Converting 3D Mag into 4C - questions

[etc]

I have a 3D Mag I will be converting to 4C. It has the Malkoff module.



Questions, where do I get the 1" PVC pipe, is that a standard size that fits well into D sized Mags and holds C cells without them being loose inside?

And what's the length to cut it to?

Why do you have to invert the spring in the tailcap?

 

[Supernam]

PVC at any hardware store. 7 1/4". Roll up a little bit of printer paper if you want to make it snug with the mag body, don't make it too tight, you might want to be able to take it out if you want. You can invert the spring, but this might put too much pressure on the cells. I prefer cutting the wide part of the spring, or what I did was I purchased a conical spring at the hardware store that fit inside the tailcap. You have to strip the anodizing inside the tailcap of course.

 

[FILIPPO]

yes you must recess the spring in the tailcap to fit 4Cs....

and I also think a PVC tube is the best way to fit them in a "D" body

:thumbsup:

 

[etc]

what's the best way to do that?

quote:
You have to strip the anodizing inside the tailcap of course.

 

[Supernam]

Dremel.

 

[warlord]

I did a 2d to 3C on a silver mag and there was no anodizing on the inside of the tailcap, it worked fine without any dremeling. On my red mag I did have to use a dremel. Just FYI, it might save you some time if you have a silver mag.

 

[etc]

I have the dremmel tool, which bit do I use?

Is the idea to take off the surface layer, that's it?

 

[Al Combs]

what's the best way to do that?

quote:
You have to strip the anodizing inside the tailcap of course.

Oven cleaner will strip anodizing if you have some handy. It creates a surface that looks like it was sandblasted in 10 or 15 minutes. If you have the type in a spray can, put it in a cup first. Then pour it into the tailcap. There will be no damage to the outside finish that way. Rinse thoroughly with running water (carefully) when finished.

 

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I just tried sticking 4C cells into the 3D MagLED (the stock 3W one) and it worked just fine, with just the spring reversed.

Apparently it's making enough contact - is that the key concern here?

I do have oven cleaner, will it result in better contact?

 

[warlord]

No, it's just another way to strip the anodizing off. I used a little oven cleaner then I rinsed it out and polished the bottom usining a dremel polishing attachment. Alternately you can just use one of the grinding bits.


The point is to make sure you have good contact between the spring and bare metal. If you don't have good contact the flashlight won't work or may only work intermittently.

 

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What I don't understand is why it wouldn't make contact with the spring reversed, when it had good contact with the spring in default position.

I reversed the spring and it made good contact without me stripping the finish off the inside the tail cap. Apparently anyway as I didn't test it extensively.

The cells were alkaline and fully charged at 1.55V.

 

[Supernam]

You strip the anodizing off IF you cut your stock spring to fit inside of the tailcap, or if you use a smaller spring that sits inside of the tailcap where it is anodized. When you use a stock spring in reverse, the wide part of the spring makes contact with the tailcap in the same spot it would in the original configuration.

 

[etc]

OK, thanks for the help.

I used "Drano" to strip the anodizing. Works pretty well in 15 minutes. I finished the remains with some fine sandpaper. Good stuff.

Where do I get a spring that fits well, better than the reversed stock one?

Or can I get another stock one and just cut it to the right length?

I haven't noticed any improvement with 4xC alkalines but I suspect that 4xC NiMH will make a difference...

 

[etc]

I did it and it works well.

A few observations:

Light is much lighter. 4xC cells weight about 1/2 of 3xD cells. Also the capacity is about 1/2 of D cells and I would think run time is greatly reduced.

 

[2xTrinity]

Last time I tried to fit 4C cells in a 3D mag, I went down to the local Fry's and bought a special tube that is custom fit to hold 4C cells -- it's called a "4C maglite", and cost around $18.

 

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The search on frys web site does not reveal anything like that.