Long Range Copter

Building a Long Range Copter

The importants is

1. Weight!
2. Weight!
3. Weight!

No, seriously: It is clear that the copter in fact quasi may be nothing more than a flying battery away, or else nothing with haul flight. Thanks to the now freely available on the market Sony US18650NC1 lipo, or the equivalent thereto by Panasonic, the possibility arises when, for example, a battery weighing around 500 grams compared to the standard LiPo more than double the wattage to hang under the copter.

But: The commonly used in modeling LiPo batteries are designed for high performance, is to say: I want 5-10 minutes to get out the maximum power out of my engine-propeller combination. For a range aircraft of course uninteresting, it is about a maximum capacity in a comparative way low carbon intensity. Here are the new Sony and Panasonic LiPo come into play. They provide with significantly less weight more than twice the performance at Caution !: just 2C!

Side note: What's "C"? This value indicates how much current the LiPo can deliver maximum. The value of C refers to the LiPo capacity.

Example: A LiPo is specified with 3000mAh and 20C. The maximum current is now calculated as follows:

(3000mAh / 1000) x 20C = 60 amps Such LiPo do so before the 60A power.

Ergo, we must ensure that a copter with good 80cm to 1m span can be moved reasonable, although he never more than max. approximately 15-20 ampere rating may be available. And even then this is already more than borderline for the "small" cells.

An exact dimensions of the new battery I go back later separately a ...

Means nothing other than: Preferably below 400kV - and thus end up with an engine size in the 5000 range (5, x cm diameter), which is designed for 17 "propeller.

Well, the boundary conditions are. Since I can not see so slow our hardware store inside umpteen different DIY Copterbauten, we resort to the setup of the proposed Long-Ranger exclusively on Stock Items to - speak to constituents that everyone can order from dealers on the Internet.

A note on prices and weights: These are daily prices and weights of various retailers on the Internet. Whether and to what extent, then shipping and tax are due - if an order gets stuck in customs for example - is not considered here. Also, the details differ to the weight of a component from dealer to dealer, as some specify only the weight of the board, others the weight of the PCB with cables and still others simply just the shipping weight. This is not always easy to figure out what just meant ...

Motors, cost of 4 pieces 55, - €:

These are now found quickly, because here the pros from all over the US and China have already been shown in various YouTube videos, which motor is "apparently" best suited here. Apparently because the experience with it yet significantly diverge. In terms of quality, but also in terms of consumption and scored flight time. This is the 5010-14 360KV Brushless Multicopter Motorvon RCTimer. The engine like 17 "Propeller and offers a direct recording of the propeller without adapter. Because: Now it comes to respect each gram! According to the latest videos on YouTube, we're talking reasonably feasible configuration of at least 70-120 minutes of flight time!

So the engines get 17 × 5.5 Carbon Fiber Propeller, which is also present two holes for direct mounting on the housing. Thus, each engine weighs propeller - and without the then obsolete included adapter - just 104 grams.


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ESCs (cruise control), cost of 4 pieces 40, - €:

Afros from Hobby King. Point. After the experience with my current Copter, I will not say anything else to the moped. Also: HK has thought and offers the new AFRO-ESCs now in a newly revised "Slim version" of. Slimmed down to 20A - which should be enough so easy for us - are the boards much narrower, thanks path optimization heatsink much easier thanks to the design and aerodynamic normal. They are 12mm width even so narrow that the ESCs directly into the carbon-arms (internal diameter 14 mm) can be sunk. The weight per engine increases with these speed controllers are each so just 14 grams.

Base / arms:

Yes, sore subject. Of course you can here with appropriately contemporary interiors in the hobby room design simple carbon plates and -pipes fit and thus provide an ultra-light frame on the legs. But I have neither the desire me to manually beplanen a frame via CAD, nor have I to me still perfect to cut a reasonable water jet cutting in the basement of the whole. Therefore, as I said stock items.

Existing framework (50, - €) tune and rebuild, costs about 25, - €

So I resort to the existing Copter and get back to him with the balance to the body. Only 16 connector in the frames are square, heavy metal connector. The come out and be replaced by Nylonspacer. The two additional small carbon plates - a receiver / flight control holder and a battery base plate - mounted with aluminum rods and metal screws are not replaced. The technique is found in the generous Copterbauch kinda place, as the speed controller so now disappear completely in the arms. The original arms come from and are replaced by new carbon tubes in the same thickness (16mm outer diameter) but replaced each with a length of about 35-38cm. The engine mounts fit for the envisaged engines and lie with 16gr. per holder in a very good cut. In the end, the weight ratio will change as follows:

520 gr. original HK Alien 560 Carbon frame with 50cm range

92 gr. Landing Gear

23 gr. NAZA + receiver bracket and hardware for mounting gimbal

60 gr. Exchange: Carbon fiber booms (arms)

10 gr. Nylon Spacer / mounting / Hardware

=

475 gr.

Total weight after conversion to 80cm wingspan

Thus, the framework is despite the new size definitely in a very good area in terms of the expected total weight.

Electronics / telemetry:

Very important for the project is an absolutely reliable telemetry. So a small excursion thoughts: We must be able to definitely see what consumption, the engines have to date and need a live view of the remaining capacity of the battery. Nothing is likely to be more annoying than that the copter at a distance of 10km decides of nowhere - let alone on a heavily traveled highway - to land because the voltage is insufficient and we were just not informed in the moment.

Although naturally comes to the NAZA flight control iOSD a Mini that already fades some values ​​in the video signal. But unfortunately the iOSD is not to detect the instantaneous power consumption capable of only the remaining battery power. Here it is important to have a fallback in case the video link should be times briefly interrupted and an extension of the display. That is, we use here in addition to the already in the FrSky telemetry Taranis integrated log function back. Thanks to the new development of the X8R FrSky receiver with smart port, we can finally without additional telemetry Hub (weight!) Working on the copter. The Voltage / Amp module is now simply plugged into the receiver and weighs just 17 grams.

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Flight control, cost about 220, - €:

The point can deal with quickly to happiness: The current NAZA of DJI. The small box has proven itself repeatedly and is relatively flexible in configuration and equipment. It must be noted here, however: The NACB Lite provides "out of the box" no port for the iOSD Mini for transmission of telemetry data in the video signal here must in any case, the NACB M V2 are used!

The remote control and the problem with the range ...

As already indicated, the FrSky Taranis come in the future definitely used.



Zig channels, telemetry, data logger, graphic display, modular bay, Speech, OpenTX ... this remote control is definitely the next purchase, especially for such a copter. Now we do not want to continue herumrumfliegen in "a few hundred meters" stubborn in a circle around us, but bring the technology available to their limits, right?

 

The problem of ranges in the 2.4 and 5.8 GHz frequency band. Loosely speaking, the higher the frequency, the crappy range. For example, a radio signal bouncing off obstacles in its environment in a similar angle from what it has impinged on the obstacle - to be destroyed without appreciably. A signal - broadcast with 5.8GHz, however, rather behaves like a raw egg that you throw against a wall: It bursts into 1000 items and drifts relatively uncoordinated on.

Anyone who is a new "DJI Phantom II Ultra Vision anything Plus" bought, can sing a song about it. Changing the transmitter frequency of DJI pages on 5.8GHz band now has the consequence that the expensive crates can no longer be controlled than a stone's throw away. For a "long-range Copter" completely pointless and definitely not the intended target.

Anyone familiar with the Turnigy 9XR or the FrSky Taranis knows that on the back of a module slot is in the quasi-arbitrary transmitter modules can easily be clipped. Then you go into the menu and switch from internal to external and transmits the thing about the future, the inserted module. Here the range from 433 MHz to 5.8 GHz.

We want to in the first attempt only crack the 10km mark, so to say, the video signal and also the radio signal must be rated at least for the range. Now there is the Taranis on 2 ways. It retails for a whopping $ 200 a 433MHz module from the company ImmersionRC (receiver + transmitter combo) and reaches immediately easy reach 20-80km (Caution: In Germany not allowed)



or the antenna of the Taranis is replaced by a sensible WLAN antenna with 9dB power and taking it in the 2.4 GHz band ever +/- 10km.



For the 433MHz module has unfortunately - despite the enormous Range advantage - a decisive disadvantage for us: It sends (yet) telemetry data. And a prerequisite for the project in terms of security was indeed the double protection in the transmission of flight data.

Although the new modules have a USB port for regular updates, but unfortunately I could not ascertain when an update with telemetry function is active.

So we are content for now with a favorable appreciation of Taranis by replacing the standard antenna with a rational. For this, the cost is only 10, - EUR + a 5-minute use of your soldering iron to replace the coaxial cable and the telemetry data continues to be transmitted with.

On the battery:

After the basic structure of the new - and revised framework - and a preliminary sizing of the technical components of the new setup, we come to probably the most important piece of equipment: the "LiPo".

To understand how after the battery has to be sized to achieve 1> = hour flight, a small excursion into the battery Client:

In the conventional available for model batteries there is a standardized assignment of the ports, the results from the pattern of the inner interconnection:



So we have here a "Main Power Connector", against which the total voltage of the cells and single taps, which lead to the so-called balancer.

Each cell of a LiPo has a nominal voltage of 3.7 volts and a charge voltage of 4.22 volts and 4.2V standard.

The use of a LiPo place in a, we call it "voltage window" instead. This is between 3.3 volts and 4.2 volts. If the voltage drops below 3.3 volts in a cell, it will be irreparably damaged.

The picture above shows a so-called 4S battery, there are four cells in a row, and thus increase the rated voltage to 14.8 volts. The capacity does not win in the series connection of course to increase, thus the capacity of individual cells was determined at the same time the total capacity of LiPo batteries.

Back to Long Range Copter. What do we need? So much capacity as possible, at a voltage of "straight time" 11.1 volts because the motors are already satisfied with a 3S battery.

If you buy now in the shop next door a Model Lipo, it is a generally offered something like this:



4000mAh 3S1P 25C at ... huh? So 3S means that hang here 3 batteries in series and thus offer a total voltage of 11.1 volts. 1P is the number of parallel-connected batteries. 4000mAh Lipo is the capacity of what that is, in the overall context means nothing more than that here we have three cells with a capacity of 4 per ampere hours in a row. Shrink wrapped in foil and provided with electricity and balancer.

25C is the maximum current output, which can thus provide a cell - it also changes the series nothing - and thus a maximum load of (4 x 25 =) is 100 amps.

This high power availability is reflected in these batteries unfortunately considerably in weight down. So a battery weighs between 400-500 grams.

Now the conditions come to the envisaged battery for the Long Ranger into play. We do not need 100A amperage and must achieve a much better balance between weight and capacity. Luckily, Sony and Panasonic have a treat for us, which it has done so slowly in the end customer trading thanks to exponentially growing awareness:



Technical Specifications:

Typical cells Voltage: 3.6V

Nominal Capacity: 2900mAh

Final charge voltage: 4.2V

Entladeschlusspannung: 2.5V

Current rating: 8A, 2,75C

Dimensions, weight: 18x65mm, 43g

A look at the technical data makes the heart beat faster Model: cell voltage of 3.6V? Fits. Final charge at 4.2V? Fits. Discharge until ... now it gets interesting: 2.5V compared to 3.3V! This means our power window has just almost doubled! Nominal Capacity 2900mAh at a whopping only 43g per battery cell! The C rate is of course much worse, but even here the picture is improving, we summarize these cells once in an interesting combination for us together:

We need here:

1. 3S, ie 11.1 volts

2. A theoretical maximum load of 4 x 8 amps per motor. For the latest on the selected 10A engines will burn up according to the manufacturer in the firmament.

Here we go: 3 cells in series give 11.1 volts. We are carrying capacity at 8 amps. The whole quadrupling we now in parallel and thus get to our desired 32 amps. 12 cells á 43g now give a total weight of 516g. In addition, there is a capacity of 11600 mAh fabulous.

If we compare the result with a LiPo same weight on the model market:



Quelle: http://www.akkukonfigurator.de/akku-konfigurator_accu-rechner.aspx

The charged battery has a voltage of 12.6 volts. In various YouTube videos can now be seen that a copter with low weight - pulls in the "glide" between 4-7 amps - similar to our previously compiled configuration. This is an extremely good consumption, should be to do with the engines too. Let us now go even pessimistic of 8 amps, which draws our Copter, then this corresponds to about 100 watts. Let us calculate now with this 100 watts from the capacity of 11600mAh a theoretical flight time, we actually come to a little more than 60 minutes of flight time!

Now, not every desire, let alone the technical requirement to consuming to solder the individual cells in the required configuration together. Fortunately, there are now also with us - in the normally living in Europe in caves Model shop operators - the possibility of the desired LiPo ready-made welded and assembled to meet desired to cart:

An example is the "Model fox" in Moers gennant, the newly recognized this trend and offers individual LiPo for sale.

If anyone would like to order for reasons of cost and solder the cells individually:

Tip 1:

Do not be tempted by the offers on Ebay and Amazon! Here are offered for the most part 18650 battery cells whose capacities are beyond good and evil. According to Sony, and Panasonic is at max. 3400mAh per cell circuit. Various disappointed buyers have there decomposed with 6000mAh battery and more specified and except for a little bit powder and a small hidden 700mAh battery found nothing.

Tip 2:

Well, as far as the power supply of the long-range Copters. As far as the FPV flying, this is much more complicated, because the 433/900 MHz to send and 1.2 / 1.3 GHz in Germany is subject terribly complicated rules and laws, so that even hundreds of pages long in various Amatuerfunker forums is dealt with it ...