2 C mag 3x123 kpr 112 = WOW

TOB9595 · Jun 6, 2003

I'm sorta snipping from the bigger thread as it'll be easier for many folk to see /ubbthreads/images/graemlins/smile.gif
I got the info on 2C mag with 3 123 batts, and a radio shack KPR 112 from this megathread 285 lumen mag
This is a killer light. I used 3/4 nsf pipe to contain the 123's.
Real easy to do! a 10 foot length was ~ $2 at Home depot.
I, among many, am looking forward to my carley, and probably WA, bulbs to really get this cooking /ubbthreads/images/graemlins/smile.gif
Tom

Ginseng · Jun 6, 2003

Hmm,

CA809 + 4x213 = 325 lumens. /ubbthreads/images/graemlins/ooo.gif Yeah, I think I can deal with it. /ubbthreads/images/graemlins/grin.gif

Wilkey

PaulW · Jun 6, 2003

Wilkey,
Hi. I had an idea about the Carley 809 bulb mod. Instead of posting it here I'll put it in the "285" thread.

TOB9595,
I did some measurements about a month ago. I found that the KPR-112 mod is 3/4 as bright (approximated lumens, using reflectd light readings) as the Space Needle II. But it throws much better -- more than twice the lux measurement at beam center. Great for illuminating small targets like house numbers and street signs. Yup, you get a lot of bang for the buck in this very easy mod.

Paul

PlayboyJoeShmoe · Jun 6, 2003

It's kind of funny strange. But I have a 3D M*g with 4Cs driving a 3.6V bulb (probably stock M*g whitestar - but could be Rayovac) that comes in second to my Space Needle for white and bright. It has writeright just as my 3-123/KPR112 light has and kicks it's butt by a little bit.

Now THERE is a cheap mod! (Kind of a big light though...)

Kill-O-Zap · Jun 6, 2003

I've been following the monster 2C/285 thread and was a little overwhelmed by all the options, plus the really interesting ones were the 4x123 options with the ugly tailcap/spring issue. I ended up passing on the group buy. Now here's one option that I can try out any time because the 112 is readily available. But before I run out to buy the 2C, can anyone answer these questions:

- What would be the (approximate) lumen output with this mod? (3x123, KPR112)
- How overdriven would this bulb be, and therefore what kind of life can I expect? I imagine the bulb is cheap, but if I'm changing it every 10min, that could get annoying pretty quick.

Thanks!

PaulW · Jun 7, 2003

Kill-O-Zap,

I estimate the KPR-112 mod at 100 lumens based on light-meter comparison with my M3 with HOLA (225 lumens advertised). At beam center it was brighter than the M3, but the KPR-112 in Mag 2C has a very little spot. The M3 spreads its light over a large area.

The KPR-112 is spec'd at 6 volts, 0.75 Amps. When I connected it to 3 fresh 123s it drew 0.80 Amps, sucking the voltage down to 8.5 volts. I never had one flash on me using this implementation. I suspect that it is designed to be more overdriven than the commercial bulbs from Carley or Welch Allyn.

Have fun with the mod. /ubbthreads/images/graemlins/smile.gif

Paul

TOB9595 · Jun 7, 2003

ANNNNDD, the kpr 112 is $1.29 each at Radio Shack.
KilloZap,
This is a MUST mod. You will be so pleased. It's small, light ((weight)pun)) and bright /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif
I can see this as my fav walk the dog in the dark fields light.
The darker the better /ubbthreads/images/graemlins/smile.gif
Home depot will cut the pipe to fit in the car too.
And I recommend Chris's ucl lens @ flashlightlens.com. Visit him in Dealers forum I think.
NEXT a group buy on 2 and 3 c mags. YEAH!!
Cheapest I can find is ~ $15 @ Home Depot.
Tom

Ginseng · Jun 7, 2003

I found a leftover 2C at Sports Authority for $12.97. But they only had one. I have never, ever, seen a Mag 3C at retail and I've looked at any place I can think of in RI. The cheapest I've found Mags online are at ZBattery.com. Good service, good prices. They carry the entire Mag line from 2C to 6C. 2C: $15.70, 3C: $17.89, 4C: $16.94, 5C: $24.00, 6C: $25.00. Strangely, the 3C costs more than the 4C /ubbthreads/images/graemlins/icon3.gif

PlayboyJoe,

I think the reason your 3-cell bulb in a 4 cell setup is so bright is the percentage overdrive is higher than 3x123 driving a 5-cell bulb. 133% vs 120%

Kill-Zap,

I've played with my KPR alot and it has not flashed...intermittent and continuous use. As for throw, it's tremendous. It is nice for walking around outside cuz the spill light is pretty bright. I second the light output estimate. It's slightly less than my 5W V-bin which is rated for around 150 lumens max.

Wilkey

Kill-O-Zap · Jun 7, 2003

Ok, I'm convinced. Thanks, guys.

hideo · Jun 7, 2003

it's a great cheap drop-in ... now I'm chomping at the bit to do the 20W MR 16 5x2 123 mod in my Mag 3D /ubbthreads/images/graemlins/wink.gif

hideo

hideo · Jun 7, 2003

question? how have people dealt with the overtorqued spring sliding off to the side of the 123s when the rear cap is screwed down??

I halved the spring as someone suggested and it is still too much--I'm using the polyfoam wrap on the batteries which may be part of the problem ... better luck woth PVC battery sleeve?

hideo

PaulW · Jun 7, 2003

Yes, I think using the PVC will solve your problem. It's more work, but the end result is nice. I bought the PVC in its smallest length (10 feet) and immediately cut it in half to get into the car. I cut the PVC with a fine-bladed hacksaw, although you could use anything. Cut it to a length about 1/4 inch shorter than the 123 battery stack. Remove burrs with a fine file. Then wrap with duct tape until, when you put the PVC tube in the body, it has just a little resistance to sliding. For my roll of tape, that was 29 inches worth. Pictures and further good ideas by Ginseng are here.

What did I do with all the left-over PVC? I made battery carriers -- holding 1, 2, 3, 4, or 5 batteries each. I just slide 25 cent end caps over each end, and I have a snug tube to throw in my glove compartment or suitcase.

P.S. On that 20W mod, I'd like to hear how you handle the reflector melting issue.

hideo · Jun 7, 2003

Paul-- thanks for the tip--think I may even have some in the right diameter leftover from a plumbing project--the caps are great for poor man's fishing rod cases, etc.

the MR-16 bulbs have integral reflectors that can obviously handle gobs of heat--

thread is here--might have to make some neoprene washers

MR-16 3D Maglite Mod Finished!

soloco's page link on the mod is in the thread

wish I could figure out how to drill the filament out to use the reflector with LEDs

hideo

Ginseng · Jun 7, 2003

Hideo,

You might want to get a hold of a burnt out Tigerlight lamp assembly. The potted bi-pin bulb is easy to remove and the aluminum reflector can be cut with a file or a fine toothed hack saw. And it fits perfectly into the front bezel of a Mag C or D.

Wilkey

TOB9595 · Jun 8, 2003

Ginseng, I truly love the copper battery blanker . Home Depot Here I come.
Also is there any use for the KPR 118? in these configurations.

cmendoza · Jun 8, 2003

Anyone have an estimate of the runtime?

PaulW · Jun 8, 2003

Run-time estimate:
It's kind-of inversely proportional to current (no relationship to the number of cells). I measured the current at 800 mA. Comparing it to the E2e's 1130 mA which gives 65 to 75 minutes, and the SL Scorpion's 1220 mA which gives about 60 minutes, my rough guess for the 3x123kpr112 would be 90 to 100 minutes.

Ginseng · Jun 8, 2003

TOB9595,

You can certainly try the 7.2V KPR118. Due to its reduced overdrvive, it is not visibly any brighter than the KPR112.

Wilkey

PlayboyJoeShmoe · Jun 8, 2003

Could you possibly have meant 33% and 20% when telling me why my 4cells on a 3cell bulb is so bright?

I have figured it this way... 3cells driving 2cell is 33% over (and I have had some trouble getting bulbs to last). 4cells driving 3cell is 25% (and less but still some trouble). 5cells driving 4cell 20% and so on (and haven't yet cooked a bulb with 5, 6 or 7 C cells driving a one less cell bulb). I figure it gets safer with every step up.

Please correct me if I'm wrong...

PaulW · Jun 9, 2003

PJS,

I'll take a crack at answering your question about what Wilkey said. He's probably in bed by now.

<ul type="square">[*]4 cells driving a 3 cell light is 6 volts instead of 4.5 volts.
[*]The ratio is 6 / 4.5 = 1.33 = 133%.
[*]100% = normal drive.
[*]133% = 33% above normal drive = 33% overdrive,.
[/list]
Yes, it gets safer with each step up.

Paul

2 C mag 3x123 kpr 112 = WOW

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