I've seen posts on how a nitrolon Surefire G2 can't be bored like the aluminum cousins 6p and 9p because of the metal sleeve used in the G2. After looking at the light, I didn't see any reason why it can't be bored, as long as the sleeve is retained and expanded. I took some photos along the way. I am by no means an expert at this and there may very well be better ways to do this, I was just curious and used what I had around the house. Don't try this at home, it was just for fun. It took me ~6 hours, just buy a bored 6p and save yourself the trouble. I am not able to post attachments, so these photos are hosted on my site. Click on them to get a larger version for a closer look.
I used common hacksaw to cut through the sleeve inside the light. Take the saw off, feed through the body of the light. I wrapped the light in painters tape so I can clamp it down lightly.
Start cutting the sleeve from the inside. I found that with my sloppy technique, the ends were cut first, so I took it slow and tried to cut evenly, only through the metal sleeve.
Once the sleeve is cut, it is easy to remove with a pair of needle nose pliers. It is just press-fit into the body, there was no adhesive of any kind. We need to save the sleeve, so be careful and take it out. Note that there are 2 different lips on the tail and head ends of the sleeve.
I obviously did a poor job here and cut into the body, but we're going to bore that part out, so no harm done.
The 18650 will be riding inside this sleeve, so I used a file to take off the rough edges in the cut and used 220 grit sandpaper to make the inside edge of the cut very smooth and dull, so as not to cut through the insulation on the 18650.
Then I used a trick I saw on youtube where someone was boring a 6p. I built up a duct tape plug on my 1/2 inch drill bit and then taped 80 grit paper to it. Using the drill I was able to quickly bore out the body to match my 18650, an EagTac 3400mAh. Because I could not use the battery for fit, since the metal sleeve will have to go back it, I built up a 1mm sleeve on the battery with painters tape to account for the 0.5mm thick metal sleeve, plus a little extra for an easy fit. I found here that sanding too quickly will get the G2 body hot and will melt gobs of plastic to the sandpaper, so take it slow. Let the body cool if you feel it getting hot to the touch.
The O-ring grooves got pretty thin after this process.
Once the inside diameter of the body has been sufficiently enlarged, I flexed the metal sleeve open a bit, introducing ~5mm gap. I tried very hard to keep the cylindrical shape of the sleeve and worked slowly with my hands. I was counting on the spring-like nature of the sleeve to help me here. I expanded it to a larger diameter than the ID of the body, then gently squeezed it an fed it back into the body. It tried to expand back to its larger diameter, thus assuming the new diameter of the body. Two issues are apparent here, at the tail end, the lip in the sleeve is now too large and will catch on the tail cap threads. But also the bezel end of the sleeve had an inside groove for the top lip to rest in, which has now been sanded away.
Tail end:
Head end (you can just barely see the lip and that it's not allowing the sleeve to lay properly):
To fix the tail end, I took the sleeve back out and just used the file and 220 grit paper to reduce the lip to where it was even with the outer diameter of the threads on the body. For the front lip, I used a thin sharpie to mark how far the sleeve comes toward the head.
And then used a dremel to introduce a shallow channel for this lip to rest in. This end of the sleeve rests in a pretty thick part of the body, so no danger here of cutting too deep, but I still kept it shallow.
Once the sleeve slipped into this groove, it was ready for the 18650.
And here she is. I don't have a 3.7V bulb, so this is just the stock P60, which I was pleasantly surprised can be powered by the 4.2V freshly charged 18650.
The electrical tape on the head is for my diffuser, not part of this mod.
Hope you've enjoyed my little project.
I used common hacksaw to cut through the sleeve inside the light. Take the saw off, feed through the body of the light. I wrapped the light in painters tape so I can clamp it down lightly.
Start cutting the sleeve from the inside. I found that with my sloppy technique, the ends were cut first, so I took it slow and tried to cut evenly, only through the metal sleeve.
Once the sleeve is cut, it is easy to remove with a pair of needle nose pliers. It is just press-fit into the body, there was no adhesive of any kind. We need to save the sleeve, so be careful and take it out. Note that there are 2 different lips on the tail and head ends of the sleeve.
I obviously did a poor job here and cut into the body, but we're going to bore that part out, so no harm done.
The 18650 will be riding inside this sleeve, so I used a file to take off the rough edges in the cut and used 220 grit sandpaper to make the inside edge of the cut very smooth and dull, so as not to cut through the insulation on the 18650.
Then I used a trick I saw on youtube where someone was boring a 6p. I built up a duct tape plug on my 1/2 inch drill bit and then taped 80 grit paper to it. Using the drill I was able to quickly bore out the body to match my 18650, an EagTac 3400mAh. Because I could not use the battery for fit, since the metal sleeve will have to go back it, I built up a 1mm sleeve on the battery with painters tape to account for the 0.5mm thick metal sleeve, plus a little extra for an easy fit. I found here that sanding too quickly will get the G2 body hot and will melt gobs of plastic to the sandpaper, so take it slow. Let the body cool if you feel it getting hot to the touch.
The O-ring grooves got pretty thin after this process.
Once the inside diameter of the body has been sufficiently enlarged, I flexed the metal sleeve open a bit, introducing ~5mm gap. I tried very hard to keep the cylindrical shape of the sleeve and worked slowly with my hands. I was counting on the spring-like nature of the sleeve to help me here. I expanded it to a larger diameter than the ID of the body, then gently squeezed it an fed it back into the body. It tried to expand back to its larger diameter, thus assuming the new diameter of the body. Two issues are apparent here, at the tail end, the lip in the sleeve is now too large and will catch on the tail cap threads. But also the bezel end of the sleeve had an inside groove for the top lip to rest in, which has now been sanded away.
Tail end:
Head end (you can just barely see the lip and that it's not allowing the sleeve to lay properly):
To fix the tail end, I took the sleeve back out and just used the file and 220 grit paper to reduce the lip to where it was even with the outer diameter of the threads on the body. For the front lip, I used a thin sharpie to mark how far the sleeve comes toward the head.
And then used a dremel to introduce a shallow channel for this lip to rest in. This end of the sleeve rests in a pretty thick part of the body, so no danger here of cutting too deep, but I still kept it shallow.
Once the sleeve slipped into this groove, it was ready for the 18650.
And here she is. I don't have a 3.7V bulb, so this is just the stock P60, which I was pleasantly surprised can be powered by the 4.2V freshly charged 18650.
The electrical tape on the head is for my diffuser, not part of this mod.
Hope you've enjoyed my little project.
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