2-D to 1-18650?

louie

Flashlight Enthusiast
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I'm not up on the latest here, I'm thinking of converting a couple of old 2-D M*glites to something a little more useful, like the Firefly PR drop-in and I'd was thinking of an adapter to use one 18650 since I have plenty of them, they are fine for my use and a little safer in single cell config. But I don't see them at Lumencraft. Does someone make a decent adapter tube at reasonable cost? I'd rather not do Aliexpress and the like. Or do folks just use plastic pipe or somesuch?
 
I 3D print adapters to use button top 18650's in 2 and 3 C and D cell Mags. For the 2D I use a adapter (red) to convert the 2D to 2C and a adapter (blue) to convert 2C to button top 18650.

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Shoot me a private message if you are interested.
 
I think I saw those on that other forum, an interesting solution.
I think I'd still like to hunt around the Home Depot plastic pipe department first.
 
I think I'd still like to hunt around the Home Depot plastic pipe department first.
Why not use the 21700 or 26650 with more capacity and more run time per charge?
Also possible to use 2x26650 (7.4 Volt) in 2D M*g with sleeve adapter and modified tail cap.
 
Only that I already have 18650s and didn't really think I'd also get the larger cells. Not really looking for a monster light, just a modest way to get a useable light out of a useless one, at minimal cost.
 
26650 is easier, you don't really need a spacer if just using a single cell.

I have an AA to D cell adapter with an AA blank in. Put this in first, as it will make contact with the small positive spring contact in the Maglite 2D. Then a 26650, align it with the spring on the tailcap and screw the cap on.

I suspect an 18650 would work, but more likely to wobble about the negative terminal of the battery is smaller to make contact with the tail spring.

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I may have to rethink. It would be easy to just buy a couple of 26650s, an adapter tube, and PR dropin, and in one stop.

I need to see if any of the PR dropins are high-CRI.
 
I currently run an 18650 in a 3D Maglite, and a 26650 in another 3D mag.

Get PVC pipe that fits an 18650, cut it the length of a 2D body, some Gorilla tape around the ends to center in the tube.

Here's one of my setups I used to run 2 CR123's. It's got plain electrical tape around the PVC pipe, and also the aluminum rod spacer. However, electrical tape stretches and deforms over time, so I recommend Gorilla tape now, it's a little more stable.

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Instead of an aluminum rod, I've been using a plain dowel with a piece of wire attached at each end for less resistance.
 
I use rolled up printer paper with some super glue in my modded work maglites. Battery spacer can be aluminum rod, or a piece of wood with some copper wire through it. It´s done in minutes and works. Maybe a coin or washer between spring and battery.
 
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1 inch pvc is a perfect spacer for D to C, tried it many times in maglites. now from C to 18650 3/4 pvc would be a match but it is 1/100 of a inch larger than inside of 1 inch. it would not go in, but i do have an idea, if i cut 3/4in along i may be able to squeeze it ,and inserted into 1 inch pvc, that would make perfect D to 18650 spacer. i will try it in the next few days, and report.
 
That pipe mod would be good to know.
I'm disappointed that none of the simple, affordable LED drop-ins seem to be high CRI, or easily moddable to a Nichia 219. One of the Mags here needing the battery adapters already has an old LED mod - the hotlips insert, 1A Downboy converter, and it used to have an SSC P4. I just replaced that with a kludged Nichia 219B 9080, and it looks quite useable. Currently using an old Modamag 6AA to 2D adapter which works fine, but the springs seem to be weakening and I would like options. The other Mag 2D is completely stock.
 
1 inch pvc is a perfect spacer for D to C, tried it many times in maglites. now from C to 18650 3/4 pvc would be a match but it is 1/100 of a inch larger than inside of 1 inch. it would not go in, but i do have an idea, if i cut 3/4in along i may be able to squeeze it ,and inserted into 1 inch pvc, that would make perfect D to 18650 spacer. i will try it in the next few days, and report.
That pipe mod would be good to know.
the results are in. it works so far. i used Dremel spiral saw, the only thing i had available at the time, it would not cut straight at all, but it did not matter. it made it possible to squeeze 3/4 pipe inside 1 inch pipe, internal diameter measures 19mm, which is pretty good fit for 18mm cells, but i've yet to try actual cells, when i get home i try'll several brands. It is not a lightweight, 2 feet mod weights 1.10 lb, or 500gr. it could be made lighter, by drilling large holes across using a hole saw.
Edit; tested it with panasonic protected(double wrapper), efest, and LG, all go in easy and fall out freely, so it is now tested and working mod.
 

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Good to know. Is there a spec for that particular pipe, or are they all the same diameters for generic PVC pipe?

For 1/100 inch difference, I wonder if you could just sand the inner pipe down. Put it in a lathe.

2-D size won't be 2 feet long...
 
Good to know. Is there a spec for that particular pipe, or are they all the same diameters for generic PVC pipe?

For 1/100 inch difference, I wonder if you could just sand the inner pipe down. Put it in a lathe.

2-D size won't be 2 feet long...


I do not have a lathe, but yea it could be done that way too, there are many ways it could be done.
 
My Home Depot claimed they no longer had 2 ft. lengths of PVC, despite the website showing 40 in stock. Just 10 ft.
 
they are usually on a wheeled rack in the plumbing pipe aisle, where 10 footers are sold, several times i had the same issue, with other items, it shows in stock but the workers say they do not have it. I end up finding it anyway, someplace else. Those folks are not really much help half the times. their hiring standards or training, or level of care are way too low these days.
 
Yeah, eventually I'll go back with the stock printout. Or just buy 10 feet, the cost per foot is better!
 
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