Getting a helicopter ready for nightflight

This article will tell you how to get a helicopter ready for nightfly with el-wire, do-it-yourself-nightfly-blades and led-stripes...

Table of content:
- Intro
- Leds on fin and canopy
- EL-wire
- Nightblades
- Tips
- Links / Items used

Intro

Have a look at the video and the next picture to see the final result, if you like what you see, continue to read how to achieve it yourself.

Okay, so you liked it? Great - here is how it works:

For my entry into helicopter nightfly I used a cheap HK-450 I had sitting on the shelf for a while now. Just make sure you pick a heli that flies ok and that you are totally comfortable flying by daylight, other than that any will do.

Leds on fin and canopy

I used Turnigy-Led Stripes from Hobbyking. They operate on 12 volt - which means, we can just hook them up to our 3S Main-Lipo. If your heli is bigger and therefore uses a higher voltage main-pack you can just install a separate small 3s lipo to power the leds.

The ledstripes can be cut every 3 leds so you can just measure your tail fin and canopy and cut them to fit. On the canopy you connect the two stripes with a thin cable and then attach a plug (I used a JST plug) so they can be plugged in and out for easy canopy removal.

The female jst connector and another thin cable are soldered to powerlines on our ESC (at the main-powerplug). The thin cable leads to the leds installed on both sides on the tailfin and powers the two stripes there.

The Leds are really cheap, you can get 1 meter of them (which is way more than I used on the heli for around 5$ at Hobbyking).

EL-wire

The el-wire is the glowing cord/wire/string that's spirals along the tail in blue and in orange along the landing gear. El-wire stands for electro luminescent wire. It needs high voltage to light up, but do not fear that's what inverters are for.

The inverter is the black box attached to the side of the heli, it takes in 12 volt and puts out exactly what the el-wire needs. You just have to make sure to buy an inverter that fits the length of the el-wire you install.

In my case that's 1 meter of orange and 1 meter of blue wire, so I bought the inverter that powers 2m to 2.5m of wire.

The wire is not as cheap as the turnigy leds (I paid 8$ per meter and 7$ for the inverter) - but I bought it locally, you might get better prices in Asia.

The hardest part when installing the el-wire is to get the wire hooked up to the inverter (if you buy it without already fitted plugs) because it's really small and you have to pay attention to not cut the small core / leads when removing the isolation.

Nightblades

For the night blades I started out with a normal set of glassfiber blades. - Do not use wooden blades, because those are covered by plastic foil which will not withstand the short bursts of heat that the soldering of the leds will throw at it.

To get current to the leds and also to provide something to solder them onto I used copper tape (which is a very thin tape made from copper with adhesive on one side, you can buy it on ebay for example - people use it to provide the electrics in dollhouses).

My tape was about 6mm wide, so I cut it in half and taped it along the blade with about 3mm distance between the two strands. Near the blade tip I installed two much shorter portions of tape to provide current to the bottom of the blade. Make sure you tape that along the thick edge of the blade.

As close as possible to the blade grip I then taped a 130mah Hobbyking 1S Nanotech lipo, which is secured with a heat shrink (which has to be just big enough to fit over lipo and blade at the same time). Onto the copper-tape there i soldered a connector so that it can be plugged into the lipo. - I also have another long cable with the same connector so I can charge the lipos while they are attached to the blades.

Now comes the tricky part, installing the leds.

I have used smd leds in the 0603-size. They are small, you won't believe how small. If I ever do it again, I will use bigger ones. Not because I need more light/power or anything, but just because those tiny ones handle horribly. (I actually had to get help from a friend who has the equipment to solder such tiny tiny stuff.)

Each led needs its own resistor - you have to calculate the right resistance. For that you need the led forward voltage (see datasheet from the led manufacturer) and you need to know that your lipo has about 4 volt. (Most shops that sell leds have an online calculator so you can check what resistors to buy along with the leds).

After they are soldered on (make sure you take note which of your coppertapes is + and which one is - and to install the leds the right way around!) you can test them by plugging in your lipo.

Before the first test flight there are a few important things to do:

Secure the lipo using the heatshrink.

Secure the leds with epoxy (or maybe superglue), i used epoxy and a toothpick to get it to cover the leds and stick them to the blade. The epoxy forms a blob that has no rough edges, so air should flow well enough over and around it. Also secure the ends of your coppertape the same way, so it can't start peeeling off.

Balance the baldes - I just had to use around 10cm of tesa-tape applied to the center of gravity on the lighter blade to get them even.

(Smudges are from the marker I used to mark the led spots and which color goes where.)

Tips

Make sure there are no loose cables or el-wires that can touch any moving parts.

Test your blades on the ground - or a low hover - with enough distance from your heli that if something / anything flies off you are safe.

Do your first test flights by day after installing everything, so you focus on checking that everything holds.

Get bigger leds than I did, or at least make sure you can solder stuff as small as that.

Maybe get thicker el-wire, I orderd the smallest one 0,9mm - it's a pain to get it connected to the inverter, 0,9mm makes for really tiny core and wires inside it.

Links / Items used