Crazy reflector idea... environmental friendly.

Hi cpfers,
I don't know if this has been done before..

I was emptying the recycle bin for plastic and found lots of bottles. 1Litre, 2Litre, 600mils and etc. Looking at them I was thinking if the cone area is suitable for reflector purpose.

Chrome spray paint will do a nice mirror finish for reflection(orange peel not included) and the opening is already there for bulb fixture.

So is the angle all right? I haven't got any chrome paint so I am going to use some kitchen al. foil to try it later tonight. I have a feeling it will be a waste of time. It will be great if I can recycle these plastic bottles for reflector uses. /ubbthreads/images/graemlins/crazy.gif

Vince.

I would be interested to know how you go with that one,
how shiny is the chrome finish paint by the way ?
close to mirror ?
I am not familiar with chrome paint but I am interested, because I have a similar use........

Re: Crazy reflector idea... environmental friendly

The chrome spray paint I used several years ago was good. But fingers can quickly smudge and destroy it. It's a bit darker than plated chrome. The mirror wasn't great but much reflective than silver spray.

Re: Crazy reflector idea... environmental friendly

I wonder if Mag will steal this idea and use this in their next series of lights.

If this idea works, you gotta upload pics /ubbthreads/images/graemlins/smile.gif

Good luck

Geoff

Re: Crazy reflector idea... environmental friendly

Ok the kitchen al. foil sucks big time. I couldn't make any hotspot no matter how I adjust the bulb height. I am using the 1 Litre bottle cone. Try again tommorow with chrome spray, too dark to buy one now /ubbthreads/images/graemlins/frown.gif.

Vince.

Re: Crazy reflector idea... environmental friendly

My biggest concern would be heat. It wouldn't take much to warp or melt that kind of plastic.
If you are looking for cheap or free relectors, check out a burned out bulb from an overhead projector.

Re: Crazy reflector idea... environmental friendly

My guess is the curve is wrong.

You could check by cutting a slice out of the bottle say half an inch wide and laying it out carefully. Plot what happens when parallel 'rays' from down range hit the reflector. If they don't come to a point, you've no focus to put the emitter in.

Most similar shapes won't work. Just looking at a few bottles around the house it looks to me like they focus to a line, not a point.

For the truly serious, aluminum can be vacuum deposited on the plastic, same as glass mirror blanks. A first rate front surface mirror is easy to make this way. Food for thought.....

Doug Owen

Re: Crazy reflector idea... environmental friendly

You guys are right. Being a LEDdy I didn't have much concern about heat. The al. foil didn't have enough reflectivity so I had to spray some 'clear' paint. Then I used a hairdryer to blow dry. The lips started to melt inwards which is a cool effect /ubbthreads/images/graemlins/crazy.gif and that's it. So as DBrier said, heat is an issue for thin plastic.

I haven't tried the chrome paint yet, at this stage I am quite reluctant to continue /ubbthreads/images/graemlins/frown.gif

Vince.

Re: Crazy reflector idea... environmental friendly

I believe Ginseng had done a similar mod/fab. It was one of his 'ghetto mods' [as he referred to them as.]
He used a top of an old yogurt bottle, IIRC.
Pretty cool!
Here's the link. UltraGhetto Torch
These types of mods also show creativity, don't you agree? ...Not to mention, a great sense of humor!
Keep us posted and keep up the good work!
Danno

Re: Crazy reflector idea... environmental friendly

Hi,

I think the greatest shortcoming you're facing is not one of reflectivity (as even flat white paint van have a pretty high level of total reflection) but one of reflector profile. Almost all flashlight reflectors are parabolic, designed to focus a point source (filament) into a parallel beam. i doubt you would find even an approximation of a parabolic profile in a bottle. But I do like your enviro-friendly idea /ubbthreads/images/graemlins/smile.gif

Wilkey

Re: Crazy reflector idea... environmental friendly

If the implementation doesn't match the objective, why not change the objective? It looks like you won't get much throw from a bottle reflector. But perhaps it would make a dandy flood light.

Some flashlights are designed to give a flood beam because that is what's wanted for a particular application, such as reading or illuminating a large work area. I think that in such an application the objective would be to maximize the proportion of the light getting out the front. A broad beam would be prefered to a narrow beam.

It would be interesting to find out how good a flood could be obtained from different shapes and from differences of depth of light source within the reflector.

Regarding the color of paint to use, there have been a number of discussions. In this thread, Illuminated advocates the use of white paint.

Paul

Re: Crazy reflector idea... environmental friendly

Wow thanks for all the ideas people. I will always look for parabolic cone shapes.. Maybe I will live on bottle drinks from today onwards /ubbthreads/images/graemlins/grin.gif.

Ginseng I knew you will chip in! /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/thumbsup.gif your da best ghetto master.

Re: Crazy reflector idea... environmental friendly

Aww shucks,

I'm /ubbthreads/images/graemlins/blush.gif How about a straight cone?

Wilkey