How would you build this? (UFO beam)

TheIrishAvenger · Post by **TheIrishAvenger** » Wed Oct 07, 2009 2:36 pm

Here’s what I need: In a cylinder about 1 ½ “ in diameter, and about 1” tall, I need to create a light that is bright enough to shine through about a foot of colored acrylic rod to create a beam effect. I was thinking an LED penlight, modified to fit.

OR

How ‘bout a green laser pointer, 15-35mw, mounted in same dimensions as above, modified to have the switch about a foot away. Will the beam melt a painted piece of styrene at about one foot range? From what I'd read it'd take around 75mw to actually melt plastics.

Just an informal poll to have you guys bounce ideas off me. How would YOU do it?

Thanks!

Chris

mastermodelreview · Post by **mastermodelreview** » Wed Oct 07, 2009 4:49 pm

Just put small candle under it, with a small laptop fan on top (pointing away from the candle) then just drop some magnesium powder and lighter fluid on it once and a while to enjoy real melting beam effect.

tetsujin · Post by **tetsujin** » Wed Oct 07, 2009 5:06 pm

TheIrishAvenger wrote:How ‘bout a green laser pointer, 15-35mw, mounted in same dimensions as above, modified to have the switch about a foot away. Will the beam melt a painted piece of styrene at about one foot range?

I doubt it - but be careful, there's liability issues that come into play if you take your laser to model shows and such... Inadvertently taking in too much of the light could really hurt someone's eyes, after all...

en'til Zog · Post by **en'til Zog** » Wed Oct 07, 2009 7:10 pm

I'd look up a couple of really bright LEDs, or a single killer bright one like the G16642 ( $2.49 @ ) from the Electronic Goldmine (www.goldmine-elec.com) which puts out 265,000 MCD at 3.4 to 3.8 VDC at 100 mA (yeah, 265 Candella). That's actully the power drain of an old time flashlight bulb, but a whale of a lot more light output.

I think you can power it with a suitable 3.6 volt lithium primary cell (nonrechargable).

They also have some very nice 5mm WHITE ones that just need 3.6 VDC at 20 mA that should work too.

Kylwell · Post by **Kylwell** » Wed Oct 07, 2009 8:30 pm

You'd also want to look for narrow angle LEDs. If the acrylic is water clear tho' you'll get no beam effect.

photoguy · Post by **photoguy** » Wed Oct 07, 2009 8:35 pm

Yep. You'll want one super bright LED, and you'll want to frost the acrylic rod to give the light something to scatter around on and produce a nice glow. No need for a laser, it'd be too bright.

Stu Pidasso · Post by **Stu Pidasso** » Wed Oct 07, 2009 11:50 pm

Is the beam expected to hold any weight? If not, why not try one of those colored transarencies they use in schools, and put the LED in the top/bottom of one of those?

If it is supposed to hold some weight, then try a colored hamster tunnel, and cut to fit.

EDIT: Oops I just re-read it, you already have the rod. So why go all high tech? Just tear apart an old flashlight, and use the bulb from that.

Andrew Gorman · Post by **Andrew Gorman** » Thu Oct 08, 2009 12:21 am

I've seen some really nice scale sheets of water done with thin plastic film, like dry cleaner bags, dipped in clear resin. Something like that could work- check out model railroad sources for waterfall how-tos, and model ship sources for "green sea". No need for a real death ray, just the illusion of one! Just a suggestion.

en'til Zog · Post by **en'til Zog** » Thu Oct 08, 2009 1:32 am

Maybe put the light at the bottom and have a mirror at the top? Or at least have a mirror at the bottom to bounce more light back up the tunnel/rod.

Chacal · Post by **Chacal** » Thu Oct 08, 2009 9:41 am

en'til Zog wrote:Maybe put the light at the bottom and have a mirror at the top? Or at least have a mirror at the bottom to bounce more light back up the tunnel/rod.

I second that. It allows for a bigger 'bulb' (in both physical size and power consumption) and avoids the 'wire up the rod' problem.

For a whole foot of rod, it'll be difficult to keep the light from being uneven, but hey, nothing is perfect. You may get different results if you use instead of a mirror on the model's end, a bit of white/silver paint or a reflective sticker (there would be a slightly stronger glow concentrated on the model's bottom, making it look like that's the origin of the 'energy'). Look for high output LEDs, like Luxeon™.

TheIrishAvenger · Post by **TheIrishAvenger** » Fri Oct 09, 2009 7:07 pm

Well, looks like I"m gonna go with a blue tinted acrylic cylinder and mount the LED's at the top end. I did some experimenting with this and it puts off a pretty good glow of light at the bottom, even without using a mirror or any amplification device, so the "abductee" figure will be nicely lit. I have the UFO lighting yet to do, but that should be easy. I worked on windows and lightboxes last night and today. Lookin' good. Thanks for the tips, guys.

Chris

davidlgreen · Post by **davidlgreen** » Sat Oct 10, 2009 9:06 am

i believe PLASTRUCT sells colored acrylic tubing. and lots of other cool stuff.
free downloadable catalog

Mr. Engineer · Post by **Mr. Engineer** » Sat Oct 17, 2009 9:58 am

Basically, what you're doing is almost like what I did. For a lightsaber.

If you can, try to get a hollow acrylic tube and then, try to sand the inner walls. When you put in a bright LED or even a 1watt Luxeon, you would get a nice straight beam.

http://www.chowfookcheong.com/Lightsaber/Lightsaber.htm

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How would you build this? (UFO beam)

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