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Thread: SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)

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    Default SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)

    SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-17-2011 11:58 AM GMT

    Up for sale is a mint condition Techjunkie original. This light was originally conceived as an SST-50 super thrower when the SST-50 first hit the scene. It has recently been upgraded to CREE XM-L and WOW, what an improvement. Specs:


    • Mag 3C host, bored to fit fat 26650 cells, extended tailspring
    • CREE XM-L T6 bin, 1000+ LED Lumens from a single LED! (check XM-L datasheet for T6 bin @5A)
    • Glass lens, Mag Rebel reflector w/bottom trimmed, fixed focus
    • Dual DX 20330 drivers in parallel
    • Takes 2x 26650 cells 5.5-8.4V in
    • 5.0A delivered to LED, Clamp tested

    Below are some historical buld thread shots from when this was originally constructed with an SSR-50:





    (Business end from when it was SST-50 and I had a better camera handy)



    Business end with XM-L (current):



    1/80 sec Beamshot (current):



    For beamshot comparison to other super lights at the exact same camera settings, including Phatlight emitters in the same Rebel reflector, please see this post here. The shot above is the last photo in that post.

    Runs on two 26650 cells, not included with the light. Batteryspace 4000mAH LiMn cells are recommended for maximum runtime (of ~1.5hrs), however any two 65mm length cells capable of safely sustaining a 2-4A current draw through the discharge cycle and providing a Vin between 5.5-8.4V combined may be used. This includes but is not limited to:

    AW IMR 18650 with a sleeve

    Sony 26650VT (from a tool pack)

    A123 26650 LiFePO4 cells

    AW IMR 26500 cells with a dummy C-cell spacer and stock length spring (do not use 3 cells!)

    The light was babied as long as I owned it and as such is in pristine condition.

    Price with no batteries included, but with US shpping and insurance included is:

    $150

    International shipping and insurance will cost extra and would be calculated based on destination.

    Method of payment limited exclusively to PayPal to techjunkie (at) iname (dot) com, or to cash if transaction made locally in person.

    First I'll take it claims it, but funds are required within a week or it goes to the next person in line.

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-17-2011 12:03 PM GMT

    (Reserved)
    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Ginseng on 01-17-2011 12:45 PM GMT

    Hey Tj. Nice build. I hope you don't mind my asking how you think the LED might hold up under the 5A load. The spec sheet shows a 3A max drive current. Just an old hotwire guy trying to understand this cool world of LEDs.

    Wilkey

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by skunknuts79 on 01-17-2011 01:36 PM GMT

    Hey TJ,

    Nice light, I've read about it's history before! So, how much testing/use has the LED gotten @ 5A?

    If the LED did burn out, I'd imagine you'd help put a new one in if the buyer supplied the LED?

    So, how is the heat management? Are you confident it run a full battery cycle w/o thermal issues?

    Also, if I bought it, could you do the GITD epoxy as you had once planned? I'd prefer blue, if possible, but green is ok!

    I'll take it if the answer to the last 2 questions is 'yes!'

    Best,

    SN

    P.S. If I added some extra $, would it be possible to retroactively add a copper HS, if needed? Any other adjustments that could be made to toughen it up? Basically, it would be pretty heavily used, so I want it to be prepared for real world use!

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-17-2011 02:31 PM GMT

    Quote Originally Posted by Ginseng
    Hey Tj. Nice build. I hope you don't mind my asking how you think the LED might hold up under the 5A load. The spec sheet shows a 3A max drive current. Just an old hotwire guy trying to understand this cool world of LEDs.

    Wilkey
    Wilkey, I'm glad you asked. I'll start answering by saying that I'm not aware of any other LED that can be overdriven so far above mfg. spec., except maybe the XR-E, depending on what you consider to be "spec". What I think I've discovered here is that CREE really under spec'd the maximum capabilities of the XM-L. I'll explain why I have that impression. Wilkey, I'm glad you asked. I'll start answering by saying that I'm not aware of any other LED that can be overdriven so far above mfg. spec., except maybe the XR-E, depending on what you consider to be "spec". What I think I've discovered here is that CREE really under spec'd the maximum capabilities of the XM-L. I'll explain why I have that impression.

    When this light had a 4500K tint SST-50 in it, mounted the same way, I could visibly detect the emitter tint shift from it's nice creamy neutral white color, which it would sustain at 4.5A, to a cooler tint that seemed slightly dimmer. I documented it with photos in one of my build threads. Having replaced the SST-50 with the XM-L, I see no indication of that happening. Even after a 10 minute run and then a 30 second cool down and then back on to full blast, there is no discernable difference to my naked eye. Keep in mind that the SST-50 is actually spec'd at a maximum drive current of 5A and already in this application, the XM-L is keeping cooler than the SST-50 and showing no signs of dimming or tint shift.

    I think the answer to why CREE would not chart or even mention the XM-L running at 5A is that the XM-L does not scale nearly as well above 3A as it does below 3A. From 3-5A, the lumens per watt figure drops and the increase in light output is not as significant as increase in heat output. Also, the entire service life of the LED is, I am sure, significantly shortened from its claimed 50,000 hours (or whatever it is).

    Having said that, it's also important to observe that installed in the same fashion, the XM-L at 5A generates considerably less heat than the SST-50 at 4.5A. It is clear that unlike the SST-50, the XM-L at 5A is definitely brighter than at 4.5A. Compared to my Mag 1C cutdown with Rebel reflector, XM-L T6 and 4.2A regulator, this XM-L at 5A is noticibly brigther.

    While composing this reply, I've let the light shown here run for 40-45 minutes with a very quick 10sec stop at the 20 minute mark to change the depleted Sony 26650VT 2AH battteries (they weren't fully charged at the start). At the 40-45 minute mark I decided to shut it off because while unheld standing straight up on my desk, the neck is comfortably warm and the head is hot enough to be uncomfortable, but not unbearable to hold. Had it been in my hand the entire time, my blood might have kept it cool enough to keep going. After a minute of rest, I turned it on again for another 10-15 minutes. I'd say at this point that the LED has demonstraded withstanding terrific thermal abuse.

    Quote Originally Posted by skunknuts79
    Hey TJ,

    Nice light, I've read about it's history before! So, how much testing/use has the LED gotten @ 5A?

    If the LED did burn out, I'd imagine you'd help put a new one in if the buyer supplied the LED?

    So, how is the heat management? Are you confident it run a full battery cycle w/o thermal issues?

    Also, if I bought it, could you do the GITD epoxy as you had once planned? I'd prefer blue, if possible, but green is ok!

    I'll take it if the answer to the last 2 questions is 'yes!'

    Best,

    SN
    SN,

    Thanks for your interest! Please see note to Ginseng/Wilkey immediately above regarding testing at 5A and thermal management in this light.

    My recommendation is for this light to be used as a handheld light so the owner can monitor the heat output with his/her hands. I do not recommend leaving it on and unattended for periods of > 20 minutes to be on the safe side. (I ran it for over 40 minutes on my desk just now and the head got pretty hot. Total runtime, mostly on and unheld was ~1hr.)

    If the new owner did have the LED fail, I'd be happy to perform the replacement labor for free if the new owner assumed responsibility for the shipping both ways and the cost of the replacement parts.

    Concerning the glow, I'd rather not risk tampering with the focus by changing what's beneath the reflector. I consider the focus with the bare star and the reflective disc to be perfect at the moment and couldn't guarantee that adding a thick layer of glow infused epoxy wouldn't prop up the reflector a bit, which would require trimming the bottom more to restore focus and continue to allow the bezel to completely tighten. Also, the diameter of the hole in the bottom of the reflector would require covering the wires and screws with epoxy. If the LED ever did fail, changing a star embedded in epoxy is a pain.

    Changing the HS from brass to copper would require more effort than building a whole other light, so that's not an option here, sorry.

    I hope that doesn't change your mind.

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Ginseng on 01-17-2011 04:38 PM GMT

    Thanks for that excellent and comprehensive answer, JT. I really appreciate the time it took to pull that together. Let me ask one more question: how hard would it be to change out the emitter star? I ask because while it may be performing without tint shifting, the lumen maintenance is likely to suffer. I might want to swap the emitter at some point.

    Wilkey

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-17-2011 07:20 PM GMT

    Quote Originally Posted by Ginseng
    Thanks for that excellent and comprehensive answer, JT. I really appreciate the time it took to pull that together. Let me ask one more question: how hard would it be to change out the emitter star? I ask because while it may be performing without tint shifting, the lumen maintenance is likely to suffer. I might want to swap the emitter at some point.

    Wilkey
    Excellent question. It was designed with that in mind. The star is mounted to the heatsink with screws and thermal grease. The steps to perform a star transplant is as follows: Excellent question. It was designed with that in mind. The star is mounted to the heatsink with screws and thermal grease. The steps to perform a star transplant is as follows:

    Removal

    1. Remove bezel
    2. Remove reflector
    3. (optional) remove locking pin from head threads using forceps
    4. (optional) unscrew head
    5. Remove screws that hold star to heatsink
    6. Desolder leads from old star using 30W iron
    7. Remove old silver thermal grease from heatsink with cloth moistened with alcohol

    Replacement

    1. Apply silver thermal grease to bottom of new star
    2. Solder leads to new star in same position as old
    3. Reassemble by performing opposite of removal steps in reverse order


    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by jaybiz32 on 01-17-2011 09:54 PM GMT

    Ill Take it.

    Pm sent.

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-17-2011 10:20 PM GMT

    Quote Originally Posted by jaybiz32
    Ill Take it.

    Pm sent.
    Sold pending funds to Jaybiz32 Sold pending funds to Jaybiz32

    Re: FS: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by jaybiz32 on 01-17-2011 10:37 PM GMT

    PP sen. Can you send a link to the batteries you use and charging setup.
    Re: SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-18-2011 08:55 PM GMT

    Quote Originally Posted by jaybiz32
    PP sen. Can you send a link to the batteries you use and charging setup.
    PayPal received. Light is all packed up with USPS 2 day priority shipping label with insurance in place. I'll drop it off at an NYC post office tomorrow morning or afternoon. PayPal received. Light is all packed up with USPS 2 day priority shipping label with insurance in place. I'll drop it off at an NYC post office tomorrow morning or afternoon.

    Battery and charger links sent by PM. One note about that UltraFire WF-188 charger though: I recommend charging only one cell at a time when using it in 3.7V cell mode and set the current to 300mA. I have found that it cuts off the charge way too early when charging two 3.7V cells (max 4.2V) at the same time, and still a little too early when set to 650mA. (Maybe it's just mine. Also, I don't have those issues with LiFe cells in either 3.2V mode)

    I recommend getting a cheap digitial multimeter to test your battery voltage of each battery after charging.

    NEVER load two cells with different voltage.

    Thanks!

    Re: SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by jaybiz32 on 01-18-2011 09:31 PM GMT

    Can I use the older wf-139 charger. It only charges 3.7 Volts.
    Re: SOLD: TechJunkie's Mag Rebel XM-L @5A Regulated Super Thrower (3C sized)
    Written by Techjunkie on 01-18-2011 10:21 PM GMT

    Quote Originally Posted by jaybiz32
    Can I use the older wf-139 charger. It only charges 3.7 Volts.
    Some of the old WF-139 didn't stop charging and would kill batteries without protection PCB (like any of the cells that are compatible with this light). You need to know for sure which WF-139 you have and how it behaves to be sure. Test it with (cheaper) unprotected cells and see if it charges them past 4.2V when left with the green light on for a while. (Test frequently with a voltmeter to keep from really overcharging.) Some of the old WF-139 didn't stop charging and would kill batteries without protection PCB (like any of the cells that are compatible with this light). You need to know for sure which WF-139 you have and how it behaves to be sure. Test it with (cheaper) unprotected cells and see if it charges them past 4.2V when left with the green light on for a while. (Test frequently with a voltmeter to keep from really overcharging.)

    Charging IMR (LiMn) cells over 4.2V damages them. You don't want to leave those cells on a charger that doesn't completely cut off th charge when 4.2V is reached.
    Last edited by Techjunkie; 03-11-2011 at 05:56 PM.

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