redbird300
07-24-2009, 12:28 PM
Hi guys, this is a homemade small electrical project I wanted to share with all of you.
Hope it is useful for some of you, this decription took me some time to write.
First of all: thx again to Erwin, this kinda is his idea, he made a first draft by putting lights at the skids and the tailfin of his heli, and I was just lucky enough to find the time to do it in another way, enjoy !
Why ? Well, in the evening we are having trouble to keep our orientation due to lower lightconditions. Applying bright colors to our helis wasn't enough. So some lights seemed a good idea.
What did I want ?
a) as much light as possible off course
b) very low power consumption and weight (look further down for these items)
c) no extra screws or holes in the heli to drill
d) only 1 short cable
e) no soldering at the ESC, preferably a system with a plug
f) nothing to plug or unplug before each flight, lights go on with the battery connected to the ESC
g) cheap ! in fact, this project costed only 6 euros = 8,5 $. That's for the 3 LED's and the metal holders. The other stuff was laying around, but is dirt cheap
h) not to ugly, lol
You can see the result in the pictures in this and the next post.
A guideline to make this yourself:
Part 1: The electrical part:
Get some ultrabright white LED's at your local electronics shop. I used LED's from "KingBright" 5 mm diameter. Look at http://www.kingbrightusa.com/default.asp for their catalogue. These LEDs have 7000 mcd, are even available up to 10000 or more mcd light intensity, and come in different colors.
Mine take about 12 milliAmps each at 3,4 Volt (between 10 and 15 milliAmps is OK).
This means they have an internal resistance = 283 ohms.
But at 5 Volt (BEC exit, could also be 5,5 or 6 Volts!) and 12 milliAmps you would need 417 ohms to keep the current equal.
So a resistor = 417 - 283 = 134 ohms in series with the LED is necessary.
If you put 3 pieces in parallel AND use only 1 resistor for the three LEDs like me, divide the resistor value by 3, simple as that. Never go lower, only slightly higher if needed. I took a resistor = 47 ohms. It is hidden under the yellow shrink wrap in the pictures, you can barely see it. And my power consumption is under 40 milliAmps, no LIPO would ever mind that.
Part 2: The mechanical part:
You need some metal or plastic LED holders with your LED's (also at the electronics shop, watch the diameter), there are some you can click on, and others like mine have a big nut and washer to screw them on a given surface.
Further more I used a piece of alu profile = 56 mm long x 15 mm high x 15 mm wide x 1 mm thick.
The pictures speak for themselves now, I guess. Just drill the appropriate holes for the LED holders and the 2 skid screws at the other side.
The weight of the finished project, including everything, even the servocable and shrink wrap = 17,4 grams. But it is very close to the COG, so not that important. You could get the weight down by using a plastic profile and plastic LED holders (I don't like plastic on my alu CopterX, lol).
You fix everything with the 2 skid screws. Solder a servo cable to the LED's+resistor, and plug it in a spare channel, or use a Y-servoharness and hence use any channel in use. Done ! Off course, you only want to use the black/red or brown/red (with Futaba) wires ! The upper wire is the signal cable (often white or orange), cut it off, you don't need it. And remember that LED's have a polarity, they won't work if they are reversed, just change the wires then.
Some general remarks:
a) you could use the same system in front, but is of less use, you already have better orientation with a bright colored canopy.
b) the metal piece can also be used as a license plate holder for your heli :-)
c) dimensionenineering has something similar, look at http://www.dimensionengineering.com/EasyLights.htm. If you have a spare channel, you can even swith these on and off with the TX in flight ! Real gadget. But you still have to find a way to fix these in a good orientation...
d) the last picture where the heli is sitting at the end of a long table was taken by normal daylight. Not bad for 3 little LED's, IMHO.
Your humble servant, Raf :-)
Hope it is useful for some of you, this decription took me some time to write.
First of all: thx again to Erwin, this kinda is his idea, he made a first draft by putting lights at the skids and the tailfin of his heli, and I was just lucky enough to find the time to do it in another way, enjoy !
Why ? Well, in the evening we are having trouble to keep our orientation due to lower lightconditions. Applying bright colors to our helis wasn't enough. So some lights seemed a good idea.
What did I want ?
a) as much light as possible off course
b) very low power consumption and weight (look further down for these items)
c) no extra screws or holes in the heli to drill
d) only 1 short cable
e) no soldering at the ESC, preferably a system with a plug
f) nothing to plug or unplug before each flight, lights go on with the battery connected to the ESC
g) cheap ! in fact, this project costed only 6 euros = 8,5 $. That's for the 3 LED's and the metal holders. The other stuff was laying around, but is dirt cheap
h) not to ugly, lol
You can see the result in the pictures in this and the next post.
A guideline to make this yourself:
Part 1: The electrical part:
Get some ultrabright white LED's at your local electronics shop. I used LED's from "KingBright" 5 mm diameter. Look at http://www.kingbrightusa.com/default.asp for their catalogue. These LEDs have 7000 mcd, are even available up to 10000 or more mcd light intensity, and come in different colors.
Mine take about 12 milliAmps each at 3,4 Volt (between 10 and 15 milliAmps is OK).
This means they have an internal resistance = 283 ohms.
But at 5 Volt (BEC exit, could also be 5,5 or 6 Volts!) and 12 milliAmps you would need 417 ohms to keep the current equal.
So a resistor = 417 - 283 = 134 ohms in series with the LED is necessary.
If you put 3 pieces in parallel AND use only 1 resistor for the three LEDs like me, divide the resistor value by 3, simple as that. Never go lower, only slightly higher if needed. I took a resistor = 47 ohms. It is hidden under the yellow shrink wrap in the pictures, you can barely see it. And my power consumption is under 40 milliAmps, no LIPO would ever mind that.
Part 2: The mechanical part:
You need some metal or plastic LED holders with your LED's (also at the electronics shop, watch the diameter), there are some you can click on, and others like mine have a big nut and washer to screw them on a given surface.
Further more I used a piece of alu profile = 56 mm long x 15 mm high x 15 mm wide x 1 mm thick.
The pictures speak for themselves now, I guess. Just drill the appropriate holes for the LED holders and the 2 skid screws at the other side.
The weight of the finished project, including everything, even the servocable and shrink wrap = 17,4 grams. But it is very close to the COG, so not that important. You could get the weight down by using a plastic profile and plastic LED holders (I don't like plastic on my alu CopterX, lol).
You fix everything with the 2 skid screws. Solder a servo cable to the LED's+resistor, and plug it in a spare channel, or use a Y-servoharness and hence use any channel in use. Done ! Off course, you only want to use the black/red or brown/red (with Futaba) wires ! The upper wire is the signal cable (often white or orange), cut it off, you don't need it. And remember that LED's have a polarity, they won't work if they are reversed, just change the wires then.
Some general remarks:
a) you could use the same system in front, but is of less use, you already have better orientation with a bright colored canopy.
b) the metal piece can also be used as a license plate holder for your heli :-)
c) dimensionenineering has something similar, look at http://www.dimensionengineering.com/EasyLights.htm. If you have a spare channel, you can even swith these on and off with the TX in flight ! Real gadget. But you still have to find a way to fix these in a good orientation...
d) the last picture where the heli is sitting at the end of a long table was taken by normal daylight. Not bad for 3 little LED's, IMHO.
Your humble servant, Raf :-)