angle. Basically for panning shots.

-Guided: Airframe is instructed by commands via laptop / tablet and interactive software

-Auto: After selecting waypoints, the airframe will navigate along a path to each point. Certain tasks maybe incorporated into this mode like taking pictures, gimbal direction, loiter, point in specific direction etc.

*Some flight modes may require additional sensors or other hardware



CC3D

SKU153975-38_zpsw94287r8.jpg

CC3D has largely disappeared now despite the fact the hardware still exists and is being manufactured the original OpenPilot software is becoming less common as pilot move over to Librepilot. Librepilot contains many of the original founding members of the Openpilot software source and is still being developed today.

Flight Modes

-Rate Mode / Acro: full manual

-Angle: Will not allow the airframe to exceed set angle. ie. Airframe cannot become inverted, will reach maximum angle and not allow it to exceed that.

-Horizon: A mix of Angle and Acro. Smaller inputs will maintain Angle mode, larger inputs will allow the airframe to perform as if in Acro mode, however when reverting back to smaller inputs or releasing cyclic, airframe will self level.

Position Hold and Return to Home are possible with some modification and additional hardware.

Naze32

55819_1_m.jpg


Probably the most common board on the market today for FPV pilots and racers; designed to be an Acro board that did away with unnecessary features and bloated software code to give pilots the fastest, most precise flight input possible. This pursuit has led to a variety of hardware and software configurations that have been updated and redesigned at a staggering rate.

For the purpose of this description I won't be going into depth on the individual boards (of which there are many) available nor the many offshoots of software these are designed to run.

MultiWii

photo_zpsiocimezi.jpg

Interestingly, MultiWii is so named because the original iterations used the gyro and acccelerometer from the Wii-Mote and Nunchuk. Yeop, Nintendo actually inadvertently provided hardware for multirotors.

MultiWii is one of the oldest flight controllers around. Naturally both the hardware and software has undergone multiple iterations. Currently, MultiWii is a good choice for users wanting to fly full acro (manual) or automated as it features a suite of automated modes found in Arducopter and DJI systems. It should be noted though, that while this board and software is capable of many automated flight modes, these shouldn't really be relied upon in the same way as Arducopter or the DJI series of flight controllers.

Modes like GPS Hold where an airframe should remain stable in the air and 'hold' it's current position and altitude is not as stable or accurate as that found in other software and you may find the airframe drifting around or rising and dropping. Arducopter and DJI excel in these areas with excellent position holding capability.

In saying that, it's not that the mode doesn't function, it's that if such a mode is important to you, you may want to consider other boards as these modes are better executed there.. Otherwise, automated flight is capable on these boards and the source code allows a lot of flexibility between manual and auto flight modes making it an excellent all rounder.

Boards like the Paris v5r3 is also an excellent board as where other boards require you to 'add on' extra components like FPV OSD (first person view on screen display), voltage meters for OSD and other features, all of this is already ready to go on these boards.

Flight Modes


-Rate Mode / Acro: full manual

-Angle: Will not allow the airframe to exceed set angle. ie. Airframe cannot become inverted, will reach maximum angle and not allow it to exceed that.

-Horizon: A mix of Angle and Acro. Smaller inputs will maintain Angle mode, larger inputs will allow the airframe to perform as if in Acro mode, however when reverting back to smaller inputs or releasing cyclic, airframe will self level.

-Baro: Maintain altitude, can be adjusted with throttle to increase or decrease set altitude

-Mag: Maintain current yaw. ie. Nose will stay locked in one direction

-HeadFree: Changes the control of the airframe such that even if the airframe is pointing toward you, pushing up on cyclic will always move the airframe away from you, pushing left will always move it left. ie. You will not need to compensate for airframes current heading.

-HeadAdj: disables and resets current Headfree state in the event you have moved or changed direction and need to reset HeadFree position

-GPS Hold: Locks airframe into current position

-GPS Home: Returns airframe to take off position (does not land for you, only returns to point of take off

*Some flight modes may require additional sensors or other hardware
 

Mohonky

Member
ESC's, Motors and Props

Having decided what sort of airframe you want and a flight controller to match, you need to purchase the power system for your rotors. There are no real hard and fast rules for this except to say that your ESC should be capable of handling the voltage input from the battery and capable of meeting the specific amp draw of your motors.

Most sellers of airframes will usually give you a recommended battery voltage (2S / 3S / 4S and so on) and recommendations on motor and prop size.

Manufacturers of ESC's and motors are pretty good these days and it's rare to hear of brands offering vastly inferior or problematic products of either so don't be too hung up on branding.


ESC: Electronic Speed Controllers

Generally, you want to ensure that each ESC is capable of delivering the required current demanded by your motors and able to handle the voltage you plan to use.

For a period ESC's flashed with SimonK firmware were all the race, however this has changed and the current flavour of the month is to use BLHeli, particularly for FPV Racers and sports flyers. Faster refresh rates, response times and features like active dampening means BLheli coded ESC's give a very precise, quick response time and currently many of the software forks available (Cleanflight, BetaFlight, RaceFlight, LibrePilot etc) are designed around BLHeli equipped ESC's.

Motors

I had hoped to give you something more definitive on motors however this one can be a little tricky.

The problem here is that there is no 'cohesion' between motor manufacturers when providing the specifications for their motor; because of this when looking at the specification of motors you've never quite guaranteed to be comparing exactly the same thing.

Generally however if you can pull up the specifications on the motor can (physical dimensions of the motor) the larger the motor the more powerful it should be. This again though is only a general guide and not a rule.

The only rule that is relatively consistent is the motor kV.

The kV of a motor refers to the rotations per minute of the motor @ 1 volt. An example of this might be a motor with a rating of 1000kv. The equation to work out the maximum RPM of this motor would be as follows;

V x kV = RPM
7.4v x 2000kv = 14,800rpm.

Or, as another example;

14.8v x 888kv = 13,142rpm

This gives you an idea of the maximum RPM at a given voltage with no load. Once we add the propellers, we can expect this number to drop as the increased torque requirement to spin a propeller and maintain lift will lower our motors ability to hit peak rpm. Increased propeller size and pitch (propeller angle) will incur greater RPM loss, however this will be compensated for by the additional lift of the propeller size and pitch so while you may loss more RPM, you won't necessarily require it as the propellers lifting properties make up for that loss.

Larger, more powerful motors will incur less RPM than smaller less powerful ones but generally speaking because each airframe will use a relatively similar sized motor physically, the kV of one motor to the next should be a fairly good gauge into how much thrust will be achieved.

When choosing a motor, it is best to consider what battery voltage you will be using as, looking back on our equation, moving from a 2S (7.4v battery) to a 3S (11.1v battery) will change our final RPM. So if you are planning to use a higher voltage battery, you may consider going to a lower kV motor.


Propellers (Props)

When choosing props you need to consider 3 main factors; which motor you will be using, is there a limitation on prop size for my airframe and what sort of flying will I be doing?

Here, you're general rule of thumb is that smaller props that offer less lift but higher rpm will benefit acrobatic flight. Why? Because the motor doesn't have to work as hard when adjusting rpm. This allows the motor to alter rpm more quickly giving you superior more a more responsive feel.

Regarding airframe compatibility, due to the shape of some airframes, you may find there is a physical limit to the diameter of the prop. In this limitation, motor and battery choice may be a work around rather than adjusting prop size.

There is an equation commonly used to determine how much thrust is required to get your airframe off the ground;

(Weight x 2) divide by number of motors.

This will give us the required thrust per motor that we need to fly. An example for a quadcopter;

(1500g x 2) / 4 = 750g

So in essence, we need to ensure that our motor / prop selection is capable of 750g of thrust per motor. This would be for our Quadcopter, but if we built a Hexa? Well that's 6 motors, so all we do is adjust our division;

(1500 x 2 ) / 6 = 500g

Each motor now only needs 500g per motor. So we can see the benefit of our Hexa. We could go with motor / props that produce less thrust, or we could stick with something that produced 750g and in doing so we can increase our payload capacity should we want to add anything later.

So, how much thrust will our motor and prop combo's make? We'll that's that big question. Some manufacturers provide charts that give the thrust output of each motor + prop combination, some will even factor in battery voltage also. The problem is many manufacturers in my searches did not and I was unable to find a real definitive guide to provide.

As such, I'm going to provide two links here to two excellent guides for Motor & Prop explanations. Otherwise, a google search of your airframe or the weight of your airframe and motor / prop recommendations can often yield feedback and recommendations from other multirotor enthusiasts out there, particularly on www.rcgroups.com. If you are reading this thread, it's likely worth making an account on those boards as this is the biggest and most knowledgeable board out there and there is a forum for virtually all facets of aerial RC's and components.

Otherwise, check these two links here for a good read / view of Motor & Prop combinations;

http://blog.oscarliang.net/how-to-choose-motor-and-propeller-for-quadcopter/
https://www.youtube.com/watch?t=305&v=HSQGI6u2DlM (I got to watching a few of this guys videos and they were quite good, I will be adding his channel to the Links section)

Batteries

Gone are the days of the nimh and nicd batteries of yore in RC, now, it's all about the LiPo (lithium-polymer). These get a bit of a bad wrap with people suggesting they are extremely volatile batteries waiting to go up at a moments notice; but fear not, with some common sense and general understanding of this technology there is no reason to believe these are any more a problem than any other battery technology out there.

Lipo batteries are made up of individual lithium polymer cells wired either in parallel or series. Each 'cell' within a battery should be 3.7v nominal and reach 4.2v when fully charged. No manufacturer attempts to produce cells of low quality but due to the nature of battery production some cells are better than others. Cells are graded and matched with similarly performing cells to make up a single battery pack. All battery packs sold will have a few important numbers on them that help you select the correct pack for your RC.

While all packs have their own unique branding and flashy graphics, they all have 3 numbers relevant to their performance;

- Voltage
- C rating
- mAh

24676661-origpic-9d5647_zpsnov5ky4g.jpg


On this particularly battery the mAh, voltage and C rating are clearly visible, however there can be some alterations to this. Rather than seeing 11.1v you may see a number followed by S. ie. 2S, 3S, 4S and so on. This is the number of cells in the battery wired in series. Connecting cells (and / or batteries) in series will increase your voltage. In this case, the pictured battery indicates 11.1v, but other manufacturers may label their battery 3S (3 x 3,7v = 11.1v). Either marking is acceptable and ultimately means the same thing.

The C rating of this battery is 30C. This is where one battery isn't necessarily the same as other batteries. C rating is the current handling property of the battery, the higher the C rating, the more power the battery can comfortably discharge to provide either constant or short bursts of power. Typically, battery manufacturers will provide you with the constant and burst rating. In this instance you have a 30C rating giving us only one figure, so it would be fair to assume this should be the constant rating and in many cases it will be. It doesn't mean 30C is the exact output you will achieve, just that it should be the minimum expected. Though don't think that just because that's the minimum you could get lucky and it's actually much higher, it usually means 30C is the minimum, a little more might be possible but it's usually around that mark.

Batteries in the RC world are the equivalent of amplifiers in hifi; there's no real standard means of methodology in how they tested the cells which means one brands 30C could be another brands 25C or even 35C, so don't treat this as absolute, it's more a guide. On the flip side of this, you also have battery manufacturers claiming anything up to 150C but not denoting whether this is a constant or burst rating. You can pretty well guarantee this rating is not a constant as you will find that generally the highest performance packs from reputable brands usually top out at 60-70C max, with bursts anywhere up to 140C.

For what we are doing here, the upper end of the C rating range, 60-70C isn't likely to be necessary, these are usually used for very high amp draw applications like boats, some helicopters or in racing classes of on-road and off-road to make sure they can get the most power out of their vehicle as possible. Having some headroom isn't a bad thing but there's no need to buy the most powerful battery out there if you won't use even a third of it's performance.

To work out how much performance you need from you're battery, you can use this equation;

(C x mAh) / 1000 = Continous discharge capability.

or you could convert the mAh unit to A and not divide by 1000. ie. 2000mAh = 2A

C x A = Continous discharge capability

Using the pictured battery it would look like this;

30C x 1amp = 30amp

You of course need to keep in mind that because we are talking multirotors here, you need to divide that number by the number of motors on the airframe as they will all be feeding off that one battery.

There are 2 ways we can increase our discharge capability and that is to increase either our C rating or our mAh (capacity). If we go for a higher performance pack, we could step up to 40C or 50C, which would give us 40amp or 50amp respectively. If each our motors is capable of drawing 6A constant, then our batteries only need to provide 24A constant. So theoretically, our 30A battery will work, but a 40 or 50A battery will give us a little headroom so we aren't really needing to constantly push our battery hard.

Alternatively if we increase our mAh to say, 2000mAh, with our 30C rating, we can safely discharge 60A. Be aware though, increasing mAh increases the batteries physical dimensions and weight so we need to make sure it'll fit on our airframe and that we have enough thrust to cater for the extra weight. On the plus side, by increasing our mAh, even though we'll be making the motors have to work harder carrying the extra weight and therefore pulling more amps, we should still have increased our flight time due to the larger capacity.

How to tell when a battery is damaged / reached the end of it's life

Batteries are consumables and so you should expect them to one day give up. As lipos are capable of putting out a rather substantial amount of power, it's important to recognise when one is damaged, no longer functioning as it should or could otherwise become a hazard. You don't want to injure yourself or others or have the battery give out entirely when your airframe is a few hundred feet in the air. So a few things to consider on batteries;

Cell Balance: When full charged, a lipo should be 4.2v per cell. Some cells may deviate from this, but it should be by a very small margin. If for instance you have a 3 cell battery that fully charged reads 4.2 / 4.18 / 4.2, this is acceptable. If that same battery read 4.2 / 4.09 / 4.19 then the cell at 4.09 is likely damaged. If any cell deviates by greater than 0.03v after full charge you should consider the battery to be no longer usable.

Battery Puffing: Some people believe a battery should not puff at all, others will say a little is ok. Personally, I believe a little is ok, when I say a little I mean by the absolute smallest of margins after heavy use. I personally have never seen any brand of battery ever not puff just the tiniest bit after heavy use. So long as the amount the battery puffs is virtually unnoticable and returns to normal after cooling and maintains a level of voltage across all cells within tolerance, it should be fine. If however it puffs during charging, under no stress or otherwise puffs excessively, dispose of it.

Do not leave batteries fully or under charged: Batteries should never be left fully charged or undercharged. When not in use, a lipo battery should be stored at 3.85v per cell. When you purchase a charger, try to get one with a storage charge option to make this easier. Some chargers may charge to 3.8v for storage, this is also acceptable.

Do not deep cycle a lipo: Under no circumstance should you full discharge a lipo. The further you discharge a lipo, the more you increase the chances of damaging it. Ideally you should not go below 3.0v per cell, 2.7v at the absolute max. Because you are flying an airframe, you don't have the option to simply kill the power at a moments notice, so plan ahead and come in for landing while you are still in a safe operating zone.

Charging: Buy a decent charger and always balance charge your batteries and when not in use store them at the appropriate storage voltage. When storing or charging a lipo battery you should always keep them in a lipo sack (fireproof bag). Lipo sacks are cheap and come in a large number of sizes so there's no real reason not to use one.

Transmitter (Tx)

Transmitters are Mode 1 or Mode 2

Mode 1: Throttle and Yaw on right stick, Pitch and Roll on Left

Mode 2: Throttle and Yaw on left stick, Pitch and Roll on Right

Mode 2 has become the de-facto choice. Mode 1 basically only exists for older RC enthusiasts who grew up with this configuration. Going forward, there is no reason to go with Mode 1 unless it is something you are already used to, you should be going with Mode 2 at this point.

I could list a few good Tx's, Spektrum has always been popular, Futaba at the higher end along with radios like JR and Graupner, but right now, in the opensource world of multirotors there is pretty much only one radio everyone is picking up right now;

frsky-taranis-case_zps0uex28ml.jpg

FrSky Taranis

Put simply, this is an order of magnitude better than any radio anywhere near it for price and performance. To get anywhere near the same performance and features you would have to spend 3 to 4 times as much as the price of the Taranis and even then, you probably wouldn't be able to match all the features available on the Taranis.

This radio is compatible with a number of other receivers from other manufacturers like Futaba and HiTech but you are more than likely to stick with the FrSky modules as they are cheap but powerful units and offer a large range of options from standard PWM signals to PPM, C-PPM and S.Bus as well as full telemtetry (may require optional sensors).

Like most things multirotor the Taranis is opensource and so it's features and capabilities are not static. It is in constant evolution with improvement to current features and the implementation of new features added frequently. From full telemetry, voice feedback, programmable alarms, low latency signal, channel hopping frequencies, infinite mixes, 16 channels out of the box with the ability to expand to 32 etc. it would be easier to list the things it doesn't do.

So why so cheap?

Firstly, it doesn't have that nice feel of a high end radio. It is a cheap radio and it feels it. That's not to say it feels bad, it is lightweight and ergonomically fine, but the plastics feel hard and it lacks the soft rubber contoured grips found on more expensive radios. This is mostly a small whinge though, because the radio I am comparing it too costs 3x the price and while it certainly feels nice, it actually isn't capable of as much as the Taranis.

Now, back to that opensource nature. Being opensource makes this an incredibly feature rich and powerful radio, no licenses to pay and a software back end largely supported and updated by the RC community. This of course makes it very powerful, but newcomers may be intimidated by just how 'open' this tx is. Where other radios lock you into certain pre-programmed templates the Taranis is a completely blank slate that lets users have complete control over their radio. If you can think of something you would like to program into a radio, chances are you can do it. This isn't a knock against the radio itself, but worth mentioning as this open nature maybe a double edge sword.

Thankfully the programming required for a multirotor isn't all that difficult. You need only assign channels 1-4 for Throttle, Yaw, Pitch & Roll, channels 5-8 you can assign your dip switch positions for flight modes and lastly set your end points on channels 1-4 to ensure your flight controller is receiving the correct low / center / high stick positions.

If you ever need more functions like extra flight mode toggles, custom functions or gimbal control you can switch the radio over to PPM or S.Bus to unlock all 16 channels. If somehow you need more than that (I can't even imagine what) you can add your expansion module and get all 32 channels. Those of you out there with any programming or code knowledge will likely come to grips with this radio rather quickly, for those of us more....normal people, it maybe tricky initially and you may find yourself on rcgroups.com looking for help, but for your basic multirotor needs you shouldn't have much drama getting your multirotor in the air. I actually found it easier than my Futaba 14SG for multirotors. For Helicopters? That's a different story.

So putting aside the fact it doesn't 'feel' as nice as radios considerably more expensive and that for more advanced functions this radio can take a bit to get yours head around, in terms of cost, build, function and reliability (signal range and security, obviously important when your airframe is off in the air) the Taranis is in a league of it's own.
 

Mohonky

Member
Learning to Fly

Ok, so we've discussed multirotors and the components that are used to make one and now, it's time to get that airframe in the air.

This information is relevant to anyone with a multirotor starting out and in truth, some of it will initially sound a little backward and maybe elitist but it'll made sense soon. It doesn't matter if this is a toy, an RTF (ready to fly) like a Phantom or something you have built yourself. The steps are all the same.

First things first: you're going to crash. Accept it. There's generally a mentality between RC owners that is fairly commonly shared; if you can't afford to smash it, you can't afford to fly it. Everyone crashes at some point, whether you're a beginner or a veteran. If you think you'll be the first or last person to do the walk of shame to go out and fetch the mangled mess of something that used to fly, you're mistaken. It happens to us all but we can at least minimise the chances of this happening so that it doesn't hurt our back pocket, but more importantly also to ensure that we don't hurt ourselves, others or cause any damage to other peoples property. Multirotors are getting very popular and there are no shortage of videos and stories on the internet of people flying their airframe in a manner that is both wreckless and dangerous. As the pilot it is your responsibility to ensure the safety of yourself and others. Be responsible, fly only in large open areas and within line of sight. If you can't see your airframe, you are not in control of it.

This is why the very first piece of advice anyone can offer is to go out and buy a cheap airframe. While a $40 multirotor might seem like a toy, keeping one in the air requires the same skills and inputs as any other multirotor but at a fraction of the cost. Smashing or maybe even just losing a $40 multirotor is going to sting a lot less than something costing considerably more. You also have another added bonus here; the smaller the multirotor the more responsive and twitchy it will be making it harder to hover smoothly and orientate. If you can teach yourself to pilot one of these things smoothly, larger airframes will feel infinitely more stable and easier to manage. That's not to say if you can pilot a toy multirotor you'll jump straight behind the sticks of a larger more expensive frame and be a complete Top Gun at it, just that it'll make the transition easier.

Now before we even get our multirotor in the air here comes the contradicting part; if your multirotor has any automated flight modes, turn them off. Yes, if your multirotor or flight controller has any form of automation (GPS Hold, Loiter, Altitude Hold, HeadFree etc) turn it off. This part might come across as a little elitist, and those that learn't to fly RTF's might think I'm taking a stab at them here, particularly as frames like the Phantom are sold on the idea that anyone can buy one and get in the air with little to no flying time or experience; but there is good reason for this. By leaving any automated features of the flight controller on, you have surrendered control of your airframe to the flight controller and the sensors it relies on for feedback. By surrendering control of your airframe to the flight controller you are never actually learning to fly it, you are only making suggestions to the flight controller and it is deciding whether that is within it's parameters. If any of the sensors fail, suffer interference, lose signal (things like GPS units rely on multiple satellite feeds and can lose signal just by variances in cloud cover) or even suffer something as simple as a software glitch the flight controller can become confused and behave in erratic or unexpected ways. This can lead to total loss of control of the airframe causing crashes or the good old 'fly away'. There are plenty of stories of people going out with their multirotor and coming home with nothing but a controller in their hand, some losing not only their airframe but any video devices that happen to be going along for the ride at the same time. Some people get their gear back and upload the video and it can be quite remarkable to see from the multirotors perspective as it calmly flys off into the wild blue yonder, but I'm sure it doesn't quite compare to the sick feeling in your gut of watching a few hundred maybe thousands of dollars worth of equipment just sail away.

I might sound like I'm being unfair here, maybe even bit of a prick, but trust me on this, you want to learn how to fly first. At the very least if you can do the basics, if you choose to fly automated later, if something goes wrong you can attempt to retake control of your multirotor from the flight controller and bring the airframe back so you can go over and analyse what went wrong. This is the other reason you should never fly outside of your line of sight. In the event of something going wrong, you should always be able to turn off all non-essential flight modes and manually pilot the airframe back to a safe landing. I've seen these things happen first hand, it does happen. I know people who've lost airframes or had their airframe behave oddly and crash for no apparent reason. Learning to fly in a manual mode is a must learn skill for anyone who attempts to get a multirotor in the air; the only exception here is Stable or Angle modes. As these simply use the Gyro and Accelerometer, it is perfectly acceptable to use these self levelling modes. Some people may never turn these off or at least use Horizon over Acro. Horizon is probably the best flight control mode bar none as it allows full control while still offering self levelling giving you the best of both worlds.

OK enough harping, lets get to the flying bit.

Perform all preflight checks (props tight, correct direction, motors spinning correct direction, perform preflight flight control calibration etc) before attempting to take off.

We should also be in a large open area free of people and any objects to hit. We want to give ourselves plenty of room for error here. The only exception is with toy multirotors which you may need to fly indoors because they can't handle any breeze or current. Anything 250 or larger, take it out to the park or a field.

Landing

Yeh we're gonna learn to land first. Odd huh? Well if something goes wrong or you freak out, you want your airframe back on the ground as fast and smoothly as possible.

At this point you should be standing behind the airframe, aka tail in.

Slowly power up the throttle until the airframe lifts off the ground. Once it begins to climb you're going to get your first shock if you've never flown a multirotor or helicopter before; drift. Helicopters and multirotors don't move up and down in a linear fasion, they drift around, and they do it a lot. You will constantly be moving the cyclic adjusting roll and pitch to keep the airframe on the one spot. Don't make hard or drastic adjustments; small and smooth.

We only need to get a few feet in the air. Once there, slowly back off the throttle till the airframe slowly descends. You will notice that at a point roughly a foot off the ground or lower, the airframe will 'bounce' back up but because we haven't gotten back on the power, it'll fall and again try to bounce back up so on and so forth until we either give it enough power to ascend or really get off the power so it lands. This is why we're learning to land first. As the airframe gets closer to the ground, you'll learn to find the height at which the airframe will 'bounce;' when it does, compensate by lowering the throttle even more. You'll soon learn to feel where this bounce occurs and how much you need to lower the throttle to prevent it from occurring. It just takes practice. It will become second nature eventually, but for the time being, it's simply about finding that sweet spot of throttle control and knowing when to cut the throttle to prevent it happening. You want to be able to be comfortable with this because once we start moving to actually flying around, you may need to get the airframe out of the air as fast as possible in case something goes wrong or you feel you're really losing control.

Hovering

We should still be tail in. At no point will we be touching yaw control unless we absolutely have to to keep the tail facing us. The reason for this is that while the airframe is tail in, up on cyclic is forward, down is backward, left is left and right is right. If we start changing the direction the airframe is facing that all changes and quickly becomes confusing. So until you master tail in, do not change the orientation.

Now that you can land with some confidence, it's time to try and keep the airframe in the air. Hovering is the most important skill you can learn. It is the most basic skill that all others derive from and will be used as our emergency backup if we feel like we're losing control of our airframe.

Throttle up the airframe until in the air. You don't need to power off into the sunset, anywhere between 7-10ft high is fine. Despite the fact we maybe in stabilise / self level mode, the airframe is going to drift. This is normal, it will always happen. The goal here is to just keep the airframe in the same spot. Imagine there is a small bubble in the air and you have to keep the airframe in it. You'll find that at no point will you not be making movements on the throttle, the cyclic or likely both.

You'll notice for every adjustment you make to pitch or roll one way, you need to compensate the other. Once the airframe gains momentum in one direction, it doesn't simply 'stop' moving in that direction when you stop pushing in that direction, it will continue in that direction until you compensate for it and that's why learning to hover is very important. It will teach you how the airframe responds to input and how much will be required to compensate for drift or altitude changes.

Continue doing this while landing every now and again just to get a good feel for the airframe.

Hovering may take a little while to get used to. You might spend your first few battery packs learning to get comfortable with it. It may take a few days, it may take a few weeks to get really comfortable with. Everyone is different. The important thing is that you should be really comfortable with it. It should become second nature. If all else fails, it should be the one thing we can do without even needing to think about.

Do not move on from learning to hover until you are 100% comfortable.

Orientation

Ok so you can take off, control your airframe in a hover and land. Now, it gets a little tricky. Start tail in. Take off until you are at a comfortable hover. Use yaw to turn the airframe 90 degrees either left or right.

If you have turned counter clockwise (yaw left); you'll find you now have to get your head around the idea that cyclic forward is now left, down is right, left brings the airframe closer to you and right moves it away. In moving the airframe 90 degrees, we've done the same with the controls.

This makes controlling the airframe trickier than it sounds and you may find yourself attempting to make adjustments to the drift of the airframe and actually making it worse as you accidentally push the wrong direction on the cyclic. At this point, it becomes really easy to panic and start really leaning on the cyclic stick making large or aggressive movements. Try not to panic. If things get out of shape or you lose orientation, yaw back into a tail in position and try to regain hover. This is why we need to be 100% comfortable with the tail in hover; it's the most basic skill and should it ever seem we have lost control of our airframe, bringing it back to an orientation and position we are comfortable with can really pull you out of tight spots.

Like the hover, stick with this exercise until you are comfortable with it. When you are comfortable in this orientation, yaw in the other direction and become comfortable hovering the airframe in this orientation.

There is no need to be in a rush from moving on from one step to the next, just get comfortable, you'll have plenty of time to crash later. Once you are comfortable hovering
at a 90 degree orientation, try nose in. This is the most difficult usually, back is forward and left is right, again if you get a bit wild or feel like you're losing control, go back to a tail in hover.

Don't worry if you are never as 100% comfortable in orientations outside of tail in. You should be able to hover in different orientations but it may never feel as comfortable as tail in. Many pilots who have flown for years may never come in nose in and find they always come in tail in. Some people can never really get their head around nose in, it's definitely one of the harder things to get your head around to the put you are as comfortable nose in as tail in. Try to get as comfortable as possible but don't be surprised if it never clicks like tail in.

Figure Eights

Ok, you can land, you can hover and you're pretty comfortable with orientation, time to combine those skills.

Try and fly in a figure 8 in front of you. You can do this making larger radius turns, that's fine. You'll notice that by doing a figure 8, you are performing the full range of orientations of the craft. Try doing it in one direction, then the other.

Do this for a little while and if you can do this comfortably, you'll pretty much be ready to go out and start flying free as a bird and be able to take some comfort in knowing that even if you choose to use more automated flight modes of the flight controller, should anything ever go wrong, you have the skills to fall back on to take back control of the airframe and rescue the situation.

---------------------------------------------------------------------------------

Ok probably fairly done for the moment. I'll add some links in a bit, but for the moment that it a decent start. I'll add some FPV and other stuff later. I would rather see if the thread takes off first (pun wasn't intended but there it is).
 

Mohonky

Member
Are you gonna write about fpv races and how to set up for those ?(equipment etc) they seem really cool

Not specifically, I'm giving a larger overview of multirotors, flight controllers, learning to fly, what accessories you will need or want etc.

However in saying that, at the moment that's just for the introduction to this OT, if you have any specific questions or are looking for recommendations, this is the thread to ask.

I'm tired and my head is spinning so I'll probably goto bed soon but did you have any specifics about what you wanted to know about FPV racers?
 

Mohonky

Member
I'm interested in these things. Will follow this thread.



wjANVCD.jpg

Didn't even catch that when I typed it. lol.

Are you gonna write about fpv races and how to set up for those ?(equipment etc) they seem really cool

If you want to get into FPV, what you really want to look at is a 250 size airframe. Components you'll need;

250 size airframe
Flight Controller - OpenPilot CC3D or Naze32 or a basic Multiwii board like the Paris Air v2
ESC x 4 - These won't need a big ESC, 12-16amp max is all you'd need.
Motors - usually when picking a frame you'll get a recommendation on which motors suit, failing that a google of your frame and motor recommendations. rcgroups.com which is a fantastic resource for very specific questions.
Props to suit motor KV and frame.
FPV Gear: this one depends on your budget.
Radio: I'll be getting into that in the OT.

Many of the frames I've seen seem to be sitting around $150. One of my recommendation on RC stores, particularly for aerial DIY stuff, is Hobbyking.com. They are central to Hong Kong but have warehouses world wide. You can find a number of good frames there as well as motors, escs, props, FPV gear at really good prices.
 
D

Deleted member 10571

Unconfirmed Member
Things seem to be popping up at more and more festivals and concerts over here as well. I'd get one if I'd only knew what for :D
 
"Things seem to be popping up at more and more festivals and concerts over here as well. I'd get one if I'd only knew what for :D"


Probably for photography, though having one of these flying over crowds of people is idiotic and dangerous at best.
 

Mohonky

Member
Is there a GAF RC thread? I'm a plane and heli guy mostly.

Unfortunately not. The reason I'm making a multirotor thread is due to their popularity and we occasionally get threads pop up asking about them but I dont think too many people know much about them outside of Phantoms, but when they do pop up people like the idea of them, they just seem a bit intimidated by them hence I figured I'd give those interested something to look at.

I personally have a fairly decent range of rc stuff. I used to race 1/8 scale electric buggy and truggy, still have them + a monster truck, trail truck and 1/5 scale short course and have also raced 1/10 touring. Multirotors were my first aerial RC, since then I've picked up a Sea Vixen EDF foamy, an Align Trex 700 DFC Super and recently a mate of mine gave me his Align Trex 450 copy (its a hobbyking but all parts are interchangeable with Align) that is missing the head, so I was thinking I'd add the DFC head to that and smash that learning to fly 3D before I smashed the 700 instead.

I'm a veteran at smashing 3d helis in Phoenix already though, so it shouldnt be hard.


The mate that gave my the 450 has some awesome planes. I couldnt name them off the top of my head, he's got the basic stuff like trainers, fov foamies etc, but he also has a 60cc Decathlon (no idea of what scale) and another stunt flyer of about equal size. He had a Mistang but smashed it, so the 60cc and electronics made their way into the decathlon. He also has 250, 450, 650 and 700 Trex, which is what inspired me to get one in the first place. Planes hanging from the roof of his garage are basically 'retired' from duty, ie. The plane grave yard. He's currently looking into a turbine powered jet, should be exciting to watch. Screw trying to pilot one of them, thats too much money to put in the air for my liking.
 

Azulsky

Member
I have really wanted to build one of these on my own for a while as a multi-month project as something code from mostly the ground up and piece together all the sensor modules.


Need to start outlining a plan and budget. Definitely subbed
 

Mohonky

Member
Sorry this is taking as long as it is guys, I havent checked multirotor stuff for a bit so I'm just relearning some things while fact checking other stuff to make sure the information is as accurate as possible so the guide is as correct as it can be.

Once I hit stuff outside of the technical aspect of things like learning to fly etc it'll come along a lot quicker.


Ipthough if anyone has any questions theres no need to wait for it to be completed, fire away.
 

captive

Joe Six-Pack: posting for the common man
Timely thread.

In the process of building myself a hexacopter. Got 6 turnigy 320kv motors gonna swing 17" blades with a tarot x6 heavy lift frame to lift my Nikon d800.
 

Mohonky

Member
Timely thread.

In the process of building myself a hexacopter. Got 6 turnigy 320kv motors gonna swing 17" blades with a tarot x6 heavy lift frame to lift my Nikon d800.


Them some big ass blades, running 12S? Which flight controller, Naza?
 

captive

Joe Six-Pack: posting for the common man
Them some big ass blades, running 12S? Which flight controller, Naza?

Gonna get the cheapest DJI Naza flight controller. Haven't gotten that far on batteries. That's actually the one component I haven't quite figured out yet. I know which ESCs i'm gonna get, got the motors etc.
 

Mohonky

Member
Gonna get the cheapest DJI Naza flight controller. Haven't gotten that far on batteries. That's actually the one component I haven't quite figured out yet. I know which ESCs i'm gonna get, got the motors etc.
I'm just about to start on batteries. What were you trying to figure out on batteries?
 

alterno69

Banned
Nice, i have been a Phantom user since three years ago or so and i own a Phantom 3 pro. Amazing technology, i'm afraid regulatin is about to get pretty crazy worldwide.
 

captive

Joe Six-Pack: posting for the common man
I'm just about to start on batteries. What were you trying to figure out on batteries?

really, what size batteries I need when configuring weight of the battery, power for the motors + 15-20 minutes flight time while carrying the camera and gimbal.

I've seen a video of a guy using turnigy 390kv motors with 17" blades, copter flew for 95 minutes, granted it wasn't carrying anything and it was a quadcopter specifically designed for low weight.

alterno69 said:
Amazing technology, i'm afraid regulatin is about to get pretty crazy worldwide.
Regulation or banning? If its the former, it shouldn't be that bad and make everyone safer, but if its outright banning, that's not right. Or only allowing "businesses" to fly them. Which would also be bullshit. Especially considering the FAA has approved I think 45 applications for drone businesses out of the hundreds of applications.
 

Mohonky

Member
really, what size batteries I need when configuring weight of the battery, power for the motors + 15-20 minutes flight time while carrying the camera and gimbal.

I've seen a video of a guy using turnigy 390kv motors with 17" blades, copter flew for 95 minutes, granted it wasn't carrying anything and it was a quadcopter specifically designed for low weight.

Regulation or banning? If its the former, it shouldn't be that bad and make everyone safer, but if its outright banning, that's not right.


Just looked those motors up, bit surprised that a 390kv motor only allows a 6S battery. Mind you if you're using big props and 6 motors you probably won't need high RPM, just the ability to maintain it. Low amp usable as well for those motors.
 

Yoritomo

Member
About to finish up my first Racing Quad.

Just a ZMR250 kit I've been putting together with a naze32 controller and taranis transmitter.
 

captive

Joe Six-Pack: posting for the common man
Just looked those motors up, bit surprised that a 390kv motor only allows a 6S battery. Mind you if you're using big props and 6 motors you probably won't need high RPM, just the ability to maintain it. Low amp usable as well for those motors.

yea. Lower RPM with bigger blades provides more lift than smaller blades at higher RPM at the expense of lesser maneuverability and response. But I need stability, not maneuverability.
 

mclem

Member
There's something impressively ballsy about a thread title that identifies what it's talking about and then describes it as an unidentified flying object.
 

Mohonky

Member
There's something impressively ballsy about a thread title that identifies what it's talking about and then describes it as an unidentified flying object.

plenty of people mistake multirotors for UFO's these days, with all their blinding LED's just hovering about, also it's not correct to use the term drone even though that seems to be what many people think of them as so I had to put that in some where :p
 
I was thinking of buying one of these, but I never flew one myself. Should I buy a really cheap one to start? I'd like to use then to take high up photos of monuments and structures.
 

Mohonky

Member
I was thinking of buying one of these, but I never flew one myself. Should I buy a really cheap one to start? I'd like to use then to take high up photos of monuments and structures.

After I've done batteries, I'll be doing radios and then giving a guide on learning how to fly.

For the time being the short answer is yes, buy yourself a cheap toy one before moving up to hobby grade. They should only be anywhere between $30 to $70 depending on which you go with. Get one that uses an actual transmitter, Not one that operates via wifi and connects to your phone or an ipad, you want to get comfortable with the tactile feel of the gimbals.
 

Mohonky

Member
About to finish up my first Racing Quad.

Just a ZMR250 kit I've been putting together with a naze32 controller and taranis transmitter.

Let us know how it goes, I'm thinkking of throwing together a cheap 250 quad together, but I have a 350 size I never really got in the air because the motor selection on offer at the time was a few hundred kv down on what I really needed. So now I've figured screw it and I'm going to run it on 4S instead of 3S. That really got it in the air :/

Havent been out flying ages though so I need to tinker with it again, get it all air worthy, tune the PID's a bit and see how it flies. I have a funny. Feeling that running with the 4S, even though it made the back heavy and I had to add weight to the front to compensate, might still put it in the stupidly quick department, just not sure about manueverability.

I also have to get my Scarab Reconn going again, have since added a gimbal but again since i havent been out its just sort of been sitting mostly rebuilt. Thinking I'll finish it up and go back to getting it in the air as well.

Its been about a year since I have flown anything, writing this thread makes me want to get out again.....
 
I was thinking of buying one of these, but I never flew one myself. Should I buy a really cheap one to start? I'd like to use then to take high up photos of monuments and structures.
I'd take a look at horizon hobby products. They cost more than some of their competitors but parts for HH products are usually readily available at most shops and they have outstanding customer service.
 

Mohonky

Member
I'd take a look at horizon hobby products. They cost more than some of their competitors but parts for HH products are usually readily available at most shops and they have outstanding customer service.
Yeh HorizonHobby are a big distributor in the US.

You could also try Hobbyking.com, I have probably mentioned them before, but lots of people buy from there and they have warehouses all over the globe.

Their line up of ready to fly and almost ready to fly;

http://hobbyking.com/hobbyking/store/__592__501__Multi_Rotors_Parts-RTF_PNF_ARF.html

Also, here's some fun videos, everyone loves a fail video;

https://www.youtube.com/watch?v=LkpegCf44AY


This one is one of my favourites, think you know how to fly? You ain't seen nothing..... (ok it's a Trex 700 Heli, but fuck me, prepare to have your mind blown.......also I would be standing behind bullet proof glass, but that's just me, I like my limbs where they are.)
https://www.youtube.com/watch?v=bA3wp9h3abI
 

Yoritomo

Member
Let us know how it goes, I'm thinkking of throwing together a cheap 250 quad together, but I have a 350 size I never really got in the air because the motor selection on offer at the time was a few hundred kv down on what I really needed. So now I've figured screw it and I'm going to run it on 4S instead of 3S. That really got it in the air :/

Havent been out flying ages though so I need to tinker with it again, get it all air worthy, tune the PID's a bit and see how it flies. I have a funny. Feeling that running with the 4S, even though it made the back heavy and I had to add weight to the front to compensate, might still put it in the stupidly quick department, just not sure about manueverability.

I also have to get my Scarab Reconn going again, have since added a gimbal but again since i havent been out its just sort of been sitting mostly rebuilt. Thinking I'll finish it up and go back to getting it in the air as well.

Its been about a year since I have flown anything, writing this thread makes me want to get out again.....

I got it up in the air for the first time yesterday. It was my first build. You can find the kit at fpvmodel (zmr250 v2) which came with a really nice PDB that seems to be a clone of the overcraft zmr250 pdb.

I'm amazed at how much information is already out there to help a newb out when doing something like this, but at the same time the learning curve to properly execute a first build starts out with a big ole bump.

I really should be doing a writeup.
 

Mohonky

Member
I got it up in the air for the first time yesterday. It was my first build. You can find the kit at fpvmodel (zmr250 v2) which came with a really nice PDB that seems to be a clone of the overcraft zmr250 pdb.

I'm amazed at how much information is already out there to help a newb out when doing something like this, but at the same time the learning curve to properly execute a first build starts out with a big ole bump.

I really should be doing a writeup.


Yeh there is lots of informatio out there, I'm to condense as much of it as possible into this thread but because of flight control boards etc, it's impossible to get into some of the specifics.

just about to finish up writing the flying piece, I'm up to the point of explaining how to fly now though lol.

Any pics of your finished frame?
 

RyanDG

Member
This one is one of my favourites, think you know how to fly? You ain't seen nothing..... (ok it's a Trex 700 Heli, but fuck me, prepare to have your mind blown.......also I would be standing behind bullet proof glass, but that's just me, I like my limbs where they are.)
https://www.youtube.com/watch?v=bA3wp9h3abI

Jesus christ. I was watching this in full screen and couldn't help but involuntarily flinch lol.


With that said - just to echo some advice in the information in this thread...

If you are thinking about picking up the hobby, definitely make sure you spend some time with some 'toys' before you jump into more expensive set ups. This past weekend I saw a new pilot who had way too much money to burn send a quad with a GoPro straight into a building at near top speed after he panicked after a system failure that he could have adjusted for and brought it down safely had he kept his head.

Plus, after you are done with the cheaper model, you won't feel half bad about scavenging its guts to sacrifice to other projects.
 

Mohonky

Member
If you are thinking about picking up the hobby, definitely make sure you spend some time with some 'toys' before you jump into more expensive set ups. This past weekend I saw a new pilot who had way too much money to burn send a quad with a GoPro straight into a building at near top speed after he panicked after a system failure that he could have adjusted for and brought it down safely had he kept his head.

Pfft, he should have read my flying tutorial, I finished it all 5minutes ago.

I've been doing some youtubing of quad fails, sooooo many into the side of buildings and cliffs lol.

My other favourites are predatory bird attacks haha.
 

Yoritomo

Member
Yeah. I have a Nano QX that I use for practice.

It's light enough that flying into things won't really damage it, but I've found the range to be super short.

I'd suggest it over the cheaper hubsan x4 mainly because it allows you to fly it in rate/acro mode
 

Mohonky

Member
Yeah. I have a Nano QX that I use for practice.

It's light enough that flying into things won't really damage it, but I've found the range to be super short.

I'd suggest it over the cheaper hubsan x4 mainly because it allows you to fly it in rate/acro mode

Mate did you have any pics of your finished ZMR250?
 

offtopic

He measures in centimeters
Yeah. I have a Nano QX that I use for practice.

It's light enough that flying into things won't really damage it, but I've found the range to be super short.

I'd suggest it over the cheaper hubsan x4 mainly because it allows you to fly it in rate/acro mode

Been interested in these for a bit so picked up a Nano QX 3D this week to both learn and test the water to see if it is something I'd enjoy on a more serious level. So, wow...they are a lot harder to fly than I thought. I'm getting the hang of it slowly but it is super easy to freak out and slam something the wrong way. I have no idea how someone would jump straight to an expensive model without lots of tears and swearing along the way.

Anyways, it is a lot of fun but the manual is pretty skimpy so I'm not really sure what is even meant by rate/acro. It doesn't really explain the differences in modes very well but I'll figure it out as I go.
 

Mook1e

Member
I'm pretty sure I'm going to purchase this RTF kit:

http://hobbyking.com/hobbyking/stor...ter_w_Mode_2_Devo_7_Battery_Charger_RTF_.html
https://www.youtube.com/watch?v=sgHiW524lzo

There are lots of positive reviews.

I'm thinking of getting one for my son as well, but I want to get him something intermediate before he jumps to the big boys.

He's flown a Heli-Max 1sq Vcam for about a year

http://www.helimaxrc.com/helicopters/hmxe0836-1sqvcam/
https://www.youtube.com/watch?v=nxH3tPoZFYw

and I got him an Eachine H8 mini

http://www.tmart.com/JJRC-H8-H8C-Mi...e-RC-Quadcopter-Mode-2-RTF-Black_p326035.html

https://www.youtube.com/watch?v=G5GUYFBXwaM
 

Mohonky

Member
I'm pretty sure I'm going to purchase this RTF kit:

http://hobbyking.com/hobbyking/stor...ter_w_Mode_2_Devo_7_Battery_Charger_RTF_.html
https://www.youtube.com/watch?v=sgHiW524lzo

There are lots of positive reviews.

I'm thinking of getting one for my son as well, but I want to get him something intermediate before he jumps to the big boys.

He's flown a Heli-Max 1sq Vcam for about a year

http://www.helimaxrc.com/helicopters/hmxe0836-1sqvcam/
https://www.youtube.com/watch?v=nxH3tPoZFYw

and I got him an Eachine H8 mini

http://www.tmart.com/JJRC-H8-H8C-Mi...e-RC-Quadcopter-Mode-2-RTF-Black_p326035.html

https://www.youtube.com/watch?v=G5GUYFBXwaM

That Walkera looks like a good bit of kit, I like that they dont use a direct wire back to the battery but detachable, god that would save some time hooking up instead of making wiring looms. Good idea that. Its Walkeras flight controller I presume?

The OsD is good, saw it giving pitch and roll feedback in degrees, useful to telling if accidently going away or toward yourself in high wind, I know thats caught me off guard in high wind before lol.
 

Mook1e

Member
That Walkera looks like a good bit of kit, I like that they dont use a direct wire back to the battery but detachable, god that would save some time hooking up instead of making wiring looms. Good idea that. Its Walkeras flight controller I presume?

The OsD is good, saw it giving pitch and roll feedback in degrees, useful to telling if accidently going away or toward yourself in high wind, I know thats caught me off guard in high wind before lol.

Yeah, the controller is the Devo 7.
I did have a question as well. If I get a JJRC V686 FPV, would I be able to use the controller for any of my son's quads? Would I be able to get the Walkera copter only and use the controller?
 

Mohonky

Member
Yeah, the controller is the Devo 7.
I did have a question as well. If I get a JJRC V686 FPV, would I be able to use the controller for any of my son's quads? Would I be able to get the Walkera copter only and use the controller?


You can but not straight out of the box, you'll have to swap over the receiver (rx) to something the transmitter (tx) understands. They all speak their own sort of language and I'm not sure what protocol Walkera use. Most RTF's werent really designed with swapping out components and the JJRC V686 looks kind of small so you'll have to see what RX is compatible with the Devo 7 transmitter and then whether that RX will sit in the frame of the V686, failing that you could always stick if to the underside of the V686 but anyway you put it on, you may upset the balance of the quad, those RTF's are kind of designed as an all in one so being able to customise or change out certain parts may or may not be possible and adding or subtracting weight is going to mean you maye need to adjust the PID's setting in the flight controller which may or may not be possible depending on what it is.

I would probably just leave those RTF plastic bodies alone and use the included controller.

The Walkera 250 fpv you linked is different in that its an RTF but its basically just a prepackaged hobby grade piece of kit. With those sort of frames you can tend to interchange components no problem and they are designed to be pretty modular, so the 250 wouldnt have a problem if in the future say, you changed over to another tx, you just buy compatible receivers and swap them over.
 

Mook1e

Member
You can but not straight out of the box, you'll have to swap over the receiver (rx) to something the transmitter (tx) understands. They all speak their own sort of language and I'm not sure what protocol Walkera use. Most RTF's werent really designed with swapping out components and the JJRC V686 looks kind of small so you'll have to see what RX is compatible with the Devo 7 transmitter and then whether that RX will sit in the frame of the V686, failing that you could always stick if to the underside of the V686 but anyway you put it on, you may upset the balance of the quad, those RTF's are kind of designed as an all in one so being able to customise or change out certain parts may or may not be possible and adding or subtracting weight is going to mean you maye need to adjust the PID's setting in the flight controller which may or may not be possible depending on what it is.

I would probably just leave those RTF plastic bodies alone and use the included controller.

The Walkera 250 fpv you linked is different in that its an RTF but its basically just a prepackaged hobby grade piece of kit. With those sort of frames you can tend to interchange components no problem and they are designed to be pretty modular, so the 250 wouldnt have a problem if in the future say, you changed over to another tx, you just buy compatible receivers and swap them over.
That's what I figured. I just want to transition my son into the more serious quads well.
I also don't want to go get the Runner 250 for myself while he's stuck with the slower toy grade quads. He's too impressed with the Runner and wants it for his birthday like NOW. :D
I just want him to get something in the middle and I figure the V686 is the closest without spending too much.
 

Mohonky

Member
That's what I figured. I just want to transition my son into the more serious quads well.
I also don't want to go get the Runner 250 for myself while he's stuck with the slower toy grade quads. He's too impressed with the Runner and wants it for his birthday like NOW. :D
I just want him to get something in the middle and I figure the V686 is the closest without spending too much.

How old is your son? Is he capable of flying something like the Runner 250?

Radios are a kind of 'one and done' thing, which is why I didn't really bother mentioning any outisde of the FrSky Taranis. The Taranis is the most powerful and feature rich radio you can buy at any price point. Its opensource nature is what makes it so powerful but it also means you sort of need to program everything into it for each model from a clean slate so it might be a tricky radio initially to get into but you will never need to buy another radio again, you just buy a receiver for each model to bind to your Taranis.

If you are going to get involved in having multiple quads that you build yourself getting a good radio is a one off cost you end up having to eat the firet time out but its one of the pieces you in theory should never have to replace, which is why getting one that can do everything straight off the bat is better in the long run, it's something you'll keep for many years over many models.

The only other components like it are things like battery chargers (get a good one with ample power supply that can do everything up to 6S at a reasonable amperage), FPV goggles, ground stations etc. thats the sort of stuff you want to spend a bit on starting out which does increase the price of entry but will be something you never replace or upgrade for many years.

(i did buy a Futaba 14SG for helicopters because the Taranis is a nightmare for setting up collective pitch helicopters, google a guide to how to set one up and you'll see why, though some people say its easier, it depends on how your brain is wired to see these things I suppose, I know what I need to do but I am a kinaesthetic learner, so seeing it written out might as well be mumbo jumbo to me which is why I use my Taranis for quads and the 14SG for Heli's).
 

Mook1e

Member
He's only 12. That's why I want to get him the in-between flyers first.

I'm not sure he would be able to control the 250 right off the bat, so I want to introduce him to a larger quad with the V686.
 

Mohonky

Member
That's what I figured. I just want to transition my son into the more serious quads well.
I also don't want to go get the Runner 250 for myself while he's stuck with the slower toy grade quads. He's too impressed with the Runner and wants it for his birthday like NOW. :D
I just want him to get something in the middle and I figure the V686 is the closest without spending too much.

If you think you're young fella can handle something like the Runner 250, build something like this;

http://hobbyking.com/hobbyking/stor...Copter_A_Mini_Sized_FPV_Multi_Rotor_kit_.html

http://hobbyking.com/hobbyking/stor...troller_Soldered_version_Horizontal_Pin_.html

http://hobbyking.com/hobbyking/stor...06_2150KV_Motor_The_34_Baby_Beast_34_V2_.html

http://hobbyking.com/hobbyking/store/__58261__Flycolor_10_Amp_Multi_rotor_ESC_2_3S_with_BEC.html

http://hobbyking.com/hobbyking/stor...or_ABS_Propellers_One_Pair_CW_CCW_Black_.html


---------------------------------------------------------------

It might be more expensive but it's modular and it'll be something he can grow with. My mate built basically the same thing for shits and giggles and he just abuses it and it takes it no problem. The downside of something like the V686 is it's plastic chasis. If somerhing breaks, you're kind of screwed unless you know where to get spares. It will cost more but the V686 isn't that much cheaper. If you want him to get a toy to start, check out the $30-$40 models and build this for when he's ready. Hell you will probly fly something like this for fun to learn to do flips and rolls yourself (I know I am thinking about it)

You can add FPV gear later (it's not expensive) and you can use this as an excuse to order a decent radio which you can use yourself later or even with the Runner 250 if you change out the receiver.
 

Mook1e

Member
That does look compelling. I'm going to see how well he handles the eachine H8 mini first, I think. Then I'll make my decision between the V686 and the Walkera.

I'm going to be doing some flying with my own eachine H8 mini in high-rates to decide if I should get something between it and the Walkera myself.

Either way, I look forward to sharing the experience with him.
 
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