ARC Modders please help !!

Ok.. I have decided to mod my Arc LS. I was able to safely remove the retaining ring by using a dremel on it. I have the light apart. I have a couple of questions in regard to what I'd like to do to the light from here on out.

1) Replace the LED - I want to replace the stock LED with a LuxIII. I know that I need to de-solder it from the board. Once I de-solder it, how do I physically remove it from the board? I'm going to leave the boards output in it's stock configuration.

Once I have removed the old LED how do I go about attaching the new LuxIII on the board? How do I center it?

2) Reflector - I know there is a reflector for the LS available from Flashlightlens.com but I'm not sure which one it is. Does this reflector need to be modified or can I just drop it in & have it work?

3) White optic retainer ring - I assume that I no longer need this but I just want to be sure.

Please let me know if there are any parts or steps that I have missed. I'm going to order up all the items tonight.

Thanks for all your help & this modding stuff is addictive. I'm not even done with this 1st one and I'm ready to do another!

Grab the base of the LED after desoldering and pull it off, tilting the forced from side to side to get it off easier.

Scrape off the thermal goo from where the LED used to be.

Apply epoxy to the heatsink and put your Luxeon III on it, hold it down till the epoxy hardens (about 5 mins). Center is as best you can by the hole in the flex PCB - it's really just a feel you get when it's there (the PCB is slightly raised over the metal, creating a small lip), and eyeing it from the top down for it being centered.

SO17XA or XB reflectors are just drop-in over the LED.

Optic ring isn't necessary, though some suggest you use it anyway.

Good luck.

I don't like epoxy, once set it's hard to do a second time mod. I use thermal grease/paste but it's up to your choice.

If I am going to run the light at the stock mA what do you think would be the best forward voltage for the led... K or J ?

With regards to vf, the lower the better. It will run longer and cooler.

J.

Epoxy is permanent, but more effective than thermal grease. If you drop the light the wrong way you don't risk misalignment, either. Either will work, though.

Endeavour - I miss the point that epoxy adds strength to your build. Good idea.

do you ever plan on using rechargeable batteries(3.7V)?
if you do, you might want to put a high Vf luxeon in there.

I do not plan to use rechargable batteries. What benefit would a high Vf luxeon give me?

if you use lithium rechargeable (3.7V), using high Vf will help prevent your chip from burning out. If you only go stricktly using 2 AA nimh or 1 123 or up to 3V, you are better off using lowest Vf lux, since the eff will increase then.

Shiftd..

I plan to only use normal 123 cells. I'm trying to find a LuxIII emitter to use on this light but I am having a tough time finding ONE emitter & thats all I need. /ubbthreads/images/graemlins/frown.gif

The shoppe sells TV1J's or you could try to contact oeo2oo to see what he has available.

If you're only going to run on a single 123, I'd be looking for an H. I think Lambda has some QWOH 1W's for like $12 or something. You'll get a really good runtime out of that.

For centering, I've had good luck by making some partial outline marks with a fine tip Sharpie around the base of the existing Luxeon, onto the flex board. Kinda like parentheses around the base. Then visually centering the new LED inside the marks. A cotton swab in alcohol erases them afterward, as well as excess solder flux. Of course, not all existing Luxeons are well centered to begin with.

I've been thinking.. since I already have the light apart why not bump the current /ubbthreads/images/graemlins/smile.gif ! I believe that I'll need to add a resistor in the empty spot next to the existing resistor. I want to go to about 500mA, what value resistor would I use and is that the right spot to solder the new resistor (next to the existing one) ?

.22 ohm will give you ball park 560ma. I bought mine from "The Shoppe" And yes the place to solder that resistor is next to the existing R15.

Happy modding,
zwf

If you want 500 even, remove the .15, and replace with a .10. More Arc mod info in this thread.

Peter

Well.. I have all the parts in front of me and I'm going to start modding this thing tomorrow. I have already installed the UCL lens, snipped the "wings" of the reflector & have installed the reflector & the white retaining ring which centered the reflector perfectly /ubbthreads/images/graemlins/smile.gif Just one last question-

Once the light is all back together, how tight should I screw down the retainer ring? Should I just "snug" it and then give it a little bump ?

You can screw it down as tight as you want but can't screw it down too far or it will go past the threads because the reflector is a little smaller than the optics.

What about the little gold disc that is between the retaining ring & the converter board. The gold disc is loaded with Loctite residue.

Should I sand it clean with some high grit sandpaper? Do I even need to re-install the gold disc?