This is my first post but I've been browsing for a few days. I modded an SRK Digital late model clone similar to the ones found here: http://budgetlightforum.com/node/53913

I did a spring bypass with copper braid, upgraded from 26ga to 16 ga, mounted an IR3034B capable of 195 Amps (way overkill, but its what I had from an old mosfet box mod project), and I am running 4 solder topped rewrapped well used LG HG2s. I just wish I knew how to push more amperage, then I can attack the cooling problem.

This thing has what are supposed to be XML-T6s but they probably arent, all on an Alum MPCB. Thinking of cutting slots in the side for air flow, will post more pictures if requested of the PCB, bypass, and batteries. I estimate it to be around 3500-4000 lumens after the mods based on my phones lux meter, online conversion, and power draw. I would post images but google photos is being impossible at the moment.

Welcome to the forum Ferocious Bear!
That is nice work you have done on the SRK-clone. The last bit ahead is of course difficult, getting the heatsinking right; there is no 7x DTP-board available so you have to deal with the stock non-DTP one. Luckily with the load spread over 7 emitters, a DTP board is not really needed. I think that changing the leds to “real” ones will give you an extra boost, also because good quality leds perform better in high heat.

Well, technically djozz he doesn’t HAVE to deal with it, he can have a copper DTP 7x board made, for example, or he can use 7 10mm SinkPAD’s. There’s ALWAYS options…

But yes, welcome aboard Ferocious Bear!

Edit: This Sofirn SRK style 9x has a hollow tube, the aluminum MCPCB sat on a shelf for crying out loud! So I used a scrap piece of aluminum and made a heat sink for it, put a Q8 driver in it with Anduril, swapped the XM-L T6’s for 9 XM-L2’s that I found in my kit, randomly removed from other lights.

Here’s the stock board sitting in my sink…

And assembled with the stock XM-L’s lit up…

It’s decent, not altogether impressive, but the hexagonal “stop sign” center reflector got my attention and the overall layout made me just have to have one.

Just wanted to add, we do get used to new people coming in that have no prior experience with flashlights, but it’s difficult to assume whether or not they bring skills to the flashlight interest. We like to assume they don’t, but never know if they’re a Dr. or a CNC machinist…

DB Custom wrote:

Well, technically djozz he doesn’t HAVE to deal with it, he can have a copper DTP 7x board made, for example, or he can use 7 10mm SinkPAD’s. There’s ALWAYS options…

Thank you for the welcomes DB Custom and djozz! I already feel at home!

I like both ideas, modifying the PCB to include copper slugs and creating an aluminum shelf. Mine actually has 12x XML-T6 clones so I have about 25% more power I can pull with some good heat transfer. I’m wondering if my PCB is direct drive on high or not but I don’t have an oscilloscope to check.(I assume it is.). The copper slug mod on that F3X is super well done. It’d also be nice but nearly impossible to find a ready made drop in copper shelf, however it would be nice. I need to swap out my ir3034b and reroute the buttons controls.

As of right now with fully charged batteries I’m meausuring 8.35 amps at the tail cap pulling 3.5v through the emitter. so almost exactly 700ma per FXML-T6. maybe 25% more and then next Ill splurge on a BLF Q8

Ill probably post in the previously mentioned thread from 2017 to get a discussion started. Ideas everywhere because of the coffee and late night.

You can buy an BLF Q8 driver from Sofirn, about $10 I think, that would be a nice upgrade to your light.

I hope I haven’t already posted this and forgot… when the Emisar D4S was coming out I liked the MCPCB and optic that Hank made up for it (the optic from Ledil of course) So I bought a couple of each from his site and build an Eagle Eye X6 host to be a variation of the D4s, this one uses Bistro with the high current fix. The emitters are Samsung LH351D in 80 CRI 5000K variant. The copper MCPCB is re-flowed to the custom heat sink which is in turn glued into the X6 head with Arctic Alumina Thermal Adhesive. I also used an AR coated glass lens over the optic to protect the softer material. If I remember correctly it’s making 5300 lumens on a top cell (Sony VTC5A)

Build pics of the Quad X6…

Ah, should also point out that the above X6 is one of two options against a modified Q8 in my 18,000 post giveaway. (the one that ends tomorrow at noon. less than 24 hours from now.) Just saying….

How expensive was that copper bit and how much does it weight?

I’d like to know.

The Te/Cu used was approx $9 worth of bar stock, weight should be around 1/2 pound. (1” of 35mm bar is .478 pounds)

Of course, I had to machine it to fit the X6 head as well.

(what with the reduction to fit into the head and another reduction to fit the emitter shelf, as well as the holes for wires, it should be around 6 ounces. I didn’t weigh it before installation and it’s now glued in)

I have zero experience machining (does a dremel and cut off wheel or sanding barel count? ;)) I do have a ton of micro solder and reflow experience however, these SMD components are about twice the normal size I’m used to working with. I’ve got access to a rotary tool and bits, a Weller solder station, and one of the chinese reflows. Copper while super effective, is further out of reach due to cost and it work hardening during machining in my experience. I wonder if anyone has tried to use heavy gauge copper wire or even heat pipes to improvise an odd shaped shelf? Hmmmm…..

You don’t really need to.

Just get a 0,5-1mm copper sheet, cut a bit into the desired shape and size, and put it below the MCPCB for additional thermal mass.

Heck, you could even stack them using solder paste and a heatgun,

Or just get this monster of a light with a 10mm copper shelf and mod it to your liking:

http://www.enogear.com/pd.jsp?id=22#_pp=2_358

BlueSwordM wrote:

You don’t really need to.

Just get a 0,5-1mm copper sheet, cut a bit into the desired shape and size, and put it below the MCPCB for additional thermal mass.

Heck, you could even stack them using solder paste and a heatgun,

Or just get this monster of a light with a 10mm copper shelf and mod it to your liking:

http://www.enogear.com/pd.jsp?id=22#_pp=2_358

Now that’s thinking outside the box !!

Sounds like a good idea BlueSword I could also bond the copper plates with eachother using thermal grizzly liquid metal and then past between the top plate of the shelf and the emitter. Drill and tap a couple locking screws too maybe? Idk, ill have to do some more reading.

It could work yes. Solder would be better obviously, but liquid metal would work well until you get a hot air station like I recently did.

Dollar to a box of donuts it’s a brass pill in that light, not copper.

It has been reviewed, and verified that is a 10mm copper pill.

Besides, technically, since copper’s thermal mass is about the same as brass, it wouldn’t really matter in terms of heat capacity potential if it really was brass instead of the verified 10mm copper.

Although the heat dissipation would be slower, quite a bit slower in fact.

The thermal conductivity of brass is less than half of copper. It might hold similar amounts of heat once saturated, it’ll just transfer the heat slower.

What about Graphite sheet? https://m.newegg.com/products/9SIA2W07HJ7968?ignorebbr=true&nm_mc=KNC-Go...CPU+Thermal+Paste+%2f+Grease-_-9SIA2W07HJ7968&gclid=Cj0KCQjw3ebdBRC1ARIsAD8U0V5CNQAOifhjwXDWYUpPdQ37plWSGkvUpqq2aa54aaqS2INPohycNxQaAp6REALw_wcB&gclsrc=aw.ds

Also, does lead transfer heat better than indium Gallium?

Also Based on looking at numbers the graphite beats lead by 5 w/mk. Also Aluminum beats Brass, and is easier to machine/dremel. Copper wins total at around 385 w/mk, but liquid metal is almost 50 more than that of leaded solder. At 73 w/mk, vs 50 w/mk. This is all from googling out of curiosity.

It’s not only thermal conductivity which matters.

Liquid metal is better yes, but being electrically conductive, if it flows out, there is a high chance of shorting out a component. It can’t also be used to stack copper layers for obvious reasons, so can’t use it to fuse multiple copper layers if you aren’t a machinist.

Another thing is that you do not want to mix liquid metal and aluminium, at all. You have been warned.

Liquid metal is also very expensive. It’s also hard to apply. Finally, thermal performance(not thermal conductivity) is usually better with solder, unless you apply a very thin layer of liquid metal.

BlueSwordM wrote:

It’s not only thermal conductivity which matters.

Liquid metal is better yes, but being electrically conductive, if it flows out, there is a high chance of shorting out a component. It can’t also be used to stack copper layers for obvious reasons, so can’t use it to fuse multiple copper layers if you aren’t a machinist.

Another thing is that you do not want to mix liquid metal and aluminium, at all. You have been warned.

Liquid metal is also very expensive. It’s also hard to apply. Finally, thermal performance(not thermal conductivity) is usually better with solder, unless you apply a very thin layer of liquid metal.

As long as something is holding the copper layers together, like the screw holes in regular MCPCBs, of course you can use liquid metal.

It’s not hard to apply at all, just rub it around with a Q tip.

Liquid metal is literally just that, a liquid, there is no “you need to apply a thin layer” because any excess will simply be squeezed out when you tighten the MCPCB down or whatever it is.
It will always be the minimum thickness necessary.
Unlike soldering, which can cool too quickly (especially when soldering large pieces of copper) causing excessive layer thickness, cold welds, and other problems.

Liquid metal is basically solder that doesn’t harden when cool, that’s why it is so good.

Maybe I’m a bit biased because I, well, ummmm… did something bad to a friend’s PC a while back.

Yeah. Liquid metal is the best in this case. I’d still go with a hot air reflow+preheating+solder paste for the best results, for me of course.

Liquid metal , as far as I know….is Gallium, which corrodes aluminum. So if you’re applying it to copper or brass then yes it works great. Otherwise, not so much. I have some and use it sparingly on special lights.

So, proven to be copper huh, on a light they are willing to sell for $38. With the cost of copper being what it is, I’m suspicious of those findings. Nonetheless, that light does look interesting for it’s fins… I’d love to see pics of that “copper” pill.

I’m pretty much done with soldering Luxeon V’s to 3535 boards

After succesfully modding a 21700 Sofirn C8F with Luxeon V’s a few weeks back, over 5000 lumen output, after a day or so I noticed that one of the leds lost half of its die working, and so output went down with that, 4500 lumen. Can’t stand that of course so I spent a few hours last week swapping the faulty led to a new one. After assembly: again one led that only lit up half (I did not registrate if it was the new led or one of the others). I really want this mod to work, so yesterday evening another go, new led, of course also some tiny wires broke off driver, resoldered them, minuscule solder pad ripped off, created new solder pad further down the trace and fixed wire, closed head, led-minus was shorted to body because of some twisting action while screwing reflector tight, opened up, changed led-wires, closed again, all was working….except one led only half lighting up , still 4500 lumen.

The probable reason is that for one 4040 led to be reflowed correctly on these wrong 3535 pads, it has been reflowed, checked, removed, and reflowed again on average 8 times before succes, times three (it is a triple) is 24 cycles of heating up and cooling down of the board, while far from following the adviced thermal regime for reflow from the datasheet. Apart from the heat stress, it makes the solder brittle and likely less thermally conductive.

So being many hours and three expensive LuxeonV leds down, and I’m going to find new leds for this host

Post #6000!

(at the moment)

My modding vibes are so bad at the moment that I even did not manage to grab post 6000

Well done raccoon!

raccoon, nice job on modding the thread to a 6k one!

djozz wrote:

I’m pretty much done with soldering Luxeon V’s to 3535 boards …

Perhaps you could try LH351Ds?

They don’t have as low of a forward voltage of course, but they are still very good.