Trex 450 UV-LED Night Flyer

[Augman37]

Awesome job!!

[legobrains]

Did you paint the inside or outside of your canopy?

[SantaMonica]

I painted the outside. Very scratch resistant, too. I did not even sand the plastic first.

[euhero987321]

Woah... thats so cool.. I got to make one myself

[avengedkevinfold]

whats the benefit of using UV LEDs? Seems a pain to have to wear the glasses while flying at night. can I use regular LEDs?

[kavic5150]

Hey again Kevin. I think the OP was using UV to make the paint on his canopy light up. Even blue LED light strings can cause some visual blur. The canopy material and/or the UV reactive paint might block some of the harmful UV light. But why risk it? Its really bad for your eyes.

And something I didnt mention before, white LEDs often have a coating of phosphorous to distribute the light across a more broad spektrum and avoid that bluish tint. In short this causes white LEDs to outshine other colors and should be used sparingly.

[avengedkevinfold]

Thanks for the reply but I still don't understand!
Let me clarify.

From my understanding there are two types of LED lights that we are talking about. UV LEDs and regular LEDs. With UV LEDs apparerently it is suggested to use safety glasses when flying. With regular LEDs you do not. Correct?

With that being said, is it not possible to achive the same glowing canopy effect with the non LEDs with the same paint? What is the benefit of the UV LEDs?

[kavic5150]

I'm no Bill Nye but let me take a stab at this. The UV LEDs will make flourescent paint glow. Kinda like those blacklight posters from the 70s. You could always use other types of LEDs to backlight a translucent canopy but the effect will not be exactly the same.

Ever worn a white T-shirt in a nightclub that has blacklights (UV lamps)? Just no way to recreate that effect that I know of.

As for the UV safety glasses, they are recommended with this type of setup. Even if you managed to clearcoat the canopy with a paint that blocked UV light and only let thru the visible portion, you would still see direct UV light in certain heli orientations. Yes tail in hovering would be the worst.

If you wear glasses, especially with plastic lenses, they probably already have a UV blocking coating. And if your glasses are tinted they are even more likely to have a UV coating. If you want to check how well your glasses block UV, just find a floursecent blacklight lamp (not incandescent, they dont produce alot of UV) and hold your glasses in front of the blacklight. It should appear much darker thru the glasses than otherwise.

Those UV LEDs would only be good for backlighting a canopy with flourescent paint or illuminating other parts of your heli with flourescent materials, paint, stickers, etc, and will not at all compete with the brightness of other LEDs.

Oh, about those KBDD glow in the dark tail blades with the single LED, dont bother. They are barely noticeable even with LED strings on a 2S power supply.

[avengedkevinfold]

Thanks for the response.

What is the wattage of the 100 & 220 ohm resistors that are needed for this build?

I called my electronics store and they tell me that i need to know the wattage. They said they have anywhere from .25 to 25 watt resistors.

[avengedkevinfold]

also, how much EL wire do i need for each side of the skid?

[kavic5150]

El wire drivers usually have 2 output channels each. Are you saying you want different colors for each skidpipe or each landing strut? Either way you will have to plan accordingly or use 2 el-wire drivers.

I dug up an old thread of mine that you might find useful:

https://www.helifreak.com/showthread.php?t=230602

If you use the align el wire driver you might want a separate 2s lipo to power things. I'm thinking 350ma should be fine for 3 flights or more. You can also power some LED light strings with the same lipo if you wanted. They are still fairly bright at 9v but are normally powered by 12v. I think at 9v they will not overpower your el wire.

Since small lipos that size usually have JST plugs I made a 3 way wiring harness with female JST plugs and put male JST plugs on the ends of the LED strings.

And for LED resistor values, just use this: http://led.linear1.org/led.wiz

Usually 1/8 watt resistors are indicated for night blades. The resistor calculator will say either 1/8 or 1/4 watt along with the resistor value in ohms. And be careful when you order smd resistors. Dont order 33k ohms if the resistor calculator says 33 ohms.

[kavic5150]

Heres a quick link for the el wire driver and a single tube:

http://www3.towerhobbies.com/cgi-bin/wti0001p?Q=1&I=LXMPN2&P=3

Remember that el wire is naturally green so that will be the brightest color option. Followed by yellow, blue, purple, orange, red more or less in that order. Other colors are achieved by adding colored dye into the silicone jacket around the el wire itself if I read correctly.

Also these will appear brighter on a 6v system and have a switch on the inverter itself for steady or blink mode.

[SantaMonica]

With UV LEDs apparerently it is suggested to use safety glasses when flying. With regular LEDs you do not. Correct?

Yes, as far as I know.

What is the benefit of the UV LEDs?

They make the canopy glow.

The resisters are 1/2 watts. The skids have about 2 feed of EL each, on them.

[avengedkevinfold]

Hey guys thanks for all your help. Check out my maiden night flight.

[ame]http://vimeo.com/31668276[/ame]

[kaos]

looks great! I like that purplish bottom blades color. top green is not my favorite color though.

[avengedkevinfold]

bottom blades is blue - red - blue stripes. looks purple. cool.
top is green - white - green stripes. didnt turn out very well. anybody have some suggestions for LED color swap on the blades on top?

[kaos]

Looks like your led spacing got some color mixing effect. cool. I wonder if you change out the top middle white to red, would it look like orange/yellow?

[avengedkevinfold]

I found a good light color calculator here.

[kaos]

Originally Posted by avengedkevinfold

I found a good light color calculator here.

good calculator. what is your spacing distance between leds? and are your using 1210 (3528) leds?

[avengedkevinfold]

i dont have the heli w me at work but maybe you can figure it out based on these photos of my 325's