Dummy reference guide to SF A2 modding with MJ led (or 35k 5mm) leds

AuroraLite

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Dummy reference guide to SF A2 modding with high output 5mm leds

Hi, all!

Got home today early for a change, after reading KevinL post about 35k led vs other leds in led section and some struggle deep within (for like, 5 minutes)--I had decided to mod the SF A2 Aviator into a hybird with 35k mcd leds.

The result is definitely satisfying and the process is fun(but part of it is a pain in the behind). :laughing: :devil:

Swapping the leds in a SF A2 probably has been done and mentioned in the past, and the following is just some pictures and description of how a dummy do it :p

Update 23/9/05--I have finally decided to switch in the MJ uncut leds into the SF A2 led swap mod. The main reason behind this is the level of overdrive a led could take--if my calculation is correct, then the 35k or original leds are driven pretty hard at 78ma.

It might work well with the original leds, but there is an uncertainty about how much the 35k could take or how long will it last at that level.

For me, since this light will become part of my EDC inventory, though the 35k is truly amazing in terms of its very tight concentrated beam, I cannot bear this uncertainty/risk that these leds' output might diminish over time(or in a short frame of time).

Thus, I have decided to swap in the MJ uncut leds for the SF A2, which is more floodish but just about as bright. More pictures at the end. :)




First, unscrew the led ring from the bezel. Slowly wiggle the led ring out.




The led ring without the anode ring. This is the only painful part of the whole process, to undo the anode contact ring from the led ring. I have so much respect for the SF quality of work, even for a small piece, it is well designed and so securely attached together.




This is the anode ring that has been taken off the led ring. You probably have to take it out to mod the leds properly. The trick is to use a solder wick to absorb all the solder off where it is connecting the anode ring and led ring. Then put the solder iron on top of the little tab and wiggle it loose from where it is...finally use a real sharp knife to slowly pill the anode ring off the led ring while heating it up with a solder iron. Be very careful since both the layout of led ring and the anode ring are both quite delicate. If you destroyed either one or damaged it too badly, there is no turning back!! :devil:

Another easier route could be done if you just snap the legs of the original leds and solder the new one on top...but you'd better be lightning quick, since there is hardly any solder connecting the leds to the led ring.




Swapping the leds in process. I have measured the three little SMD resistors mounted before the leds, and each is 33.3 ohm. And when I engage the first stage of the switch, the voltage supply is around 6v. So if the Vf of this 35k is around 3.4v(Got these leds from a fellow flashaholic friend, Aw), then the V drop by resistor will be around 2.6v; and the I for each led will be around 2.6v/33.3ohm=78ma each. Definitely overdriven if the spec is at 20ma nominal for most leds, but further research will need to be done for a long term effects. So far so good. :)

Also, depending the leds that you plan to put in, you might have to dremel the protroding latch at the botton of the led flat, so it could fit into the led holes on the A2 bezel.




Viola, it works! Do check the new leds that you plan to swap in before you solder them on, and double check again with supply 3 x 1.5v to the led ring.




Another view from the back of the led ring


Comparisons, all pictures used the same exposure and shutter speed settings:


Original SF A2 vs Attitude



Original SF A2 vs 26k modded Attitude



SF 35k leds A2 mod vs Attitude, it just completely blows it out of water...and the 35k seems to be quite narrow in terms of its beam characteristics.



SF 35k leds A2 mod vs ARC AAA rev4(with Nichia CS, Issac, thanks for the correction :) )

Yet another swap
As stated in the update at the beginning of this post, finally, I have decided to put in the MJ uncut leds. They are more capable of handling long term overdrive so as long it is under 100ma. Assuming its nominal Vf is around 3v(which IIRC, it does not have as high Vf as normal 5mms), then the drive level is about ~90ma. Here are some comparison pictures of the SF A2 with MJ leds:


Original PT attitude, a comparable output to the original A2


SF A2 with MJ led, this picture does not do a complete justice of the level of light it gives...but comparing it to 35k, it is quite flood-ish and the light generated is about the same(or just a little less, from my naked eyes). Still, a really good improvement over common 5mm leds(which PT attitude is comparable to the original SF A2)


SF A2 35k leds mod, notice the beam is tight and the darker area unlit by this tight beam.


SF A2 MJ uncut leds mod, note the flood beam also covers the unlit area not lit by the 35k. And I am a lot of comfortable with this mod, knowing this tool will perform well and I can count on it when needed to. :grin2:


Thank you for reading, hope yod have enjoyed the pix! :)
 
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leukos

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

AuroraLite,
Great post! I have zero soldering skills, so let me know if you would ever do this mod for other CPFers and what you would charge. I would love to have some newer LEDs put in a couple of my A2s! :)
 

greenLED

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

I luv your Dummy guides! Thanks for doing this for those of use with limited modding skills.
 

Krit

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

I see 100 mA LED in Dat2Zip and thinking to replace to A2'led. A2 can use with 2*r123a and still over drive stock led, so I will replace with 100 mA led to obtain more current. Now I get 100 mA led in my hand but I have no time to change it. :(
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Leukos,
Thanks for the kind inquiry, flashaholism is mainly a hobby, and I have no idea how much should a mod like this would go for. I have heard it cost a rediculous amount for a new ring of leds(something almost the price for a new A2?), but it doesn't really require excellent solder skill and it will be silly to pay so much for a mod like that. Probably patienence and time are what one needs more for this. Anyway, if time ever permits(which is not very likely for the next few months)...keep in touch. :wave:


Wquiles,
No, thank you for reading! :)


greenLED,
As always, I am truly thankful for your kind support. I don't think there is ever a modder who has no skill, but just modder who hasn't discovered his/her skill. Besides, my easy mods are hardly comparison to those who had set foot and make history on CPF. My kudos to all those contributing mod masters! :rock:


Krit,
I redo my calculation and if my assumptions are correct about the Vf of those 35k(around 3.4v), then they are overdriven at around 78ma each. The uncut 5mm Mj leds are probably great candidates for this mod then, since it will probably still be overdriven but not to the max. Please do show us your result when you are done! :naughty:
 
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AW

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Auroralite,

Very nice mod indeed. I guess you'll have to swap them again for the 40K mcd 5mm LED very soon since they are now available from the same manufacturer.

40000mcdspec.jpg
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Haha, Aw!

Thanks for spec. At any rate, I will just keep my solder iron hot and ready! :devil: :laughing:
 

IsaacHayes

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Correction to first post: ArcAAA rev4 uses a Nichia CS LED. :) Not sure if it's a U-bin they use, but I have some U-bins that I'll be putting into my arcaaa. Now THAT's going to be hard!!

BTW not sure why the andode ring was removed, but then again I don't have an A2. :) I've done 5/8 led Xnova led replacements, and once you get used to it, it's just time consuming (desoldering 16 leads, then heating up the holes 16x to slide the led in, then anothe 16 times to add more solder to finish them up!) (I can't find my desoldering braid)
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

IsaacHayes said:
Correction to first post: ArcAAA rev4 uses a Nichia CS LED. :) Not sure if it's a U-bin they use, but I have some U-bins that I'll be putting into my arcaaa. Now THAT's going to be hard!!

BTW not sure why the andode ring was removed, but then again I don't have an A2. :) I've done 5/8 led Xnova led replacements, and once you get used to it, it's just time consuming (desoldering 16 leads, then heating up the holes 16x to slide the led in, then anothe 16 times to add more solder to finish them up!) (I can't find my desoldering braid)

IssacHayes,

Thank you for the correction, post corrected! :)

The reason for removing the anode ring is because there are three tongues that sprung out from the ring as contacts to the body. And those three tongues are covering where the solder points for the three leds at the base of the led ring.

Certainly, one could use brute force to bend those tongues backwards and try to access the leds...but I worry the fact that it will be bent out of shape permanently and even then, it would be harder to solder those leds straightly lined up and all approximately equal in height when the tongues are in the way.

What I did after removing this anode ring is, to de-solder the leds, then replace those with three new leds that all has very identical lenght of trimmed legs.

Afterwards, solder the new leds onto the led rings, and finally, place the led ring flat on a glass, heat up the solder point to get each of them to adjust for striaghtness and the height. As you have said, it is not a really that difficult of work, but do needs patience and time... :sweat: :laughing:
 

IsaacHayes

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Ah I see. A2 seems like a really cool light. I'd like to see a light with luxeon & reflector, and with 5mm led all around the bezel up close by the lens. You could have a rotating collar like the U2 that would select between white led, red, green, UV, etc :D Crazy Idea but it'd be like every A2 rolled into one.

I'm almost done with my ArcAAA Nichia CS swap. I had to re-solder the wires of the inductor back to the inductors SMD base(the part that is soldered to the board)!!! Actually I think the wires were originally spot welded/melted. You can see the details of it here. :)
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Isaac,

Maybe all the flashaholics think alike? I did make some prototype of what you have mentioned(not as crazy as four colors with bezel twisiting operation, which btw, a really cool idea) with 2 leds and a luxeon in the middle. Turns out the bezel is too small for such mod, but now that you have mentioned it...I think I ought to give it another try! :naughty:

A2 indeed is a really cool light...but somehow, my local flashaholic friend and I are having conspiracy theory that maybe SF will come out with a new light, similar to A2, but with lux in the middle and different colored leds as back up/option in the reflectors...for example, Lux III or V in the middle with IR leds or red leds...SF, are you listening?

Btw, I am thinking yet another swap for the A2 35k...maybe with the Mj led uncut this time--Krit got a really good and valid point, after some reading and researching, it seems the Mj leds are more durable in a long, long run for overdriving. What do you all think? :poke:


I had seen the similar ARC AAA led swap in the past, and I am sure the result should be quite satisfying. Very informative thread, a future project I shall pick up in the future.
 
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makar

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Great thread :thumbsup:
How will this modification affect the runtime compared to the standards sf version?
 

js

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Great thread, AuroraLite!

Thanks for posting this.
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Makar and Js,

Thanks for reading! AFAIK, this 35k leds have a nominal Vf of 3.4v and if the original leds do have the same or similar Vf and the spec I forward as 20ma, then the runtime should remain the same or somewhat similar. From FLR site, it has stated that the leds are not regulated, so it will just drop very gradually from beginning to 50% in 15 hours.

Actually, what I'd like to know is whether there is a way to guesstimate as how many hours of leds usage is equal to incan usage for the A2?
 

IsaacHayes

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Auroralite - Perhaps take one of those cheap china lights on ebay/etc that have like 32 or whatever LEDs in them. Get one that has a side clicky switch. Swap the switch for a 2 stage switch like people do for the QIII. (only this one will be on the side barrellel, so you can wire up it to switch between 5mm and luxeon, instead of a resistor). Then hack out the LED board and leave only the outermost ring of LEDs. Then find a reflector (IMS?) 17mm/20mm/27mm etc that fits in the center. Get some aluminum and mount an emitter and grind it to fit in the head. Drill holes for wires, Wire up the 5mm ring, and the luxeon. drop in the reflector, Artic Aluminua/silver Epoxy the aluminum HS into the head, solder the wires to the 2 stage switch. And there you have a dual 5mm/luxeon home made light! I'll leave the color of LEDs (and rotating collar LED selector) up to you to figure out! :D Actually 360nm fox UV would be cool in a A2....

As for swapping out the 35k for MJLED, well those are speced at 100ma or so, so I'd think they'd tolerate the higher "overdrive" levels of the A2 better, and perhaps make more light (they have a wider beam angle) too. That or put some Nichia CS U-rank LEDs in. Those would be just as bright/brighter than the 35k and at over drive levels they don't dim down/fade like the 35k does over time.
 

Krit

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

I carry A2 along the beach at night and the led light is not enough for my safety walking. I found sea snake at beside the beach, and difficult to see what it is. I step over the snake and I just know that it is not the string.

I come back and think A2 is the multipurpose light for me and led mode is just suit for camp life or close up work. It's not suit for safe walk in total dark area which we do not clear enough.

I see the uncut 100 mA MJled and think the way to mod to the brighter led mode for A2. This should be the A2 which best for me and I can use other mini led in latent area instead.
 

Krit

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

AuroraLite, I do not change my A2's led yet. I have every thing in my hand now but I'm in my hard luck from termite in my house. :-(
 

AuroraLite

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

Krit,

I managed to put 3 Mj uncut led with 40 ohms each, powered by 4x1.5v batteries to simulate the 3 leds ring in A2. The result is a splash of creamy white light. I think I am at an intersection to decide whether to keep those 35k in the A2, knowing that it is quite overdriven and destined to diminish overtime, or simply to put in the 3 Mj leds. The pros about the 35k over the Mjs is that it does give a very concentrated beam shot(like behind an optics) vs Mj's 'wall of light'...current 5mm leds inherently will be no where near as bright as the current lux, and the focused beam pattern does have its appeal over a flood light for me.

How would you all choose if you are in my shoes?

Btw, take your time, Krit, no worries or anxiety attack! :)
 

Krit

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Re: Dummy reference guide to SF A2 modding with 35k 5mm leds

AuroraLite, in my opinion, propose of use is major decision supporting. I think the stock led is not throw enough for walking so I will change to uncut MJ for good throw as I rough test.

For your objective, 35K led makes a smooth plenty light in close up use. So, if the led cost is not too high. You can change them after diminish.

Thanks for your auxiliary.
 
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