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I have a dragonfly (walkera) r/c helicopter but i haven't used it much in the past months. It's small and difficult to control, but i really like it.

WL -> code POPSCI 10%off (and no wickedbucks) taken from: http://www.retailmenot.com/view/wickedlasers.com

:o $4k lost? holy sh*t! if there's anything we can do tell us, there'll be tons of people here wanting to help you recover the money.

Ah I finally did it! it was just a matter of aiming accurately to the head of the match for a couple of seconds. :) :) :)

yeah, i said parallel, read it again lol ;) There's something i really recommend for simulating circuits. Much easier than solving equations: www.ni.com/multisim

Yellow and green leds have about 2.5V drop, so they're the most similar. But they'll burn unless the current is quite low (they usually glow red first, that's a first warning you're going to break it), so you'd have to use several in parallel to test high currents.

That's an important point about the resistance: first make sure you measure 10% or 20% tolerance resistors because that can be a significant variation in current in this particular application. And second, most potentiometers have like 2 ohm resistance minimum, and that adds up too. So don't...

Regular matches. Safety matches i guess, not the ones with white heads.

I always kept gunpowder unmixed until the day i'd use it and i kept it dry at all times with silica gel bags. Anyway the sulfur was not really essential but it enhanced the mixture, i sometimes made odorless powder by using just carbon and chlorate in the right proportion. The only time i had a...

I used to make my own fireworks when I was 16-18. I have since dropped the hobby, but it was fun while it lasted. I made firecrackers, smoke bombs, fuses... the most common gunpowder i made was potassium chlorate + sulfur + carbon +magnesium. But I tried lots of combinations, potassium...

I have the same "saturn" pattern on my GB diode at low power (on both i've tried so far), I think they're all like that. Anyway, i've been trying to burn matches and i can't get them to ignite. I focused the aixiz module properly and i went up to 180mA current. Maybe I need to point it more...

Actually, you can sometimes see through some clothing in near infrared. In particular, some bikinis are somewhat transparent in IR. But yes, I guess those glasses are pretty much useless. Also, any cheap sunglasses are probably just as good as those glasses, because many cheap sunglasses are...

I played DD a couple of times when I was a kid, but I've played other RPGs much more (MERP, rolemaster, star wars, blood bowl...). I stopped playing when i was about 14 though... that's 12 years ago now. We also invented a football rpg at school, it was lots of fun until it was banned in school...

Yep. What the hell is "4 congo blue and 1 primary red" ? I suggest an alternative method: just remove the IR-cut filter from a webcam and see IR with it. If you want to filter out visible light use a photographic IR filter (Hoya R72 -lets >720nm light pass- is the most common and cheap) or use...

Hi! I don't remember how i came here (i was just browsing and ended up reading the forum). I think this is a great forum and lasers are interesting stuff. I've always been into electronics and so on so I feel "at home" here :)

Maybe a IR-cut photographic filter on the laser will do, instead of blocking ir with your goggles. You can get one from an old webcam you don't want or are not using anymore; the ir-cut filter is right in front of the sensor, then use the webcam to "see" IR (that's why they have the filter, they...

Good sunglasses block some IR (more or less the same as visible light). Bad ones don't even block IR. So it's a bad idea to rely on sunglasses anyway.