I admit I am a lurker on here and my job doesn't exactly let me surf the forum as often either.
However, when I do have time there is just something I enjoy about voiding a warranty on an expensive item and turning it into something unique and (for me) more useful.
I am a Naval Officer by trade and I was looking for a light that had at least both white light for regular lighting and a dim and bright red for bridge work at night. However I didn't have much use for the blue light in the Kroma and as an officer I do have to do habitability rounds on the ship and you can see where UV might come in handy there. As well, I am also a hunter so I could foresee some benefits to using it in the bush.
Why not just mod a regular LED light into a UV one? well... why not! The Kroma is a great multi-spectrum light, is well built, and well... I could afford it.
I basically copied the technique from an old thread on here and enlisted the help off of other guys on the web. It was a huge learning process but very very handy.
Well, months ago I started theproject with my Surefire Kroma flashlight.
I used Nichia 365nm UV LEDs based on recommendations on here. They are bright enough to be useful but have a low enough spectrum to actually be useful lol. You have to fax in a disclaimer before ordering them as they are some pretty powerful little lights:
They are definitely larger than the original UVs found in the light but still are able to fit in the final MOD
Following that thread I first tried to get the flashlight apart. It was definitely NOT easy. The threads were locktighted heavily and after investing in a proper torch and some belt wrenches I got it apart.. Wow was that a lot of work:
First task was to get the selector switch off for two reasons. First, with the ring on there isn't enough surface area to get enough room to put a wrench on both the top sections and the main part of the head. Second, you can't torque the selector ring, there is a little plastic part inside that gives it the proper clicky feel that will break if you twist it too hard.
So After doing some reading there is a way to do it with aluminum shims and an exacto blade: Details on how can be found here: http://www.candlepowerforums.com/vb...-take-that-liquid-weld!&p=2427471#post2427471
It took a while but I got it off with minimal marking in the ring:
You can see that now the ring is off I have lots of room to use a wrench for torque:
Now the head has two parts screwed on top. The first and much easier to remove section houses the glass. That came off pretty easy:
The second is a ring that holds in the light assembly and LEDs, that was on there really really good and after fiddling with numerous wrenching methods and heat levels it took a TON of heat and a lot of torque with a vise grip and a rubber bike tube on the bottom and a strap wrench on the top to get it to finally give.
This was a battle!
Then using a small flathead screwdriver it was easy to work out the chip and lens assembly: Quite the complicated system!
So there you have it folks, a breakapart picture of a Surefire Kroma!
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**Fast forward many months**
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It's done! Very sorry I didn't take any pictures of the de/soldering part
Soldering is tough as you have to heat and remove the solder at the base of the LEDs without messing with the other components nearby. There are two main ways to do it. one is to cut the LED stems so You only have to do one at a time (but lose the LED) or heat each back and forth and work it out that way. I used a goot soldering iron as they have a better selection of very pointy tips.
Also make sure the LEDs are placed in the right direction otherwise they won't work at all. For these, the the Nichia LEDs have a little tab and when they were faced inward they were set properly.
The other trick was to make sure the LEDs were soldered at the right height so the glass lens could go back in properly underneath the LED edges.
One thing I would have done is use a pair of small flushcut pliers to snip off the edge of the UV LEDs and trim them to be a bit more flush over the glass, but thats a tiny part.
And for anyone else planning to do it, you need LOTS of heat to get the top part screwed off, if not you risk marking up the head with too much force with pliers, etc
Putting it back together I basically scraped off the old loctite remains so the threads would go back on nicely and put on a bit of blue loctite this time.. not going through the red stuff again ugh.
Putting the selector switch back on properly was much easier than taking it apart. I just put the metal ring back in place and used some shims to slide the ring over top of the metal ring and then once in place removed the shims and it is back to working just like before. One thing I would have done differently was do a better job of tightening the head back on before putting the selector ring back on as once you do that you are back to the same issue of lack of spots to put torque on without risking the integrity of the selector ring.
That and thank god it is over. I ended up being way more daunting than I anticipated. Especially for a first mod.
However, when I do have time there is just something I enjoy about voiding a warranty on an expensive item and turning it into something unique and (for me) more useful.
I am a Naval Officer by trade and I was looking for a light that had at least both white light for regular lighting and a dim and bright red for bridge work at night. However I didn't have much use for the blue light in the Kroma and as an officer I do have to do habitability rounds on the ship and you can see where UV might come in handy there. As well, I am also a hunter so I could foresee some benefits to using it in the bush.
Why not just mod a regular LED light into a UV one? well... why not! The Kroma is a great multi-spectrum light, is well built, and well... I could afford it.
I basically copied the technique from an old thread on here and enlisted the help off of other guys on the web. It was a huge learning process but very very handy.
Well, months ago I started theproject with my Surefire Kroma flashlight.
I used Nichia 365nm UV LEDs based on recommendations on here. They are bright enough to be useful but have a low enough spectrum to actually be useful lol. You have to fax in a disclaimer before ordering them as they are some pretty powerful little lights:
They are definitely larger than the original UVs found in the light but still are able to fit in the final MOD
Following that thread I first tried to get the flashlight apart. It was definitely NOT easy. The threads were locktighted heavily and after investing in a proper torch and some belt wrenches I got it apart.. Wow was that a lot of work:
First task was to get the selector switch off for two reasons. First, with the ring on there isn't enough surface area to get enough room to put a wrench on both the top sections and the main part of the head. Second, you can't torque the selector ring, there is a little plastic part inside that gives it the proper clicky feel that will break if you twist it too hard.
So After doing some reading there is a way to do it with aluminum shims and an exacto blade: Details on how can be found here: http://www.candlepowerforums.com/vb...-take-that-liquid-weld!&p=2427471#post2427471
It took a while but I got it off with minimal marking in the ring:
You can see that now the ring is off I have lots of room to use a wrench for torque:
Now the head has two parts screwed on top. The first and much easier to remove section houses the glass. That came off pretty easy:
The second is a ring that holds in the light assembly and LEDs, that was on there really really good and after fiddling with numerous wrenching methods and heat levels it took a TON of heat and a lot of torque with a vise grip and a rubber bike tube on the bottom and a strap wrench on the top to get it to finally give.
This was a battle!
Then using a small flathead screwdriver it was easy to work out the chip and lens assembly: Quite the complicated system!
So there you have it folks, a breakapart picture of a Surefire Kroma!
\/
\/
\/
**Fast forward many months**
\/
\/
\/
It's done! Very sorry I didn't take any pictures of the de/soldering part
Soldering is tough as you have to heat and remove the solder at the base of the LEDs without messing with the other components nearby. There are two main ways to do it. one is to cut the LED stems so You only have to do one at a time (but lose the LED) or heat each back and forth and work it out that way. I used a goot soldering iron as they have a better selection of very pointy tips.
Also make sure the LEDs are placed in the right direction otherwise they won't work at all. For these, the the Nichia LEDs have a little tab and when they were faced inward they were set properly.
The other trick was to make sure the LEDs were soldered at the right height so the glass lens could go back in properly underneath the LED edges.
One thing I would have done is use a pair of small flushcut pliers to snip off the edge of the UV LEDs and trim them to be a bit more flush over the glass, but thats a tiny part.
And for anyone else planning to do it, you need LOTS of heat to get the top part screwed off, if not you risk marking up the head with too much force with pliers, etc
Putting it back together I basically scraped off the old loctite remains so the threads would go back on nicely and put on a bit of blue loctite this time.. not going through the red stuff again ugh.
Putting the selector switch back on properly was much easier than taking it apart. I just put the metal ring back in place and used some shims to slide the ring over top of the metal ring and then once in place removed the shims and it is back to working just like before. One thing I would have done differently was do a better job of tightening the head back on before putting the selector ring back on as once you do that you are back to the same issue of lack of spots to put torque on without risking the integrity of the selector ring.
That and thank god it is over. I ended up being way more daunting than I anticipated. Especially for a first mod.
