What would I call this? A focusing ring? ........... V2 is going into testing soon.

Flashlight Modding and DIY Parts
1

Over the years, I have played around with using some type of ring/collar surrounding a led, to direct light back onto the die in hopes of improving the beam, or creating a tighter beam. Since I'm mostly a hack and since science and mathematics are only strange sounding and meaningless words to me, I think people who can do those things beat me to it. (Wavien).

But, I still play around with the stuff once in a while and I wanted to play with an MT-G2. My goal was to make a "thrower" out of it, with something that was very cheap and readily available.

I didn't really succeed, but what I did come up with was a beam profile for the MT-G2 that I like very much and may even use it in a light or two.

So, I will show you what I did and you can see the crazy old fart come up short once again...

or1a

Please excuse the mess. I made a makeshift 1 meter testbed for measuring lux output, so I could get some kind of comparison data.

ol1b

This is one of the 5000k MT-G2 leds from Cutter and I put in on an aluminum heat sink. I soldered thin copper tabs onto the contacts, so I could get low to the die face with the reflector. The Kapton tape was for insulating the contacts from the reflector. I used a 52mm reflector from CNQG. I have used many of them in Maglites and I opened this one up to fit a ring on the bottom. A ring that would face toward the die, like a small reverse reflector.

ol1c

I will explain what the ring is made of later.

ol1e

I am using two efest IMR 14500s for power and just some jumper wires to connect.

ol1d

So I started out with the bare reflector sitting right down as low as it could go, just to have some kind of base measurement.

ol1f

It's a fairly large and ugly spot and what you can't see very well are the "Dots" that seem to be inherent in an MT-G2 leds profile.

So I just started raising the reflector, using plastic spacers. I found about the best mix was when the bottom of the reflector was flush with the top of the die face.

ol1g

It's still not pretty, but it did give out the highest lux readings of all the tests. I can still see the "Dots" in the beam and I don't care for the spill much, but it is the brightest spot.

Then I went ahead and put the ring in place.

ol1h

Well, that's much more pleasing to me. The spot is smooth and I'm hardly seeing any "Dots" in it. The spill is just the way I like it.

ol1j

A zoom out shows more of the whole beam and the large, smooth spill from it. I really prefer this to tighter spots, but it's all just a matter of preference.

Ok, what is the collar made of?

ol2a

ol2b

You should know by now...

It's a cut down Maglite AA Incandescent Reflector.

What did I get for lux readings?

These are the 1 meter numbers:

Original with the reflector itself, all the way down as far as it would seat - 6050 lux, according to the meter it read 605 and that's at the X10 lux setting, so it should read 6050 lux

Reflector raised till the bottom of it was flush with the top of the die face - 8000 lux, according to the meter it read 800 and that's at the X10 lux setting, so it should read 8000 lux

The reflector with the "O-L Ring" installed - 6750 lux, according to the meter it read 675 and that's at the X10 lux setting, so it should read 6750 lux

So, it wasn't a success as far as getting a much higher lux reading with this collar, since a focused reflector seemed to get a much higher number, but the overall improvement in the beam profile was really pleasing. I think I may try some more tests with it and maybe put it into a light.

2

Hmmm. The fun and games start, along with the cursing and frustration. Good luck.

3

That’s ingenious Justin.
I never would have thought that a collar like this would have increased intensity.
The beam profile was improved quite nicely, and maybe if some kind of combination of the collar and the reflector sitting higher up would allow higher throw while minimising the loss of lumens (which comes with raising the reflector).

Good work.

4

An attempt on cracking the mysterious Deft X collar? Love it, nice work

5

I *think *something important to figure out is what part of the beam from the LED is used by the reflector to produce the spot… Obviously, light coming out from the top of the LED goes straight out the front of the light without being affected by the reflector so, if this light (contributing to the sidespill) is directed to the reflector before leaving the flashlight, I”m sure lux readings would increase. I’m imagining a reflective dome of some sort just above the LED. In my head, it’s similar to what is used in some single LED lanterns.

From what I’ve seen in the pics, Waiven used a small reflector type thingy to collect the side spill and direct it forward so that the lens can use it as well. With lenses this can work but with reflectors, you have to do the opposite ie, take forward throwing light and direct it sideways to the reflector… Just thinking out loud ok. :slight_smile:

6

Nice work. A home made wavien-type collar for the MT-G2 sounds very interesting. I haven't see any successful diy wavien's for any emitter yet. This is great documentation for anyone that wants to try to take the MT-G2 in the same direction as you are leading in here. Best of luck

7

What the waiven does is redirect the side spill back onto the die surface, since aspheric lights work fundamentally different than reflector lights. The lens acts as a magnifier for the surface brightness of the emitter, they don't depend on actually projecting the photons out the front of the light. Surface brightness in a small area is what makes the aspherics work.

I've used a ring on the MTG2 before similar to the ring on a XRE. Results were mixed, it was in the P60 version and the ring made an improvement, but the overall reflector dimensions just weren't good enough to be something I found usable. In a C8 it's a lot better even though the width:depth ratio is about the same as the P60.

8

i am no expert on optics, but i think the problem here is that the “O-L ring” is a parabolic reflector and the LED is sitting near the focal point of it, and the side spill is reflected back in parallel and hitting the heatsink instead of the LED. like this.

perhaps u can raise the O-L ring a bit so that the LED sits near the center of curvature, then the side spill might reflected back to the LED.

9

The higher I raised it, the more the loss in lux. I thought it might help, but it made it worse.

All the ring is supposed to do is just redirect photons back onto the die, to excite the phosphorus more. Any light that leaves the die face at a wide outward angle would hit the ring and be directed back... Well, it would if I was able to mold a ring with the proper angle of reflection, but since I can't, I just used what I had. It was just to see what would happen.

10

I imagine you could use a small laser to see where the reflector is sending the light.

11

oh, sorry, i forgot one thing, parabolic reflector doesn’t have a center of curvature. but spherical reflector does.

12

I think you might want to try a spherical dome for this instead of a parabolic one…

13

I would say throw an aspheric in front of it. The issue is that the reflector is now blocked partially by the collar.

The aspheric lens may prove to be like a mini wavien, but maybe not…? For curiosity sake I say do it!!

14

Yes, I know, but since there aren’t any except the very expensive Wavien, I went with what I had, just to see. It was just an experiment. I do like the beam profile and I’m not into throwers anyhow. Not really, I only make them because so many others are into lighting up things they can’t identify at a mile away.Wink I think that as is, it gives a nice beam in this reflector, which would work well in a D Maglite.

15

I’ve tried an aspheric on an MT-G2 and you get a bunch of dots in it, due to the surface of the die. The rough surface gives a bunch of bright and dim spots all through it. Not very appealing. possibly a small lens to pre-focus, close to the die and then a large aspheric might work. Maybe someone will try that.

16

Maybe you could find some small silvered plastic spheres at a craft store or something like a christmas tree ornament you could cut up?

17

Those minimag reflectors(not the led ones) appear more spherical than parabolic anyway but the results sure speak volumes.

18

This sounds good. What do the dots look like and do they do weird things?

19

There’s an idea. I have been to craft stores, but didn’t look at xmas stuff.

20

I did this search on Ebay:
http://www.ebay.com/sch/i.html?\_sacat=0&\_from=R40&\_nkw=acrylic+silver+balls&\_lncat=0&\_arm=1&\_armm=94&\_ruu=http%3A%2F%2Fwww.ebay.com%2Fsch%2FHome-Arts-Crafts-%2F160667%2Fi.html%3F_from%3DR40%26_nkw%3Dacrylic%2Bsilver%2Bballs%26_arr%3D1&\_armi=Home+Arts+%26+Crafts

A couple of likely suspects popped up:
http://www.ebay.com/itm/20-PCs-Silver-Tone-Smooth-Ball-Spacer-Beads-Findings-19mm-Dia-/130961390282?pt=Craft_Beads&hash=item1e7de83aca

That was just in one category…