# Big Red: SST-90 8.4A regulated 8AA Mag 2D rebel reflector



## Techjunkie (Mar 12, 2010)

(White-wall beamshot comparisons in post #8)

A while back, I experimented a bit with different direct drive solutions for an SST-90 emitter. In the process, I had created a Mag 2D with a very low resistance, high current capable 4s2p AA configuration. Eight AA Duraloops providing 4.8V in that torch proved to be too much power to direct drive the SST-90 with, driving it to more than 14 Amps.

Since then, I've been collecting the pieces to build something new from that host. First, I needed an inexpensive regulator that could fully drive an SST-90 from 4.8v input and fit in a small space. Enter three single-mode 2.8A 8xAMC7135 regulators (cheap ones from KD).

I also wanted to use the 40mm deep SMO Mag Rebel reflector, which is just awesome. It wont focus anything north of the top of the Mag tube, so recessing the SST-90 into the neck was necessary. I asked another, VERY KIND CPF'er if he'd turn a bit of Aluminum stock into a plain flat heatsink for me, and several days later, one arrived in the mail! :twothumbslovecpf What a good fit too! I really had to apply force to fit it in the neck after greasing it with Arctic Silver. He even cut a relief into the bottom for me to fit a driver, and it was a good thing too, 'cause I ended up needing that space.

Here's a pic of the heasink after I drilled and tapped six holes by hand, and the three regulators after I prepped them with 20awg stranded copper:






I used thicker 18awg stranded copper to connect the combined regulator leads to the switch and to the emitter's star.

I mounted the bare emitter onto a standard 20mm CREE XR-E star using solder paste and a frying pan. (Delicate work that I'm not too fond of.)

In the end, I had not recessed the heatsink enough to entirely fit the whole depth of the Mag Rebel reflector and still screw the bezel/head passed their gaskets. I solved that problem by cutting off the top lip of the reflector and then slid the reflector through that ring-shaped piece to give it something to hang from. In effect, I moved the lip 1-2mm down the reflector. (I also trimmed 1.5mm more than necessary from the bottom, but that doesn't appear to have affected focus.) You might see a very slim black ring around the reflector in the pics. That's the exposed edge of the cut reflector. I used a black sharpie to hide the raw blue plastic.






(Current draw shown in pic above is just the sudden in-rush at first touch of the DMM leads. It instantly settles down to ~8.4A. I just couldn't juggle the leads and the camera to snap off another in-focus shot.)

I might redo the reflector and cut 1.5mm less of the cam off, although the fact that it doesn't directly contact the brass screws that hold down the star might be the only thing keeping its bottom from melting.

I might also do some green glow around the emitter, although the screws and wires would still be visible 'cause they're taller than the emitter base.

I might just not mess with it again and call it done...yeah, right, like I have that will power.


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## Al Combs (Mar 12, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

Very nice build. I like the use of the 7135's while we wait patiently for the more exotic stuff comes along. I saw your YouTube video of the aspheric SST-90 and the clamp meter. Have you been able to make any direct comparison between the Rebel reflector and the more common incandescent reflector? How long can you run it at full power before shutting down? Beamshots?


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## Mettee (Mar 12, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

I feel your pains, I recently did close to the same thing but with a P7/d2flex/rebel reflector combo. IF only the AMC's were smaller you could have sunk that heat sink down a bit. The heat sink with the P7 is almost all the way down and the d2flex is recessed into the heat sink... so there is room. You are encouraging me to do a write up.


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## Dioni (Mar 12, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

Nice!

:goodjob:


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## Techjunkie (Mar 12, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*



Al Combs said:


> Very nice build. I like the use of the 7135's while we wait patiently for the more exotic stuff comes along. I saw your YouTube video of the aspheric SST-90 and the clamp meter. Have you been able to make any direct comparison between the Rebel reflector and the more common incandescent reflector? How long can you run it at full power before shutting down? Beamshots?


 
Rebel reflector gives a much tighter/smaller, rounder spot than the traditional reflector or any of its copies. I _really_ like it. A distant second was a 53mm wide by 30mm deep CREE XRE reflector that I got from DX and then modified to fit. That's my back-up in case this one melts. 
Batteries are NiMH, so I guess runtime is limited to how much I'd be willing to abuse them. The "pack" is 4000mAH and draw starts at 8.4A and then lessens as Vbatt drops, so ballpark guess is ~40 minutes total.
Beamshots are inevitable.



Mettee said:


> I feel your pains, I recently did close to the same thing but with a P7/d2flex/rebel reflector combo. IF only the AMC's were smaller you could have sunk that heat sink down a bit. The heat sink with the P7 is almost all the way down and the d2flex is recessed into the heat sink... so there is room. You are encouraging me to do a write up.


 
I really like the Mag Rebel reflector. I'm working on an old 2C SSR-50 build with it and a recessed Cu heatsink that I made with some plumbing supplies. The C head is taller than the D head, and my heatsink is shorter than this one. Also, I'll be using 2 DX 20330 drivers in that torch, which I think might be shorter together or about the same as the drivers I used here on their ends. If all goes well, I wont have to chop the top off of that reflector. If I have to, at least I know it can be done. Losing that top 2mm probably results in a slightly larger hotspot, but it still beats the heck out of any other reflector I've tried (and I've tried all the affordable ones).



Dioni said:


> Nice!
> 
> :goodjob:


 
Thanks


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## Al Combs (Mar 13, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*



Techjunkie said:


> Batteries are NiMH, so I guess runtime is limited to how much I'd be willing to abuse them. The "pack" is 4000mAH and draw starts at 8.4A and then lessens as Vbatt drops, so ballpark guess is ~40 minutes total.


Sorry, my mistake. By runtime, I was wondered about the heat build up, not battery life. Interpolating from the Luminus doc's, I get about 3.52 volts @ 8.4 amps. Of course that's only the 'average' LED. But it has to be close to 30 watts. My 10 watt P7 Mag gets hot pretty quick, but will run continuously. Almost 30 watts of power from an SST-90 must get you to the edge pretty quick. I want one.:naughty:


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## Mettee (Mar 14, 2010)

*Re: SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

wrong topic


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## Techjunkie (Mar 22, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

Here are some white wall beamshots from my Luminus + Mag Rebel reflector creations compared to more traditional P7 and MC-E in 53mm MOP reflectors.



















<<<The torch this thread is about


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## Dioni (Mar 22, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

Wow...  nice!

It has a considerable bigger and brighter hotspot. The first impression is that it also has a more bluish light compared to the others. Is the light so more bluish?

Thanks for the beamshots!


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## irv_usc (Mar 23, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

so.. where did you get the heatsink?


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## Techjunkie (Mar 23, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*



Dioni said:


> Wow...  nice!
> 
> It has a considerable bigger and brighter hotspot. The first impression is that it also has a more bluish light compared to the others. Is the light so more bluish?
> 
> Thanks for the beamshots!


 
It's a 6500K tint, which is why it appears cooler than all the others, but it's bin is right on the BB locus, so as cool as it is, it's a pretty pure white without hue of green or pink.



irv_usc said:


> so.. where did you get the heatsink?


 
I PM'd another member who had mentioned turning some stock to make the same kind of heatsink in his own build thread. He was kind enough to make me one too. (He's not one of the folks who makes the more exotic kind of heatsinks sold here so often for epoxying bare emitters to.) I don't think it would be appropriate for me to volunteer who he is in case he wants to start charging for that kind of thing, or doesn't want to be inundated with requests for freebies. (But he should feel free to reply here if he does.)

As an alternative to a custom fit heatsink, you could custom fit the Mag neck to fit a piece of bare extruded Al stock instead. Speedymetals.com sells 35mm (1 3/8") T6061 for pennies, and they'll even cut it into discs of varying thickness for you (with a margin of error of ~0.25"). I was about to do that the same way that I increased the ID of the battery compartment (with a 35mm hole saw and/or a brake hone), but the anonymous CPFer came to the rescue the same day that the bare stock arrived at my door.


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## vestureofblood (Mar 27, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

Its good to know that these LED will fit on to a cree star. I have put a few leds on to boards in a similar manner to what you did, but just using solder and flux. What exactly is solder paste? I have heard of it, but never used it.


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## Techjunkie (Mar 27, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*



vestureofblood said:


> Its good to know that these LED will fit on to a cree star. I have put a few leds on to boards in a similar manner to what you did, but just using solder and flux. What exactly is solder paste? I have heard of it, but never used it.


 
It's microscopic beads of solder held together with what I assume is some kind of flux. I use the Lodestar one, sku 4711 from DX, and thin it out a little with rosin flux from RadioShack (64-021). You can use it in a syringe or just spread it on with a pick. I heard that it can go bad after opening if you don't refrigerate it, so I keep mine hidden in the bottom of the refrigerator labeled "poison" (this one has lead in it). I've had it for a very long time and it still works as well as the day I got it. 50g is a massive amount too. One container is probably a lifetime supply (if it never expires).


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## vestureofblood (Mar 27, 2010)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*

I think I may have to order some of this, I have been just very lightly tinning the emitter and star, then heating the base of the star, and putting an ice cube under it after the solder wets. It works ok, but its hard to get the solder thin enough to allow the led to sit perfectly flat.


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## moviles (Apr 30, 2010)

Techjunkie said:


>



good mod and nice heatsink :thumbsup:

sst-90 with cree star? its that really possible? 


















I prefer buy the SSR-90 (with star) but that appears to be good option too



:twothumbs

no damaged noticed on the led?


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## Techjunkie (May 1, 2010)

moviles said:


> good mod and nice heatsink :thumbsup:
> 
> sst-90 with cree star? its that really possible?
> 
> ...


 
Thanks.

No damage, and this thing rocks. Heatsinking is perfect for the 8.4A current. I LOVE this torch.

I tried to find blank SSR-90 stars for the bare SST-90 emitter that I already had on hand, but could not, so I went with an XR-E star, and it worked. Seeing is believing.


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## DeeperDeeper (May 11, 2010)

Which 7135 circuit did You use ? ProductId=1770 ?


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## Techjunkie (May 11, 2010)

DeeperDeeper said:


> Which 7135 circuit did You use ? ProductId=1770 ?


Yes, exactly.


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## busylifemeto (May 28, 2011)

*Re: (Beamshots post 8) SST-90 8.4A regulated 8AA Mag 2D rebel reflector*



vestureofblood said:


> Its good to know that these LED will fit on to a cree star. I have put a few leds on to boards in a similar manner to what you did, but just using solder and flux. What exactly is solder paste? I have heard of it, but never used it.


 
Hi guys, sorry to tell you the SST does NOT fit properly on a CREE Heatsink. When you get to high drive current it will collapse. The reason I know is I tried it . I make lights professionally and trust me you need the Luminus SSR Heatsink. Even if you have this heatsink it is only for the experienced to place it. It needs the right amount of paste and needed to be reflowed. Why not but the LED on the Star Board ? :shakehead


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## busylifemeto (May 28, 2011)

Techjunkie said:


> Thanks.
> 
> No damage, and this thing rocks. Heatsinking is perfect for the 8.4A current. I LOVE this torch.
> 
> I tried to find blank SSR-90 stars for the bare SST-90 emitter that I already had on hand, but could not, so I went with an XR-E star, and it worked. Seeing is believing.


 
Hi, the Luminus LEDS do not fit well on CREE star boards. Its OK if you keep the drive low but if running them at spec they get as hot as hell. I use them professionally and I only has the LEDS in the beginning and wanted to get them going. From three, two failed within weeks. Just trying to help dude.


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## Techjunkie (May 29, 2011)

busylifemeto said:


> Hi guys, sorry to tell you the SST does NOT fit properly on a CREE Heatsink. When you get to high drive current it will collapse. The reason I know is I tried it . I make lights professionally and trust me you need the Luminus SSR Heatsink. Even if you have this heatsink it is only for the experienced to place it. It needs the right amount of paste and needed to be reflowed. Why not but the LED on the Star Board ? :shakehead


 


busylifemeto said:


> Hi, the Luminus LEDS do not fit well on CREE star boards. Its OK if you keep the drive low but if running them at spec they get as hot as hell. I use them professionally and I only has the LEDS in the beginning and wanted to get them going. From three, two failed within weeks. Just trying to help dude.



Nice try, troll. Not taking your bait.


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## jh333233 (Aug 18, 2011)

That was a impressive light
The hotspot is very bright, in the pics whole room became bright too,
what was the spill angle?


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## Techjunkie (Aug 18, 2011)

jh333233 said:


> That was a impressive light
> The hotspot is very bright, in the pics whole room became bright too,
> what was the spill angle?


 
I don't really know. The rebel reflector does cast a brighter, narrower spill than the original Mag reflector, so whatever it is, it's tighter than that. I've never taken the time to calculate it though.


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## Mattaus (Aug 18, 2011)

Is it possible to slave the drivers off each other and use one of the Shiningbeam drivers as a 'control' board? So you get the high current output, but the selectable modes as well? They're all 7135 based boards so I 'assume' it would be possibe, but having never tried it before I can't be totally sure.


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## moderator007 (Aug 18, 2011)

Mattaus said:


> Is it possible to slave the drivers off each other and use one of the Shiningbeam drivers as a 'control' board? So you get the high current output, but the selectable modes as well? They're all 7135 based boards so I 'assume' it would be possibe, but having never tried it before I can't be totally sure.


This has been known to work with slaved 7135 boards. One board with modes the rest with out. Or you can remove the ic from the other two you wish to slave.


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## Techjunkie (Aug 18, 2011)

Mattaus said:


> Is it possible to slave the drivers off each other and use one of the Shiningbeam drivers as a 'control' board? So you get the high current output, but the selectable modes as well? They're all 7135 based boards so I 'assume' it would be possibe, but having never tried it before I can't be totally sure.



I can be totally sure, as I've done it, recently. <--- In that build, one 2.8A board with modes controlled the other two 2.8A plain-Jane boards as you've suggested. The only difference there is that instead of the three boards combining the current into a single SST-90, each controlled the individual current of one of the three XM-L emitters. Otherwise, the wiring is exactly the same. As in...


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## moderator007 (Aug 19, 2011)

techjunkie, when you connected the second star for the three modes. Did you simply solder it to ground or did you remove the default trace at star four. And solder ground to star 2. I read that it wasn't necessary to cut the trace to pin 4 default.
Or did you just use shining beam's 3 mode model. I have always removed the trace. Just trying to confirm if im doing unnecessary work.


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## Mattaus (Aug 19, 2011)

Techjunkie....thanks for the reply. So if I was to power a single SST-90 with modes it'd be exactly the same setup as per your 3 XM-L mod, but obviously (I hope or I'll look a little silly) the +ve and -ve leads will all go to the same +ve and -ve solder pads on the single SST-90 (parallel accumulates current to be very basic about it). Correct? Seems damn easy to do!


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## Mattaus (Aug 19, 2011)

I'll do some looking around for pictures a little later, but what's the throw on these triple emitter mods like? Obviously the LEDs are sitting a lot closer to the lip of the light than single emitter setups so the reflectors will ahve little effect on the throw. I'm assuming anyway. Probably excellent floodies, but useless in the wide open really...unless their throw is better than I suspect.


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## Techjunkie (Aug 19, 2011)

moderator007 said:


> techjunkie, when you connected the second star for the three modes. Did you simply solder it to ground or did you remove the default trace at star four. And solder ground to star 2. I read that it wasn't necessary to cut the trace to pin 4 default.
> Or did you just use shining beam's 3 mode model. I have always removed the trace. Just trying to confirm if im doing unnecessary work.


It's not necessary to cut the ground on the fourth star when using any of the other three. I've tried it both ways and haven't noticed a difference. Possibly, when using hi-lo-strobe (3rd star) the strobe might have been faster with the fourth star cut, but that could just be a different program on the prom from one board to another. On a side note, I used the 4-star 2.8A regulators to control the mode selection on my triple SST-50 and on my triple XML, and the order is reversed between the two. The XML goes High-Mid-Low whereas the SST goes Low-Mid-High. I think I got the latter one from DX, whereas I've always gotten all my others from KD.



Mattaus said:


> Techjunkie....thanks for the reply. So if I was to power a single SST-90 with modes it'd be exactly the same setup as per your 3 XM-L mod, but obviously (I hope or I'll look a little silly) the +ve and -ve leads will all go to the same +ve and -ve solder pads on the single SST-90 (parallel accumulates current to be very basic about it). Correct? Seems damn easy to do!


 Yep, you've got it.



Mattaus said:


> I'll do some looking around for pictures a little later, but what's the throw on these triple emitter mods like? Obviously the LEDs are sitting a lot closer to the lip of the light than single emitter setups so the reflectors will ahve little effect on the throw. I'm assuming anyway. Probably excellent floodies, but useless in the wide open really...unless their throw is better than I suspect.


 There's definitely a well defined hotspot in the triples (check the floody buddy shootout beamshots in my triple XML thread), and plenty of brute force lumens, but a single XML in a 52mm reflector will easily out-throw 3-XML in a 52mm triflector or tri-optic.


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## moderator007 (Aug 19, 2011)

Techjunkie, thanks for the confirmation.


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## richpalm (Aug 19, 2011)

Once I saw this thread, I had to run to Walmart and get a red host to transfer one of my triples into! <g>

The Shiningbeam setup as mentioned works really well, once I was in a good enough mood to get it working. :ironic: I used Ledil MC-E reflectors; the thing gives an unbelievable wall of light and it throws well by sheer output, which I find much more useful than a laser spot.

I had to use 4 D NIMH's though to get enough current. 3 wouldn't do it... with 4 I got almost 10 amps. 

TJ, how did you get yours going with 3 cells?

Should've put this in the Everyman's thread I guess.

Rich


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## Techjunkie (Aug 20, 2011)

richpalm said:


> Once I saw this thread, I had to run to Walmart and get a red host to transfer one of my triples into! <g>
> 
> The Shiningbeam setup as mentioned works really well, once I was in a good enough mood to get it working. :ironic: I used Ledil MC-E reflectors; the thing gives an unbelievable wall of light and it throws well by sheer output, which I find much more useful than a laser spot.
> 
> ...



Rich, my recipe for success is no secret:
Lower resistance as much as possible by...
- using thick (20awg) stranded copper in the shortest lengths possible
- using de-oxit inside the mag switch and on every contact surface (springs, tailcap, tube ends, battery contacts, etc.)
- use AccuPower Evolution LSD NiMH cells. Not all LSD cells are created equally. Like Eneloops and Duraloops, the AccuPower C and D LSD cells have much lower internal resistance than competing brands.
- surface mount solder your LEDs on MCPCBs from KD. There's a thread about (no real) benefit to overdriving XML emitters where it was demonstrated that not all MCPCBs are created equally, and I've had great success with the cheap ones from KD vs. others. Alternatively, just buy preassembled LEDs on stars from KD.

You can see in this thread that my 8AA config is 4s2p, for 4.8v. The SST-90 in cool white has higher Vf than in neutral white, and even after burn-in a 3.6v NiMH pack wasn't enough. With the 4.8v "pack" the regulators have to step in to bring what would be 14A down to 8.4A. It's possible that your XMLs are just higher Vf than mine. I wish I'd made Big Red a 2-mode light, but when I built it, I didn't know about the 4-star multimode 2.8A boards. I'm not tempted to open it up and change anything now.


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