chipping a light down??

okay… so I make infrared illuminators…

i have coppped a light down before? but… since my driver was a 12v driver (same power requirement as camera…) it made sense, t just send 2 power wires over from the camera power, to the light… i just whacked off the head of the light, and ran the power wires up in and soldered them in place (power to positive, neg to body of tube)

so… whats the basic go-to strategy if i want to chop, say… a 3D flashlight down to take a single 18650 ?? I realize you guys with the metal lathes show off how you cut it into sections, and cut threads… i dont have a lathe yet, so, thats not an option…

any simpler home strategies? I would like to be able to retain the stock tail end…

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i was thinking, of just cutting out the appropriate sized section from the middle, and since i am going from D cell to 18650? trying to find appropriate sized plastic tube, tight fit… and then jbweld the thing together…

the tube would be the battery diameter rducer, and the “thing” that tightly coupled the pieces together… and i figured jb weld would hold it all together…

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any better strategies?

When not using a lathe you pretty much nailed it. I would suggest a metal tube but other than that that’s pretty much THE process.

and i thought “best i could come up with on short notice” was sort of ghetto, lol…

had no idea it was recommended practice! (lol)

I once chopped a Roche F12 1x18650 battery tube down to 1x18350 size.

I sawed it into 3 sections using a handheld hacksaw. Then removed the middle section and polished the 2 remaining threaded sections. I used a pin-vice drill and a very small drill bit to drill a couple vertical holes on each edge of the remaining sections. Then I inserted 2 small brass rods into those holes. These rods keep the 2 sections aligned.

To stick them permanently together I initially tried spreading lots of low temp solder paste and flux into the join, then pressing the 2 pieces together and baking the hole thing in the kitchen oven. That didn’t work well…. aluminum is very hard to solder.

I then resorted to Super Glue gel. I’ve had the light in this form for over a year now and it hasn’t fallen apart yet. Not sure I’d trust it to hold together if I dropped it onto concrete though.

Instead of super-glue gel, a better way to make the join would probably be some aluminum brazing rods and a blowtorch. Then once the join is complete, file it down until it looks halfway decent. or get some proper aluminum solder and flux.

Without a lathe I’m not sure it’s possible to cut fresh threads, so your only option is to do something like I did: cut out the center section and stick the 2 end sections together. For a 3d light, you might be able to insert an internal tube (perhaps out of a piece of rolled up sheet metal) to hold the pieces together. This should work so long as the new battery is narrower than the light’s original batteries.