Group Buy: TERMINATED by Niwalker

I have one concern….isn’t the starting price of the XML2 version lower by about $20 to $35?

$20 at retail but the wholesale price difference was only a few dollars and not worth trying to maintain separate codes and minimum purchase levels. Equalizing the price keeps it clean and simple and still offers a great price for the end user.

Will you be ordering from China or do you have stock with you in the US? Reason I ask is that I would prefer them to ship from China to me as it’s much closer and I wouldnt have to pay exorbitant USPS prices :smiley:

I understand and would prefer to do that way as well, but unfortunately they were not interested in a manufacturer supported GB. They will not/do not drop ship. I have to place the bulk order and then reship.

I'm curious - selfbuilt said it was a larger reflector than the TN31 - the diameter of the bezel is 1mm more than the TN31 according to the specs (79 vs. 80), but it looks like there's more on the outside rim to make up that 1 mm, so is the reflector interior actually bigger?

It sounds and looks like it's the same OEM making this, as the TN31, as the SupBeam K40, but this has an advantage with the 4 cells. I'm confused - I don't see this with an XM-L2 out throwing a TN31, maybe, but doubtful, and with an MT-G2, far worse, though it will put out a lot of lumens bridging the resistors as usual, as with the TN31 and K40.

vinh - can you please be more specific? Why are you referring to a SinkPAD? Why would you replace a superior copper star with a thinner, smaller SinkPAD?The listing of mods above are a very generic list -- I'm confused.

I emailed Vinh your questions to make sure he saw them. Just to make sure everyone is clear, the mod is optional and not tied to the GB price.

Ok - thanx! I think others will be asking the same thing, so that's good. I know vinh has mentioned SinkPAD's before, but maybe he is just referring to copper stars and using the word "sinkpad" to denote that.

Agreed! Best to clear up any questions before ordering. It will save many headaches down the road.

Another question that came up…there is not a order limit or cap at this time. 10 units is the minimum order quantity needed to offer the GB price and not the maximum number of units offered.

In the Solarforce light, the copper pcb was not a true one. It had a dielectric layer under the emitter. So I put a Noctigon in it, and did some tweaking to the driver for an estimated 4.86A to the emitter. It’ pretty dang sweet! While not throwing a “beam” of light, it puts light on a building 610 yds away.

Interests me that the MT-G2 is being said to “throw”. With 72 small dies making up the larger die surface, can it throw? Regardless of reflector? My reflector measures 71mm inside the bezel. Not much of a difference. De-doming the MT-G2 pretty much ruins it’s gorgeous tint, in my humble opinion. And I have yet to hear of anyone successfully doing it such that the phosphor stays on all those 72 dies. I really would like to see it done and see what it can do in that regard. So far, the general consensus is that de-doming makes it COOL instead of warming it. I’m not stating facts here folks, this is jut what I’ve been seeing. I can say that the one I de-domed did not take it kindly.

I’d love to see results of this work, hopefully before the group buy timeline runs out. Might end up doing some digging for moolah my own self…

<——-the MT-G2 at ~3030 lumens

Just a guess, since I have not seen the TN31 or K40 in person but this is the deepest single LED reflector I have seen. Even more so than the PowerTac X3000 and Thunderbolt. I suspect based on this alone, Niwalker decided to market it as more of a throw MTG2. I also suspect the claim is meant to be relative to other multi cell single emitter MTG2 lights, not true throwers.

So the reflector is more than some 80mm deep?

Ok this is not meant to be super precise, as I did not disassemble the light, but low end estimate is 76 MM to the high end at 88 MM.

I've tested the TN31 copper stars and the K40, and seem to be direct thermal path - both have thermal pads on the surface that test positively for continuity to the base. I've also got one of vinh's modified TN31's he said he did the sinkpad mod to, but it has the same large, stock copper star, so I think he's referring to the mod as a generic mod, in general he'd swap out for a SinkPAD but not if the stock is as good or better.

The important dimension for throw is width -- this is the major factor, but there are other minor factors. Dr. Jones wrote this up as did others with much better knowledge of optics than me, so absolute #1 factor is width, depth will reduce the spill area, maybe help slightly with throw, but not much, if at all.

For lumens, its funny -- I just measured 1,142 lumens @30 secs on a Convoy S3 EDC at 3.5A with XM-L2 U2 1A on a Noctigon. So this little tiny reflector can produce that - no throw, of course... Smile

The S2200 is $136. 5 1ohm resistors cost about $3.00. I’m getting about 2780 lumens. I’m good.

Thanks for the group buy on behalf of those still on the fence, I’m sure there will be some delighted flashaholics this time next month!

Ok, no problem with that. Thanks

In the MTG-2 version, leaving the dome on after all the mods, how much lumens will the increase be? And what about the CD increase?

Selfbuilt does actually say that the reflector on the Niwalker is deeper.

Clearly, the BK-series is using a large reflector – it's one of the deepest ones I've seen, in fact. Overall dimensions and appearance are again very similar to the Thrunite TN31, but the BK-FA01 is actually slightly deeper. For an equivalent drive level, I expect it should have at least as good (if not better) throw than the XM-L2 version of the TN31.

Now while width of the reflector is the bigger factor to producing a thrower, the depth, and shape also matter. Based on what I've observed, the increased depth helps to concentrate the beam more.

The Armytek Barracuda, and Crelant 7G5CS for example (both lights I used to own) had almost identically wide reflectors. The Barracuda has much better throw.

All of that said if throw is what you're after, the MTG2 is not the right LED for that. The XML version of the light, stock no mods, has more than double the throw.

Still, compared to most flashlights, and certainly multiemmiter lights, it is a thrower.

My hope for the light is that with a boost from Vinh it will gain a bit throw simply through added power, and it will make for an overall more practical light.

What I am absolutely torn on, is whether to ask Vinh to dedome it, or leave the dome on.

I used to the term sinkpad as heat sink nowaday. I forgot that sinkpad is a brand. What else are you confused about from the list below?

*Direct copper bonding.
*New permanent thermal adhesive from copper sinkpad to host.
*Upgrade larger wires where needed.
*Upgrade High stiffness low resistance springs where needed.
*Touch up poor connection where needed.
*Tune for best beam focus.
*Lube O-Rings where needed.
*Dedome LED for extra throw.
*Current boost to the max while keeping reliability and Factory UI.

I am having the same dilemma…at moment I am leaning towards dome on.

For the MTG2 I greatly prefer Dedome for the extra throw. Plus I like the tint. No experience with XML2 version so I don’t know.