Hi all. This is my first mod of a flashlight and hopefully not last.
It was a group effort, my dad, my brother-in-law and yours truly. A nice Saturday evening of beer, chit chat and fun with flashlights. :)
We upgraded my dad's old Maglite 4D with a 5x XR-E R2 Drop-in Module from DX.
(Use this referral link to buy it, if you like my thread and want DX to give me some points.)
Since he didn't want to work with Li-Ion cells, we decided to keep his maglite on regular D cells. The drop-in I linked above works quite fine with 4 D cells.
We did not swap the stock switch, nor pretty much anything else. Most of the work was modding the maglite parts to make the drop-in fit.
If you are reading this you probably know how a stock Maglite D head looks like. Unscrew it and take out the stock reflector. Put the lens somewhere safe while working, you'll need to use them later.
Next, try to fit in the drop-in. You'll see that it doesn't fit. Either the drop-in or the stock maglite head needs to be modded. Wo chose to scrape off the excess material from the head. I somehow feel that shaving off the aluminum fins of the drop-in would do more harm to the drop-in than modding the head.
We used a drill bit that literally scrapes of stuff you put under it. Google says that's called deburring drill bit. My dad had one or two old ones, very similar to this one this one. His were VERY sharp and made of what looked like some very hard steel. Having the drill in the drill stand and holding (and moving) the mag head with the drill being in a fixed position is the way to go here.
Take care not to take off too much material off the head, rather scrape off little by little and check how the drop-in fits every few millimeters. Once you are satisfied the drop-in fits, leave the head and take care of the drop-in.
The original drop-in has two spring coils:
Next, unsolder both original coils.
Then solder a new positive contact that is thin enough to go into the stock Maglite bulb base/holder without coming to near the negative base contact. But be careful to make it thick and firm enough so it doesn't ever bend. I used a brass screw.
Assemble the new head, use your original lens, or swap with better lens.
This is the stock maglite bulb base. It moves up and down on it's own spring. Additionally, the center positive contact has it's own, separate spring. The positive contact is not visible on the picture, it's at the bottom of the threaded tube that you can see below. The screw I soldered to the positive contact of the drop-in will touch the positive contact of the base, but must NEVER touch the negative contact (threaded tube). That's why it has to be firm/rigid and not bendable. A really thick copper wire or a brass screw soldered to the drop-in center contact is perfect for this.
Next up, making the "adapter" for the negative contact. Stock maglite bulb base is too narrow for this dropin for my comfort. I never want it going near the center drop-in contact so I want to make it wider and at the same time keep it away from the positive contact.
Take some thick copper wire, a washer and make it! :)
Washer should be brass or copper so you can easily solder onto it. See below. Lacking a brass washer of the proper size we used a steel washer. Soldering was a bit problematic, but it turned out fine.
Inner diameter should be exactly the outer diameter of the maglite bulb holder tube, but without the threads, threads excluded. This washer must fit outside the bulb tube, but also must be stopped by the tube threads, not go over them. Outer diameter must be within few millimeters of the drop-in negative contacts, or roughly the diameter of the original large spring coil.
Take a piece of copper wire, roughly 2-3 millimeter thick and bend it into a ring shape.
Here is melting the solder so the copper wire will fall level with the washer. Here the washer is standing on another piece of metal, just so it doesn't stand on the wooden surface while I'm melting the solder with a gas torch.
Wire ring soldered to the washer.
Scrape off the solder dirt. Literally, it's dirt at this stage. You want this to be clean and corrosion free.
Put it onto the stock maglite bulb tube.
And carefully screw on the maglite head. Do NOT tighten too hard.
Here is the first problem we ran into. The maglite head doesn't screw far enough to cover the original head rubber o-ring. See picture.
Not to worry, we can modify the washer adapter. Grind off some material. Or use thinner wire to begin with. ;)
Unfortunately, while it helped, this still wasnt enough. Head still didn't comfortably cover the rubber o-ring.
I didn't want to grind off more material not to get too close to the center contact on the drop-in.
Not to worry, let's mod the stock bulb base.
Use whatever tool is at your disposal to cut off the plastic black tube that is around the brass maglite bulb tube. See pic. We used a miniature drill bit with a saw disc at it's top.
See the difference? The black part is much lower now. Try the mouseover on the pic above. Mouseover isn't perfect but you can clearly see the black tube is now shorter.
As you can see, the head now screws over the o-ring.
Unfortunately, after I got home I realized that I had no "money shot" of the drop-in through the lens. I'll have to correct that first opportunity I get!
Finally, here is a beamshot of the completed upgrade. I don't have the "before" beamshot, but trust me, it would be much less visible than that yellow streetlight in the distance.
This beamshot is some 12 meters away. About 40 feet. This wasn't in the absolute dark, you can see the yellow shadows from the streetlights across the street.
The funny thing is, his set of D batteries were more than a year old, cheapest supermarket non-alkaline version you can imagine. Used numerous times with the incan bulb. A year in the mag, inside the car. With temperatures from -10C in the winter to +60C in the summer sun.
Literally, there was no difference between the high and middle mode. :)
Which means, this was really poor amount of light compared to what a fresh set of batteries would give. The spot intensity was close to the intensity of my DRY NW at the same distance. Though DRY did cover almost the whole visible wall with the same intensity.
All this was measured by the very scientific "use your eyeballs" method.
After he gets some fresh batteries I expect I'll take more beamshots and post updates to this thread.
This covers most of the Mag LED upgrade. I hope you like it and at least someone finds it useful.
If there are any questions, I'd be happy to answer as best as I can.