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Darth_Elevator
Dec 19, 2007, 03:22 PM
I replaced the magnet wire in my Slow Stick nightflyer the other night, opting to put in some thin insulated wire for peace of mind. So while I was redoing my lights, I figured I'd try capturing it on video. I hope this will be of some help to anyone thinking about turning one of their planes into a nightflyer. Caveat: this video is not meant to showcase my pathetic soldering technique; please limit your criticism of my soldering abilities to one post per day.

http://www.vimeo.com/442649

Materials Needed
22 LEDs
22 Resistors matched to your LEDs for 12 V power supply
Phone cord
Micro Deans connector (the side with two female connectors solders to the ESC, the side with two male connectors solders to the lights)
Solder
Soldering iron

Weight
The total weight of the light system -- including LEDs, wire, solder, resistors, and plug -- was 0.95 ounces. By way of comparison, the old magnet wire system I replaced was only 0.20 ounces lighter. The weight penalty well worth it, in my opinion, to not have to worry about whether the magnet wire will suddenly and (and maybe violently) short out by getting scraped.

Obligatory Warnings about Soldering Safety
Always practice safe soldering practices. Solder in a well-ventilated area away from flammable materials. Do not touch the soldering tip and NEVER place the soldering tip in your mouth. Do not leave a hot soldering iron unattended and while camping NEVER sleep with a hot soldering iron in your sleeping bag. When soldering onto the wires of your ESC or any other circuit, solder as quickly as possible to avoid damaging the circuit with heat. If you ever get into an argument with a soldering iron, it’s best just to unplug it and leave the room for a few minutes while both of you cool down.

Kudos to the Creators of this Lighting System
I didn’t invent this lighting system. Not even close. I’m using Chimaera and Delorno’s system, which I found in this thread: http://www.rcgroups.com/forums/showthread.php?t=438925. Thanks, Chimaera and Delorno, for sharing a great design with us.

Play-by-Play
Here’s a play-by-play of the video with some details to help you understand what's going on, especially where the events are compressed to avoid boring viewers completely out of their gourds. The numbers in parenthesis correspond to the time counter on the video.

(0:06)
Strip out the small wires from a phone cord. You will need three positive lines of wire and three negative.

(0:11)
You will be running a positive and a negative to each wing and a positive and negative to the tail. The four wires for the wings should reach from the ESC to the wing tip, then along the side of wing tip, and then along about one-half of the trailing edge. The two wires to the tail should reach to the leading edge of the horizontal stabilizer and then be long enough to connect two LEDs on one side of the horizontal stabilizer. You can either double back to connect the LEDs on the other side or you can splice in separate wires for that side (I spliced in two separate wires for the other side since I thought the wire doubling back would look ugly).

(0:28)
Solder the three positive wires to each other and then to the Micro Deans plug (the side with two male connectors). Solder the three negative wires to each other and then to the other side of the Micro Deans plug.

(0:54)
Heatshrink to your liking. The Deans plugs came with some small heat shrink, so I opted to put that on first and then put some larger heatshrink over all three wires. Then pair up each negative with a positive – a positive and a negative for each wing, and a positive and a negative for the tail. With these pairings, you are now ready to begin soldering the LEDs to the wires. Please see the attached wiring diagram if you have any questions. Remember: the positive and negative wires DO NOT touch each other, but will terminate without touching each other directly (the electricity flows from the positive wire, through each resistor and LED, then into the negative wire.)

(1:45)
The longer prong on the LED is the positive. Bend it down at a 90-degree angle, away from the other prong. Solder the resistor to the positive prong. I prefer twisting the resistor lead around the LED a few times so there’s a mechanical connection in addition to the solder; then, after I solder, I trim the excess leads off. Try to avoid holding the soldering iron to the LED prong too long or it may burn out the LED.

(2:09)
Pick a wing and decide how close to the fuselage you want your first LED. Mine are about 2 or 3 inches in from the center of the wing. Rubbing the positive wire back and forth on the soldering iron, melt enough of the insulation off to make a good contact point. A quick way of doing it is to rub the top of the wire back and forth a few times, then the bottom, then rotate the wire 90 degrees, then rub the bottom and top again. This generally will clear enough of the insulation away. Just make sure there’s plenty of wire visible.

(2:15)
Wrap the free resistor lead several times around the newly cleared section of wire, then solder it and trim off the excess lead.

(2:43)
Measure the negative wire to see where the negative prong of the LED will connect without a lot of extra slack in the wire. Extra slack just means you’ll have extra wire. Melt the contact spot the same as with the other wire, and then twist and solder the negative lead onto that spot.

(3:23)
Test the first LED to make sure all solder connections are good, and that you didn’t somehow manage to wire it up backwards. Also, make sure the soldering iron hasn’t been sitting in your lap for the last five minutes. When testing the LEDs, avoid shorts by making sure none of the strands of wire are touching. I sometimes put a dab of hot glue on the ends of each wire or a little piece of black tape. I had previously spliced into the positive and negative leads on my ESC and soldered the other Deans Micro plug (with two female connectors) onto it. This makes testing very easy. It’s also nice to have the lights lit up when you hot glue them to your wing, because you can see exactly where the lights are focusing and hold them at the best possible angle until the glue cools.

(3:35)
Solder up 21 more LEDs. For the wings, I soldered on four white LEDs and then three colored LEDs, all spaced about 4 inches apart. Then after an 8-inch gap, I soldered on two more white LEDs separated by 4 inches. For the tail, I soldered two white LEDs to the bottom of the leading edge of the horizontal stabilizer. To find the contact points on the tail wires, lay out the wire along the fuselage to measure where the contact points should be.

(3:53)
Hot glue the LEDs to the plane. I attached the first four white LEDs to the bottom of the leading edge of each wing, then the four colored lights to the bottom of each wingtip. I attached the last two white LEDs to the top of the trailing edge of the wing. The reason the last two are on the top is to give you better visibility when the plan is climbing out away from you or at other angle when you can’t see the bottom of the wing very well.

Levier Gardner
Dec 19, 2007, 04:35 PM
What a great video!! :) And the play-by-play explanation is also very helpful. I picked up some great tips! Thanks You've about persuaded me to redo mine.

trevormatney
Dec 19, 2007, 06:19 PM
Very creative and informative video! I especially like the Loony Toons music at the end LOL. Next month when I attempt my first LED installation, I look forward to using your video as a guide. Thank you for taking the time to make and post this video! Thanks also to Chimaera and Delorno for the original setup scheme. Take it easy!
Trevor

trevormatney
Dec 19, 2007, 06:26 PM
Oh darn! I forgot to ask a question regarding the wisdom of using magnet wire inside of a structure. For instance in a wing that is covered with Solite. I would think that as long as the wire was hot glued in place so it could'nt move around or touch, that I would'nt encounter any problems? What do ya think? Thanks!
Trevor

Darth_Elevator
Dec 19, 2007, 11:10 PM
Oh darn! I forgot to ask a question regarding the wisdom of using magnet wire inside of a structure. For instance in a wing that is covered with Solite. I would think that as long as the wire was hot glued in place so it could'nt move around or touch, that I would'nt encounter any problems? What do ya think? Thanks!
TrevorTrevor, yes, I think magnet wire is fine as long as it's not in an exposed setup like a Slow Stick. I have magnet wire in two other planes that I intend on leaving, because I think it's safe enough. One of them is inside the structure of the plane, like you mentioned. It's a Glostik (by UAVPilot) and I ran the magnet wire inside different wing compartments so there's no way the postive can touch the negative (well, no way short of a horrendous crash). I can post some closeup pictures if you're interested. I also have a flying saucer and when I wired it up, I just made sure the postive and negative strands of magnet wire never crossed over each other. And the magnet wire is taped down reasonably securely so I'm not worried about incidental contact like I was on the Slow Stick.

Good luck with your build next month -- I hope you'll post your results. And I hope you fall in love with nightflying. Glad you liked the Looney Tunes at the end of the soldering vid.

trevormatney
Dec 20, 2007, 10:59 PM
Right on Darth! You can post any pics you think may help, or give me ideas, and I will appreciate it. I don't have as much time for building as I would like, but I definitely will be trying this aspect out ASAP. Will post some pics for sure. Once again thank you!
Trevor

Heart Thumper
Dec 21, 2007, 04:37 AM
Very cool. I look forward in changing my wires and led pattern. Again, if you rather have the red leds over the green leds, go for it. Like I said, you had the pattern first and I plan on doing some different stuff with my leds. Now I just need a little time.
Curtis

Darth_Elevator
Dec 21, 2007, 11:29 AM
Very cool. I look forward in changing my wires and led pattern. Again, if you rather have the red leds over the green leds, go for it. Like I said, you had the pattern first and I plan on doing some different stuff with my leds. Now I just need a little time.
CurtisI think I'm going to like the blue and green. I flew last night and it looks great. Yes, I flew it last night during the snow storm (snowproofed the electronics with plastic bags).

andrewwells13
Dec 26, 2007, 04:42 PM
This is EXACTLY what I was look for! A "How To" for this LED stuff. Doesn't look as difficult as I thought it would be... Just tedious.

Does it matter whether I use 2s or 3s LiPo's with this lighting system?

Diggs
Dec 26, 2007, 05:02 PM
This is EXACTLY what I was look for! A "How To" for this LED stuff. Doesn't look as difficult as I thought it would be... Just tedious.

Does it matter whether I use 2s or 3s LiPo's with this lighting system?

If you are connecting it to the RX then no. The output on the RX should remain about the same.

Diggs

MorrisM
Dec 26, 2007, 05:02 PM
Does it matter whether I use 2s or 3s LiPo's with this lighting system?

You can run the LEDs off any voltage, but you need to use a different resistor. A common practice is to set up for 5V and use the same power that runs your receiver. This can be a 4 cell nicad or the BEC from the ESC.
Here is an online resistor calculator you can use for any voltage.
http://www.superbrightleds.com/led_info.htm#calc

It really isn't difficult, just tedious, like you said.

andrewwells13
Dec 26, 2007, 06:13 PM
Ok, another question... I've already tried searching the forum and can't really find the answer. All I have are 4 channel, Berg Microstamp receivers. And I'm only using 3 channels because they're all flying wings. Is there anyway to run an LED system off of the 4th channel of my rx?

Diggs
Dec 26, 2007, 06:42 PM
I run mine off the rx and prefer to do that. Just makes it neat and clean. Use a web LED calculator and it will tell you what resistor to use with a 5V power supply, which the RX will supply.

Diggs

Darth_Elevator
Dec 26, 2007, 08:06 PM
This is EXACTLY what I was look for! A "How To" for this LED stuff. Doesn't look as difficult as I thought it would be... Just tedious.

Does it matter whether I use 2s or 3s LiPo's with this lighting system?I'm glad you found what you were looking for. Yes, tedious is the perfect word to describe building one of these systems. But worth it IMHO if you're going to do a lot of nightflying because the visibility is incredible.

MorrisM is right, you can use 2s or 3s lipos, just make sure you get resistors to match the voltage of your pack. There's another handy calculator here: http://led.linear1.org/1led.wiz

andrewwells13
Dec 27, 2007, 12:26 PM
Please excuse my ignorance here. But this LED voltage stuff is very new to me. Most calculators have 3 questions to help figure out what resistor to buy...

1. Source voltage?
2. diode forward voltage?
3. diode forward current (mA)?

Now, if I'm using LiPo's, I'm assuming that my answer to question 1 would be either 7.4v or 11.1v. However, I'm not sure what the answer would be to the other 2 questions. Can someone explain what the answer would be to the last 2 questions? Or what I need to know to answer those questions?

andrewwells13
Dec 27, 2007, 12:37 PM
I'm going by Radio Shack tonight. I'm planning on buying some LED's and resistors. I've already got the wire at home for this project. I'd like to make a strand of LED's similar to the video at the beginning of this thread. I'm planning on using a 3s (11.1v) 1000mAh LiPo to run the plane AND these lights. Any suggestions on what resistors to buy?

healthyfatboy
Dec 27, 2007, 12:43 PM
An LED is a Light Emitting Diode so what it is asking you is the forward voltage drop and the forward current through the diode to get it to work. It should be on the specifications for the diodes on some sheet (if you can find the sheet or the information online).

Darth_Elevator
Dec 27, 2007, 12:56 PM
Please excuse my ignorance here. But this LED voltage stuff is very new to me. Most calculators have 3 questions to help figure out what resistor to buy...

1. Source voltage?
2. diode forward voltage?
3. diode forward current (mA)?

Now, if I'm using LiPo's, I'm assuming that my answer to question 1 would be either 7.4v or 11.1v. However, I'm not sure what the answer would be to the other 2 questions. Can someone explain what the answer would be to the last 2 questions? Or what I need to know to answer those questions?The answers to #2 and #3 come from each LED. You might have to make two trips to Radio Shack, one to get the LEDs, then go home and plug in the numbers (that should be on the back of each LED's packaging), then back to radio shack to get the resistors. My LEDs are all 20 mA forward current, but I don't know if all LEDs are the same. The forward voltage is different for different colors. Here's where I get all my LEDs: http://stores.ebay.com/Chi-Wing-LED-product-shop_W0QQssPageNameZstrkQ3amefsQ3amesstQQtZkm. They come with matching resistors for 12V source voltage, which I've been using with no problem. Scroll down on the different LEDs listings to get an idea of what the forward voltages are for the different colors.

andrewwells13
Dec 27, 2007, 02:07 PM
Ok, so there is a big difference between using a 2s LiPo to power the system and a 3s LiPo. Looks like I would need different resistors for each. So I'll have to limit myself to one LiPo if I use this setup. I guess I'll stick with my 3s.

So... I found an equation on instructables.com (http://www.instructables.com/id/EMSIQG0YO9EV2Z9SYT/) for finding the resistors. Looks like if I'm using an 11.1v LiPo, 1.7v LED at 20mA... I would need a 470ohm resistor.

Is this what you would come up with?

Now... If I'm planning on making a lighting setup with like 20 of these LED's wired in parallel (like in the video in this thread) couldn't I use the same 470ohm resistors and just solder one before each LED?

Am I getting this? Or am I way off??

MorrisM
Dec 27, 2007, 05:47 PM
Andrew,
Yes, you are getting it. The resistor is correct for 1.7V 20 mA LED running from a 11.1V source.

Some comments though: :) ;)

Use 12V for a 3S lipo. The voltage will be over 12V on a fresh charge. The LEDs will still be plenty bright when the voltage drops to 11V.

1.7V is a bit low. I don't recall seeing any with that voltage. Do check the specs for the LED you will be using. Looking at a few just now I find voltage ratings from 2V for a yellow to 3.5V for a white. 20 to 30 mA current seems to depend on the brightness.

If you run from 12V source, you can run 3 to 4 LEDs in series with one resistor. Doing this will use less current than running 3 or 4 in parallel with a resistor on each LED. You can use a series/parallel network if you do it this way.
Some eBay LED suppliers include resistors. These are always for 12V(for use in cars) and one resistor for each LED.

You will spend much more $$$ buying LEDs from Radioshack. I hope you can find a way to order them online.

I found a great link for LEDs in models.
http://www.rc-cam.com/led_info.htm

Here is a nice LED calculator that will design your series/parallel array
http://led.linear1.org/led.wiz

andrewwells13
Dec 27, 2007, 06:44 PM
Very true... Resistors are cheap enough at Radio Shack... but LED's are EXPENSIVE!

Stevie Little
Jan 02, 2008, 11:27 AM
I just simply put a 1k resistor on each LED (red,white,yellow etc) run them on a 3s Lipo and everything seems to work fine....please correct me if i'm doing it wrong because it is new to me...Thanks Stevie

MorrisM
Jan 03, 2008, 05:27 AM
Stevie,
The LED voltage is not critical, and it's alway better to use a higher value resister to make sure you don't over voltage.
You might get more brightness from a 600 ohm resister, but if they are bright enough with the 1K ohm, no need to change it.

andrewwells13
Jan 03, 2008, 03:37 PM
The K's really threw me off at Radio Shack. 1K ohm = 1000 ohm... right?

Stevie Little
Jan 03, 2008, 04:34 PM
Thats Right

lextek
Jan 06, 2008, 06:09 PM
Here is an online resistor calculator you can use for any voltage.
http://www.superbrightleds.com/led_info.htm#calc



Can you tell me what the following are?

"diode forward voltage"
"diode rated current"

are these from the LED specs?

If a read the thread I would have already known the answer :rolleyes:

Diggs
Jan 06, 2008, 08:40 PM
yep, those are specs for the LEDs. Some vendors list those specs. I think Modsthatglow does. And I don't think that is in this thread until now :)

Diggs

cola2cool
Jan 23, 2008, 07:46 AM
Master:
There's a trouble to access to your video link here.
would u kindly send the video file directly to me by MSN or any other ways?
Thank you very mucn indeed

Darth_Elevator
Jan 23, 2008, 03:35 PM
Master:
There's a trouble to access to your video link here.
would u kindly send the video file directly to me by MSN or any other ways?
Thank you very mucn indeedLet's try a YouTube version to see if that works for you.

http://www.youtube.com/watch?v=i2j--gDLEME

MorrisM
Jan 23, 2008, 08:00 PM
Can you tell me what the following are?

"diode forward voltage"
"diode rated current"

are these from the LED specs?

If a read the thread I would have already known the answer :rolleyes:

Here is a typical spec page from superbright LED's. This is the first white LED on the list.

Continuous forward Current 30 mA
Forward Voltage 3.3 V

Kwooda
Feb 04, 2008, 02:30 AM
What I do not like about this setup is there is so much wasted power. Each resistor in the circuit represents power loss - power that could be used for producing more light, or power that need not be used in order to gain extended duration.
I think the circuit was designed with simplicity in mind - if you know your source voltage, and you've got a resistor matched up to each LED (and that can include different color LEDs, each with their own resistor, according to the LED specs), then you can just endlessly string them together in parallel for as many LEDs as you want on your plane (up to the output capacity of your batteries, that is).
Also, in a parallel circuit, the total power consumed by the circuit is the sum of each leg (LED+resistor) in the stack. If you are running a 4.8V NiCd pack, for instance, with LEDs that each drop 1.6V and you want to run them at 20mA, then you need a 160-Ohm resistor for each LED. Each leg is then drawing 20mA @4.8V, or 96mW of power. Of that 96mW, only 32mW is being consumed by the LED, and 64mW is being consumed by the resistor! That's like having two extra (dark) LEDs in the circuit - two thirds of your power is going into the resistors.
In addition, if you have 20 LEDs on your plane in this configuration, you are drawing 20 legs x 96mW, or 1.92W.
You could put two of these LEDs in series with an 80-Ohm resistor and now at least you have two thirds of your power going into generating lights. Moreover, if you still only use 20 LEDs, you now only need 10 legs in your parallel stack, each leg still drawing 96mW, so now you are drawing 10 legs x 96mW or 960mW. Half the power for the same amount of light!

It is best if you can match your LEDs to your batteries using the smallest resistor possible to provide the desired light. Many LEDs are rated between 20 and 60 mA, and most of the LEDs I have used produce ample light at 20mA, so play with your LEDs to see how bright they are at different current settings, and choose the lowest current that will provide enough light (to your liking), then note what their voltage drop is at that current rating (most do not vary more than about 0.1 to 0.2V from the specs) and calculate your resistor values based on that. Try to put as much power (voltage times current) into your LEDs and the least power into your resistors.