(image heavy) MagLite 455, 1.8mA @ 1.xW preserving internals

[thinksnow]

(title wrong, obviously- it's a 445, not 455)

Using jayrob’s thread as inspiration, I made a 2-D cell MagLite conversion that preserved the innards, in case I ever wanted to change it back.

First, a bunch of links that made this all possible:
• DTR's M140 in diode w/ glass lens
• Mohgasm C6 host (black w/ pill not in stock at time of writing)
• Mohgasm linear driver
• Mohgasm C6 heatsink
• Mohgasm wires and shrink
• DTR’s tutorials

All the parts laid out

So, two things wrong with this build:
1) I bought a regular driver, not a boost driver, and the host only supports 1x18650 (whoops).
2) The host doesn’t really have enough room between the sink and the pill for the driver, so I drilled it out and used a dime! It press-fit perfectly with just the slightest help from my vice.
(idea completely stolen from DTR)

Note the hole I drilled in the dime, planning ahead for the positive lead, and the felt (re-purposed couch-feet sliders)

The felt is used as an isolator for the positive contact:

Next, soldering the leads:

And connecting the diode to the driver:

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So, this was all good, but without an extension tube for the C6 ($20!), this host wasn't going to work. And I'd already seen jayrob's MagLite thread, so I went about moving things. I used to build computers pretty often, so I knew I had materials laying around that would make a very serviceable heatsink, so it was just a matter of figuring out how to put it all together.

What isn’t shown was using a 15/32” bit on my drill-press to drill a 11.9mm hole, but you can figure that out easily enough.

Measuring the diameter for the heatsink using some left over flooring as the template:

Rough-cutting the sink, squaring it up:

Fins to the left, fins to the right:

Rounding the sink. I debated cleaning it up a little more, smoothing things but, since this is for me and not for sale, and since it’s really never going to be seen inside the host, there really wasn’t any reason to:

And checking for fit:

Now, just a little polish for the part that is going to be visible:

The key to this is that I had a dead LED bulb that I realized I could re-purpose, which would allow me to leave the MagLite intact for this build.
Reusing the bulb:

Steel wool to ensure positive contact inside the plastic portion:

Another thing I didn’t get shots of, was the tail-cap spring. I cut ~1/2” off the normal working end and then flipped the whole thing over, so the part that is normally in the tail-cap is now the part that is making contact with the batteries.
That step and re-using a dead LED blub housing both ensure that I can easily re-convert this host back to a working flashlight if I ever choose to.
And there you have it!

Measuring a D-cell to make a sleeve, and the sleeve:

And now…beam shots!
This is pointing out to the woods about 100’-150’ through my back yard. The green is a (supposedly) 5mA DX 532nm (SD-230)

And this is lighting up a tennis ball from 2’ (and leaving scorch marks almost immediately)

 

[Laik]

Nice build. +1

 

[thinksnow]

Thank you. Since the bulb re-use is, in my mind, a main feature of the build (together with the CPU heatsinking), I'll make sure to add some pictures of the internals soon for any interested parties.

Something odd that has happened twice now: whenever I have the beam on for extended periods, say > 1 minute, it will begin pulsing on and off at the rate of about 2 seconds off, 10 on.

This happened the night I was taking the beam-shot photos, and again today while I was popping a few balloons in the basement (wife and daughter are away for the weekend, so I can play...er, experiment... without worrying about bystanders).

In both instances, the heatsink was room temperature, certainly not displaying any elevated temperature. I didn't check the driver, but don't know if that would do it.

Odd.

 

[Speedy78]

Frankestein build! Nice ingenuity! I cant imagine cutting fins on a heatsink was any fun.

 

[Laik]

I think it could be the driver overheating.

 

[Speedy78]

Do your batteries have a protection circuit?

 

[TheDukeAnumber1]

Improvised builds like this are my favorite. Nice build.

 

[thinksnow]

I will try snugging the driver up to the heatsink, or to the side wall of the upper section of the host, to see if that helps heat dissipation.

As for the batteries, I guess I'm not sure. They were pulled from my wifes old laptop battery set and you can see one of them in the topmost photo (Found an image online, too, which says "unprotected," so I guess that's that.)
All readings appear fine on the old analog multimeter.

 

[grainde]

Great work! I really like the heat sink its very inventive. If you ever wanted to mod a mag light, with a fan and tec, this would be perfect to enable an airflow past the heat sink! +1 and :beer:

 

[thinksnow]

Ha! I had thought about using a VPU/north bridge fan internally, but there is so little heat so far, I can't justify it.
(and thank you)


Also: the "checking for fit" shows a number of bent fins, but I straightened those out before final fitting.