IMR lamps in SRTH?

[KevinL]

I'm going through a few options in my mind now. Initially I planned on a LED tower, but real soon now I am going to have a ton of XP-Gs running around. 350 lumens with 225 OTF - but really, doesn't that just become a LED version of my favorite MN16 lamp? Whiter, rounder hotspot, that's about it?

Now for the real reason why this is in the incan section. I took a look at the LumensFactory offerings and I realize we could push the frontier - let's go crazy with this one.

I currently run my SRTH on an unbored (17500 max) 3-cell D3 Defender (think C3 minus ergonomic grip, not sharpened bezel).

How about..... the IMR for M6? On 3 x IMR R123? They cleared it for the M3T on 3 IMR-123, so the SRTH is pretty similar.......

I did think about the other 700 lumen (2 x IMR-123/2 x IMR 18500) one but I'd waste a single 123 space even though I have a spacer, and/or I'd need boring.

So am I out of my mind, and will I be smelling burning Lexan soon? This IMR could give me M6-class power in a smaller light..

Alternatively, I could actually run a conventional M4 lamp with IMRs too - HMM! MN61 - at 2.3 amps that should actually be quite tame. 530 bulb lumens.

I thought about the MN21 (M6) lamp but at 5 amps I think that's way too much for my cells and I'd need to operate in a 2xIMR configuration rather than 3xIMR. If I had the light bored for 18500 I would consider that.

 

[Justin Case]

With an XP-G tower running at 1A drive and using a 90% efficient driver, power draw is perhaps 3.5W. With an MN16, you are drawing 20W of power. Big difference in run time.

The SRTH presumably was spec'ed to run with the original N62 lamp for the SF 12ZM. That was about a 28W lamp. So, I would stay within that limit to avoid any heat issues with the Lexan window.

The MN61 and IMR-M6 are both ~32W lamps. If the SRTH were still in production and there was a known, ready supply of replacement Lexan windows from SureFire, it might be worth the chance to test one of these lamps. But since the SRTH has been long out of production, I personally would not risk damaging the TH.

 

[lemlux]

Given that the run time of the N62 with 4 * cr123 was very short, I have always wondered how long the SRTH lens could run at 28W or 32W on Li-Ions without deforming. At the moment I'm running both one of my 2.5" SRTH's and one of my 3" T Heads with MN61's driven by 3@ 18650's.

I've chosen to use salvaged Sony 2350 mAh cells that test out at >2100 mAh and <2200 mAh in order to acheive a voltage drop that will be relatively friendly to the LA's as compared to my new Panasonic 2550 mAh cells that deliver between 2750 mAh and 2920 mAh.

I restrict the run times more on the SRTH setup, but I remain unsure how long I can run the larger 3" T head without damaging the lexan. (It appears that the T lens sits about 3/16" further away from the bulb than the SRTH lens.) Every time I think about getting agressive I calm down by looking at an old 6P head with lexan lens that has a 3-dimensional parabolic convex bulge caused by running either P61's or P91's for extended periods.

Has anyone unintentionally discovered the MN61 run time limits for SRTH or 3" T heads?

 

[KevinL]

With an XP-G tower running at 1A drive and using a 90% efficient driver, power draw is perhaps 3.5W. With an MN16, you are drawing 20W of power. Big difference in run time.

The SRTH presumably was spec'ed to run with the original N62 lamp for the SF 12ZM. That was about a 28W lamp. So, I would stay within that limit to avoid any heat issues with the Lexan window.

The MN61 and IMR-M6 are both ~32W lamps. If the SRTH were still in production and there was a known, ready supply of replacement Lexan windows from SureFire, it might be worth the chance to test one of these lamps. But since the SRTH has been long out of production, I personally would not risk damaging the TH.

How far we've come - it's amazing! Yes I did think about the two issues but with the SRTH I'm concerned about output I already have a LumensFactory P7 head on the way that will do LED-Turbohead duty on my M3.

Thanks for the recommendations. AFAIK, the SRTH is still available from LPS Tactical, which is a surprise, considering that we always thought it was a limited-edition or old stock product. Unless LPS has thousands of them sitting around.

I've measured the SRTH and it seems actually possible to stick a 62mm camera filter* onto the front with some epoxy, even down to the bezel ring. Hmm.. guess I might find out the hard way if I toast the Lexan. It would also detract from the SRTH being, after all, the SRTH. Unless some talented modder is able to install glass on the SRTH.

(* oops. Just remembered they are not waterproof. )

Oh, perhaps I should ask you something slightly OT. Where are you getting your turbohead LED tower drivers and XP-Gs from?

 

[KevinL]

Every time I think about getting agressive I calm down by looking at an old 6P head with lexan lens that has a 3-dimensional parabolic convex bulge caused by running either P61's or P91's for extended periods.

Reminds me of the time some years back that I left my P90 - just a MERE P90 - face down on a very hard plastic mousepad and the pad now has a 0.75" spot of melted plastic. (in fact I just lifted up my mouse to see it while typing now)

Hmm...

Well as someone who came up with the ROP I've always repeatedly reminded people to go with Pyrex/Borofloat glass and never use the stock plastic thing with the high output bulb. Perhaps time for me to take my own advice?

 

[lemlux]

KevinL:

Nailbender sells Xp-G's on NetKidz cores for $60. I have one mounted on a 6P body bored for 18650 using my other 3" T head.

As mentioned in the attached sales thread, the hot spot is about 1' at 15' with the 3 " T head and about 1.5" at 15' with the SRTH.




http://www.candlepowerforums.com/vb/showthread.php?t=274183

 

[KevinL]

Sorely tempted. You see, the other thing is I also have a turbo tower that I dug out of my parts drawer from years and years ago. I am wondering whether I am up to a challenge to try and build one :candle: - or am I simply going to botch it up good :fail: and thus should be ordering the Nailbender version in the first place anyway

There used to be a time when I'd build sandwiches out of the little 14mm converter boards and the LED carrier boards, for installation in Minimags. NOW of course, since my skills have gone downhill, I wonder....

 

[Justin Case]

How far we've come - it's amazing! Yes I did think about the two issues but with the SRTH I'm concerned about output I already have a LumensFactory P7 head on the way that will do LED-Turbohead duty on my M3.

Thanks for the recommendations. AFAIK, the SRTH is still available from LPS Tactical, which is a surprise, considering that we always thought it was a limited-edition or old stock product. Unless LPS has thousands of them sitting around.

I've measured the SRTH and it seems actually possible to stick a 62mm camera filter* onto the front with some epoxy, even down to the bezel ring. Hmm.. guess I might find out the hard way if I toast the Lexan. It would also detract from the SRTH being, after all, the SRTH. Unless some talented modder is able to install glass on the SRTH.

(* oops. Just remembered they are not waterproof. )

Oh, perhaps I should ask you something slightly OT. Where are you getting your turbohead LED tower drivers and XP-Gs from?

Yes, Lagger has them on his web site for $195 each IIRC. But does LPS really have the item, or is it a web listing that never got purged.

I've built a bunch of LED towers (Seoul P4, Cree MC-E, and Cre XP-G using the AW tower kit as well as the Netkidz tower kit. The nailbender towers are based on the Netkidz kit. The main advantages of the Netkidz kit are that the tower is set up to use inexpensive 17mm diam drivers and the kit itself is about 1/2 the price of the AW kit. The AW tower can fit only the small 14mm drivers, such as those from The Sandwich Shoppe. I still have three AW kits and four Netkidz kits in my stash.

 

[Justin Case]

Sorely tempted. You see, the other thing is I also have a turbo tower that I dug out of my parts drawer from years and years ago. I am wondering whether I am up to a challenge to try and build one :candle: - or am I simply going to botch it up good :fail: and thus should be ordering the Nailbender version in the first place anyway

There used to be a time when I'd build sandwiches out of the little 14mm converter boards and the LED carrier boards, for installation in Minimags. NOW of course, since my skills have gone downhill, I wonder....

Is it an aluminum, non-anodized AW tower? IMO, if you build an LED tower using something like a Seoul P4, then the build is relatively straightforward, especially if you use Teflon-jacketed hookup wire. It is true that the 14mm drivers from The Shoppe are not generous in the amount of space/leeway that is available for soldering. But it isn't excessively bad either IMO. It's all throughhole connections.

Another issue may be how close some components are to the edge of the 14mm driver board. There may be a possibility of component contact to the aluminum tower. Moving the inductor in-board might help. Dabbing some liquid electrical tape over the components close to the edge might help. Potting the driver might help.

If you build an XP-G tower, then you may have to make some LED die height adjustments to get the die at the right focus height. You need to know if you have a Seoul or Luxeon focus AW tower. Then, it also depends whether or not you have the XP-G on a 10mm diam, 2mm thick MCPCB or an 8mm diam, ~0.9mm thick MCPCB. Besides any die height adjustments, if you have a 10mm diam MCPCB, you'll have to trim that down to ~8mm diam to fit through the TH reflector opening.

 

[KevinL]

Great, thanks for the information. I'd love to continue discussing it, but I think they are nearly about to throw us out of the incan forum, so I have created a thread in Homemade for us to continue the conversation.

http://www.candlepowerforums.com/vb/showthread.php?t=294559