My MR16 Mag Mods (with many pics)

Hi all,

Well, I borrowed a digital camera from a buddy of mine. So, in between the hustle and bustle of the holiday season, I have taken a few picks of my meager flashlight mods. First up, a couple of 20W 12V MR16 based Mags. (Pics link to larger versions)



These are *really* simple mods to do. The lights themselves remain bone stock, so you can use them as they where before. (Why you would want to do this, I'm not sure. /ubbthreads/images/graemlins/tongue.gif )

I made my PR base adapters in a similar manner as documented HERE by Chief_Wiggum. There are a few differences though. The pin recepticles I used have a plated, fully enclosed body and gold (I think) contacts internally. For the negative recepticle I soldered directly to the PR bulb base. Also, I did not completly remove the base material. I left the glass like tail on the bulb and made use of the factory positive contact area.




After trimming down the positive wire a bit of solder is added for a PR base that looks stock from the back and has JB Weld potted pin recepticles on the front. The adapter is inserted into the lamp just like a regular bulb. The assembly order of the head components differs slightly. The main head must be screwed on, then the MR16 bulb inserted. Lastly, the lense bezel is screwed into place.



The bulbs I used are the Osram 12V 20W MR16s available at Lowes. They come packed individually and are labled "narrow spot" IIRC. There was a three-pack of similar bulbs available that I almost purchased, until I noticed that they are not as narrow a spot and they have a shorter stated lifetime. I bought a 50W spot from Home Depot. I was very disapointed in the quality and the output so I didn't finish the 2x7x123 4D Mag I was going to put it in.

The 4D in the pics is powered by 14 E2 Lithium AAs. The 4C is powered by 7 SF 123s. The SF C3 was the brightest light I owned until I made these mods. I included it in the beamshot for refence. The order l-r is C3->7x123->14xAA.



Some notes about the beamshot. I couldn't figure out how to set a fixed exposure level with the borrowed camera. So, individual shots of each of the beams would be useless. The picture above was taken on the ceiling of my livingroom with the lights on. These lights are pretty dang bright and have a HUGE, usable sidespill. All you can see in the pic is the hotspot of each beam. Curiously, the hotspot of the 7x123 is a bit larger than that of the 14xAA. At first I thought it was symtom of reflector variances but, after switching them, it apears to be a fuction of the driving voltage/amperage. (The wide spot doesn't follow the bulb.) While it's a bit hard to see in the picture, the 14xAA is a little brighter/whiter that the 7x123.

I really like the 7x123 in the 4C Mag. It has become my favorite light to grab when I know I'm gonna' need one. I still don't have any runtime data. I did run 7x123 down to competely empty but, I did it on accident and wasn't there to see it. /ubbthreads/images/graemlins/banghead.gif I guess that means heat isn't an issue! /ubbthreads/images/graemlins/grin.gif I keep thinking I forgot somthing... Oh well, I can always add later. If I get a chance, I'll post my first real LED mod later. (well, simple, but real.)

Thanks again to all,
See ya'

Wow, very descriptive post! Any idea on runtime? I took a look at those bulbs, they have glass reflectors. Im guessing they wouldnt take the slightest bump or drop very well... Any chance of getting some outdoor beamshots? Nice job!

Super nice work DG. I don't know how you were able to do your soldering inside the PR base with those fat leads. I was using thin wires and was tearing my hair out.

Wilkey

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MTFD17 said:
I took a look at those bulbs, they have glass reflectors. Im guessing they wouldnt take the slightest bump or drop very well...

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Was thinking about that too. Maybe, if there is a little bit of space left between the MR16 and the Maglite lens cap, a rubber or neopreen collar could be put there for increased shock resistance?...

Hi guys, Thanks for the kind words.

MTFD17,
I might just have to bite the bullet and turn the 7x123 on and time it. Only problem is that without a light meter the results of the test would be purely subjective. (Like how long to %50 brightness etc. ) About the only thing I could comment on is "usable" light time. Good point BTW about the durability of the lamp reflector. I'm usually pretty nice to my equipment (my Jeep excluded). Most of my flashlight duties are camping, four wheeling, bump-in-the-night type stuff these days. Not the most demanding of environments. I have dropped the 7x123 twice though, so I know it will survive a bit of "casual abuse". The last one was when it rolled off the kitchen counter while I was taking the pictures above. As for the outdoor beamshots, I'll see what I can do.

Ginseng,
I actually went to the larger wire because it was easier. In the way I did it there wasn't really any lead soldering done *inside* the base. The first solder point was the negative pin receptacle and it doesn't have a lead. I just grabbed the lip of the base with lock-jaw pliers, placed the receptacle inside and dropped a small piece of solder next to it. I then heated the whole darn thing up until the solder melted, securing the receptacle directly to the body of the base. For the positive receptacle I soldered the lead and shrink wrapped it on the bench, then just dropped the lead through the hole in the center of the base. The thicker wire helped me to hold it in the correct place when oozing in the JB Weld...

Ingenious! I guess that's why I'm a chemical and not a mechanical engineer. /ubbthreads/images/graemlins/grin.gif

Wilkey

Hmm, I don't know if these will help (or amuse) you guys much but here's a couple of shots outdoors. I don't know the exact distance but I would say it's ~100 feet to the trucks across the street.

The 14xAA MR16:


and the Sure Fire C3 (with P90 bulb) for comparison...


My subjective opinion: This camera sucks for doing individual flashlight beamshots. Without the ability to fix the exposure characteristics there is no meaningful relationship between shots... That being said. I think both shots look darker than they did to the eye, but relative to each other they seem pretty close.

Nice pics. It seems to throw a pretty good spot, although not lazerlike. Good color rendition.

Wilkey