So did I just waste some coin on this red laser?

Hi Guys, first post so try and go easy on me!

I just purchased a red laser off E-Bay. What I'm looking for is a beam, that can seen at night at say a distance of 1/2 mile or less. No I don't want to start fires, or pop balloons, just make a red line into the night sky.

So can anyone guess if this laser will do the job? Or did I just purchase something that will be basically a dot producing pointer?

It's E-Bay item # 350144242368 <Just found out I can't post a link!>

Thanks!

Tommy D

Re: So did I just waste some coin on this red lase

Tommy_D said:

Hi Guys, first post so try and go easy on me!  
I just purchased a red laser off E-Bay. What I'm looking for is a beam, that can seen at night at say a distance of 1/2 mile or less.  No I don't want to start fires, or pop balloons, just make a red line into the night sky.
So can anyone guess if this laser will do the job?  Or did I just purchase something that will be basically a dot producing pointer?
It's E-Bay item # 350144242368 <Just found out I can't post a link!>
Thanks!
Tommy D

Click to expand...

That's a really nice cat toy.  You will not be seeing a beam shining into the night sky (unless it's really foggy)

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350144242368

Peace,
dave

Re: So did I just waste some coin on this red lase

Thanks Dave! Now without a cat I guess it's just plain useless!

I purchased a green one about a year ago that is rated at 30mW and produces a really nice beam in the dark. Could you suggest a similar one, but in red?

Thanks much!

Tommy D

Re: So did I just waste some coin on this red lase

red lasers need to be VERY powerful to see a beam because your eyes aren't as sensetive to them as green ones. even my 250mW red one is kinda hard to see in a lit room

Re: So did I just waste some coin on this red lase

Thanks Max. I do understand that a red laser must be more powerful then green to see. However mine will only be used in near complete darkness outside.

Tommy D

Re: So did I just waste some coin on this red lase

you will still need about 150-200mW for near pitch black

Re: So did I just waste some coin on this red lase

Tommy_D said:

Thanks Dave!  Now without a cat I guess it's just plain useless!
I purchased a green one about a year ago that is rated at 30mW and produces a really nice beam in the dark.  Could you suggest a similar one, but in red?
Thanks much!
Tommy D

Click to expand...

MaxKillz is right on. You will NOT even approach the visibility of your 30mW green with 200mW of red. The human eye just cannot "see" red as well as green.

Peace,
dave

Re: So did I just waste some coin on this red lase

Thanks for the spec Max.

Perhaps if I explain what I'm using the laser for you can be of some more help.

I fly model airplanes at night. The models are illuminated by many, many LEDs. However as you might imagine it's easy to loose orientation at night while flying the model. So that said the left wing has Red LEDs and the right wing Green LEDs. So what you see is red, right return, if you know what I mean.

Anyways if I could arrange to carry a small laser on each wing a quick blip of laser light would help with orientation very quickly.

Keep in mind the laser must be light no more then say 4ozs less batteries.

If I can't come up with a decent red one, then I will just have to go with 1 green.

Thanks!

Tommy D

Re: So did I just waste some coin on this red lase

Interesting... I note the spec you used was 200mW. The place where I purchased my green one has a 200mW unit but they will NOT ship to the USA?!?

Aside for bulking up on some reading is their any option?

Lastly can I ask what the amp draw one one of these units is on avg? I intend to power it with an external 2200 ma battery.

Thanks again guys, it's nice to get so much help so fast.

Tommy D

Re: So did I just waste some coin on this red lase

some reading would help a lot


you could make one yourself with a 16x or 20x dvd burner in an aixiz module running off of a flex or rkcstr driver at about 400mA to give you roughly 200mW after the plastic lens

Re: So did I just waste some coin on this red lase

It'd be best to just leave the module on the plane, not the complete laser. The best option, since it is the most visible and the cheapest, would to have a 5mW green on there.

Re: So did I just waste some coin on this red lase

I have one worry with this idea, the fact that high powered lasers are being put onto a plane where the wings are moving. Doesn't that present the risk of him shining himself in the eyes with the laser or someone else as well?

Re: So did I just waste some coin on this red lase

It would be very unlikely that you would hit a bystander in the eye, even if it happened it would be even more unlikely to cause any eye damage to anyone as, I would guess, any flash would be for microseconds due to the movement of the plane.... I would be inclined to incline the lasers upwards at an angle to decrease the risk still further.

Are you using electric motor or glow/diesel? if you are using IC engines, point the lasers angled out facing backward (or even crossing), you may find the exhaust would help visualise the beams.

Red beams need to be even stronger if you are looking at them in any other direction than directly away from you or directly toward you.

Regards rog8811

Re: So did I just waste some coin on this red lase

Hmm, I'd suggest actually not going for the red at all. This is why:

1. To get decent beam with red, you need really high power, unless you are within inches from the beam looking toward the source (I can see the beam of my 5mW red in my house at night with curtains drawn and lights off, only when my eyes are like 2 inches from the beam. Looking toward the laser source)

2. To get such high power, you'd need lots of current, i.e. 400mA, or 300 at the very least. This means lots of heat! which means u'd need a good heatsink to cope, and that'll add extra weight to your plane.

3. Lasers have a duty cycle. Most people don't run their lasers for more than a minute continously for burning stuff, or the diode will go, since we are already pushing them to the limit. I take it that once you mount it on your plane, you'll be flying it for 10mins or so continously (or at the least 5mins).

4. Some danger issue, since a 200mW laser even from far away like 100m, is still extremely bright and may blind you, since for class 3R or 3B lasers, your blink reflex is too slow for it, and worse is that you are flying it at night, which will mean your pupils are dilated, allowing even more laser light to enter. If you use goggles, then you can't see the beam.

I'd advise to just stick to green. Although I think it's still a possiblity if you have, like what rog said, a plane running on fuel, which the exhaust may help.

Re: So did I just waste some coin on this red lase

I think this is likely to attract the wrong attention. The last thing you want is a confiscation by the police.

Re: So did I just waste some coin on this red lase

Mounting a powerful laser on a RC plane sounds like a dangerous plan... those things can end up anywhere due to user error or malfunction, and who knows what idiot will pick it up and look into the 'nice red light'.

A low power green would be best, relatively visible but not too dangerous. They do eat a lot of battery power too tough, 200-300 mA for a 5 mW is no exception. 30 mW's usually require the same amount of power, they are just more efficient.