Halloween is Approaching! Questions about 5mw Green

[Tim71]

Hi all,

This Halloween, I would like to create a vortex/tunnel in the garage for the kids to see. I would be using a 5mw pen from eBay that I just bought. A fog machine would be used to help with the effect.

My questions are:

1. Can the 5mw green eBay pens run continuously for 1.5 hours? I'm assuming the temp. outside will be around 58-64 degrees F. And if it would help, I could wrap some aluminum foil around it to dissipate some of the heat.

2. Would this be considered safe or not? I would make the tunnel large enough for the kids to walk inside the center, however, there is always the chance that the edges of the circle could get into their eyes.

I came across this article on laser vortex safety: Haunted.HyperReactor.com - Laser Vortex safety


Does anyone have any constructive thoughts on the matter?

Thanks

 

[mewrox99]

I don't think it will be able to survive 1+ hour

 

[kiyoukan]

yeah with that much time you will kill the batteries if the temp does not first.
i would sugest that you use something mor than foil. i know you dont have acces to any high tech equipment so there is one easy way to increase thermal mass but its a bit messy.
get a plastic container cheap kind and cut a hole in the side for your laser beam and then glue some glass over the hole you can get glass from hobby shops or micro scope slides.
then make sure you have something holding the laser so its pointing out the hole then fill the whole thing with mineral oil.
You must use mineral oil due to it does not conduct electricity.
this will allow the laser to run for huge amount of times but its a bit messy once you are done. to clean let sit in different positions for a few days then use rubbing alcohol and some q tips.
its simple and cheap.
as far as 5mw if it is 5mw, i would say its safe enough, spot and strobe lights would do more damage (if close enough).

 

[millirad]

Yeah, probably safe so let the kids have some fun. Remember though that a laser having a sticker of 5mw attached can easily be over-spec. and might put out a lot more power, so no guarantees. Also a wider angle and faster motor work in your favor. It takes very proactive supervision of children around lasers, because they will grab your device or put their face right up to the mirror, and that would be a big problem.

 

[Tim71]

Thanks everyone for the comments/suggestions. I also have a red 5mw that I could use while the green cools down. I have only used these for very short duty cycles (10-45 seconds), and didn't know for how long they could be pushed.

The kids will be at least 15 feet away from the mirror, the motor I'm using is fast, and the diameter of the projected 'circle' is about 10 feet, so it looks like it will be safe. I'll do a dry run the night before, and hopefully get it up on YouTube.