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Old Dec 10, 2012, 12:51 PM
Stop me before I build again!
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Quote:
Originally Posted by WiseDuck View Post
Things suddenly got complicated. In that case I won't bother with the leds.
It looks complicated but it's really not; figure out how many leds, what color, and the max voltage and one or more of the calculators out there will give you the resistor you need to wire in to prevent it from exploding.
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Old Dec 10, 2012, 01:18 PM
Mmmmmmm!
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Hrm, alright. I see it now, so I need two 39 ohm resistors if I want to power these with the receiver. Shame I didn't know about this before, feels kind of silly to order such a tiny amount of stuff from that Po... something, place. Maybe I can find more things on that website that are good to have.
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Old Dec 11, 2012, 05:38 AM
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Whoo missed a lot it seems, damn mailer didnt alert me..

3x2 props are press-on, HOWEVER they do not fit the 2 gram motors!
I have to figure out a way to get these buggers on securely,
I was thinking of either glue or somehow squeezing some stripped wire casing in between.

Wiring LEDs without voltage given is a bit tricky, I suppose just start with 1,5v and see if its bright enough.

And a frame, I suppose I could make you one, Wiseduck, but im worried people will jump me with requests.

How many resistors do you need? I might be able to help.
I bought a buttload of em off of ebay a while ago.
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Old Dec 11, 2012, 06:04 AM
Mmmmmmm!
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Well, according to the calculations above I need 2 resistors between 33 and 39 ohms. I believe you can find 33 ohm and 39 ohm resistors out there. So yeah, I need two.

Well, you can just say no, can't you? :P I can pay a bit for the frame if you want, anything to get started faster. Once I have a program for the mill I'll work on the CF frame for 2.5" props or 3" props.
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Old Dec 11, 2012, 06:25 AM
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I thought you were gonna do 1 led per ESC to deal with tiny BEC capacity, ergo 8 resistors.
But if its just 2 I can chuck some in the envelope if you want, no probs.

I'm gonna cut a 3"prop version this weekend, so if you want I can run one through for you if you'd like.
Ill shoot you a PM with the details.
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Old Dec 11, 2012, 06:41 AM
Mmmmmmm!
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Kingdom of Sweden, Dalarna County, Sater
Joined Oct 2011
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Well, according to that LED calculator thingie.. I just need 2.

5 volts from receiver.
Voltage drop across LED, 2v
30ma per led
4 LEDs, one per arm.



Quote:
Exact calculated resistance 33 Ohm
Nearest higher rated resistor 39 Ohm

Wattage recommendation for the resistor 1/8 watts
Circuit's total current consumption 51.3 mA
Actual Single LED Current 25.6 mA
Power dissipated by the LED 51 mW
Power dissipated by the Resistor 26 mW
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Last edited by WiseDuck; Dec 11, 2012 at 06:47 AM.
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Old Dec 11, 2012, 07:06 AM
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Oy, that ll be a nice spaghetti. Thats another reason I chose ESCs with BECs.
I can just lump em on to the ESC with a resistor and theres no wire going anywhere.

Idea, you should use a copper layered PCB to cut a frame. Common ground, half the wires.
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Old Dec 11, 2012, 07:13 AM
Stop me before I build again!
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I would be less worried about a few extra inches of wire which can be easily routed vs driving even more off the 5v regulated voltage since that micro 5v boost is only rated for 200mA.

OTOH, looks like 8 LED's ( 2x arm ) would be 200mA, just wire them to a second 5v boost.
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Old Dec 11, 2012, 07:25 AM
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The turnigy ESCs have a 500mAh BEC, so my build is safe in that regard.
I just hope the ESCs wont give me any crap for running them on a quad.
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Old Dec 11, 2012, 07:45 AM
Stop me before I build again!
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At 2.9g this seems like a good alternative if you want to drive more than 200mA on 5v.

http://www.hobbyking.com/hobbyking/s...to_5v_1A_.html

Strip it down and wire it to the FC.
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Old Dec 11, 2012, 07:49 AM
Mmmmmmm!
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We'll see how I solve this one. I bought two different boosters over at HK, just to be safe.
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Old Dec 11, 2012, 08:05 AM
Stop me before I build again!
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Quote:
Originally Posted by Freakazoid View Post
3x2 props are press-on, HOWEVER they do not fit the 2 gram motors!
I have to figure out a way to get these buggers on securely,
I was thinking of either glue or somehow squeezing some stripped wire casing in between.
What about heat shrink on the shaft?
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Old Dec 11, 2012, 08:11 AM
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I tried that, unfortunately it just shears off rather than going through.
The wire casing didnt work either, same problem.
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Old Dec 11, 2012, 08:15 AM
Stop me before I build again!
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Does anything in this hobby actually go together nicely?
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Old Dec 11, 2012, 08:49 AM
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Hobbyking and my bank account, thats about the only thing that goes together "nicely".

Im thinking about drilling the prop out to 2mm and then cramming.. something.. in it.. I dont know.
Would just globbing the bastard full of rubber cement and pushing it on work in any way?
Its just 37 grams pulling on it in the end, but not sure which will win.
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