Well guess this is my first post! I just discovered flash light mods and got my first light about a month ago. Who knew this could be so much fun!
I picked up a cheap zooming Ultrafire Cree LED light with a 18650 cell for like $5 at newegg. I figured the output was way under the rated spec since it was saying 1000l….
Anyhow I’ve take it completely apart. It looks like I’ll somewhat be able to mod it. I’ve got both a Cree XM-l2 U2 light on the way which I might save for a WF-502b build…and a new 20mm driver. Thing is the new driver is a 3amp driver…after reading up on the forum’s I highly doubt I’ll be able to run a full 3A on this tiny light. The aluminum drop-in pill is by no means a “drop-in” and it screws into the shell. The emitter does look to be a XM-l T6 LED… so I’m hoping I can just desolder some of the 7135 units to lower the amperage delivery right? I mean with as small of a flash light with hardly any cooling, I can’t drive 3A into the LED right?
I don’t have my multimeter set up to measure this knockoff driver it came with but I did get a 2.83V voltage with it at 100%. Not sure what that equates to in terms of amperage.
I’m hoping to get my first WF-502b flash light over the holidays and also a full 2800mA driver along with a XM-L2. Whats the consensus on aspherecal lens’s?
Well I’m not an expert in these regards. But I have put 3 amps into one of these types of lights. (I’m guessing, but they are all pretty much the same.) however, I did use a direct thermal path mcpcb. This is usually recommend when current is above 2-2.5amps. The light will get hot, but it should be ok.
I wouldn’t worry about desoldering any 7135s unless you really want to be able to run the light on it’s highest mode for extended periods. Many hot rod builds here are not intended for anything but short bursts on highest output.
I think the most important thing to start with is LightRider’s recommendation, get LEDs mounted on copper MCPCBs. Start looking at LEDs on Noctigon MCPCBS. You can get them at Mountain Electronics (run by user BLF user RMM): http://www.mtnelectronics.com/index.php?route=product/category&path=60_61
Them stock LEDs on small alu MCPCBs from those cheapo lights might not last very long at 2.8 amps, but with LEDs on copper MCPCBs you should be able to run at 3 amps for a while. If you get get the heat from the LED over to the host, then you will be able to feel when it get’s hot. With a small alu MCPCB in a hollow pill, chances are that the LED will have fried before you feel any heat.
I’ll probably keep the XM T6 on this build and save the XM-l2 for my WF-502b build….
SO you’re saying I can load a full 3A on this tiny flashlight? lol I’ll definitely add some thermal paste between the PCB and pill insert along with the threads for the pill….
Are there any internal replacement parts I could use or is this pretty much it? I’d like to get a much better drop in style of holder for the driver and led but not sure…
WF-502b uses a P60 drop-in, they take a 16mm LED and a 17mm driver (from memory).
Chances are that the LED you have is a fake at that price, so I’d fit the 3amp driver, see how long it lasts.
Well at this point my only reasoning to keep this host is the zoom function… WF-502’s can’t zoom correct? I’m also surprised how the reflector on this has absolutely no shine to it… Maybe polishing and buffing that to a mirror would help?
I believe the inside diameter of the pill insert is 17mm… I’m hoping at this point I can use some thick strip aluminum that I have lying around to make a backing for the emitter and compress that against the inner walls of the pill so it will act as a heat dissipator. I’ve got some thermal tape lying around also… I might see if I can add a strip around the insert to use the host has an additional heatsink…
I’m still debating if its going to be worth all this work or should I just spend a little extra $$ and get the WF-502b…
I’ve messed with a couple of these lights. When you put thermal paste on the star, make it as thin as you can possibly get it. More is not better in this case.
On this light, the threads are in the electrical path. If you plan on putting thermal paste on the threads(which might not be a bad idea), make sure that the lip of the pill that butts up to the body is clean from any paste. Maybe even put some contact grease on that part. Then tighten the pill into the body as tight as you can get it to make sure there is good electrical contact. Alternatively you can use contact grease on the threads as well. Instead of thermal paste. It’s not as thermally conductive as thermal paste but I’ve found it works better than nothing.
Like ecotac said, it looks like you may have an xml clone. The Chinese have gotten very good at cloning and some of their clones in these lights are not that bad. However, they will typically be less efficient, less bright, and more “blue” than a genuine emitter. So, ya, put it in there at 3amps and see how it does. If it fries, order an xpl v6 on noctigon(a direct thermal path mcpcb). This DTP mcpcb is more important than you would think. It makes a big difference on lights above 2amps and essential on lights above 3amps. Your LED will definitely run cooler no matter the flashlight size, and therefor it will be brighter. Leds dim significantly as they get hotter.
I can’t see the inside of the pill, where the emitter PCB sits. Is it a solid shelf or is it bored completely through? Either way, I think this could be made into a useable light…
That “reflector” isn’t a reflector, it’s just a retaining ring to hold the light in place. You don’t want it to be polished, as that would just add reflections around your hotspot and make a really messy beam. The same is true in any aspheric-type light. My preference is to remove the retaining ring and paint with a flat black spray paint. Everything you can do to cut down reflections inside the head helps make the beam cleaner.
I also can’t tell from your photo, but that looks like it could be a junk counterfeit emitter. A genuine Cree will likely serve you much better…
Oh ya. I was assuming the led shelf was solid. It’s actually not as big of a problem as you would think, but if you want to make a shelf for it, you can use 3-4 pre1982 pennies soldered together and pressfit in. Each pil is different, but I’ve had a number of pills that held the pennies perfectly.
It’s a completely hollow pill and the shelf for the emitter is TINY! It will barely touch the edges of the emitter. Just enough for it to hold in place and that’s it.
I figured the emitter was fake…for a $5 flashlight…yea…
I’ve also considered packing down with a dowel rod aluminum foil inside the pill to fill the void… I figured that won’t work very well since the tiny gaps will provide areas for air and basically act more as an insulator. I’ve built computers so I know a thing or two about cooling. Unfortunately the pill gap between the retainer and emitter is too short for me to place anything thicker than maybe 1mm underneither the emitter to properly cool it. I was hoping the aluminum I’ll be adding to the 17mm gap will press fit into the space and be flush against the shelf.
Ok so I think I’ll stick to this build… primarily because of the 2 o-ring design!
I didn’t know the retainer was not acting as a reflector in this case… I get a pretty strong beam at any zoom angle so it’s actually a decent flashlight.
So for the driver…
It comes with 8 7135 modules on a 20mm board. That should technically deliver around 2800mA correct? That’s going to be probably too much for my driver to handle with that type of pill and lack of cooling… so I’m thinking it might be best to desolder 2 modules and take it down to say 2100mA??? With an XM-L2 if its genuine I should get around 800l…
I’ll start work on this aluminum insert in the pill. I’ll update this weekend on my progress!
That new pic definitely looks like a particularly poor counterfeit of the XM-L.
Sounds like it could even be the same driver. I would stick with the full power.
My suggestion is to firmly seat the emitter on the board on the pill, well adhered in place with thermal adhesive, and solder the driver wires in place on the LED PCB. Make sure any remaining holes are plugged; I use hot glue for this, as it’s easy to remove afterward. Mix some JB weld. You can either use it straight, or cut it with some Isopropyl alcohol. Without the alcohol, it will be permanent, but with the alcohol, it cures slightly rubbery, and can be removed with some effort. The alcohol also helps it flow so it fills the area more smoothly. Put a small amount of the epoxy into the pill from the bottom, so that it forms a shelf as thick as needed under the emitter, directly against the exposed base of the PCB. Make sure there is enough room in the pill to coil the remaining wires leading to the driver. Let this cure, and it will help with heat sinking. Although it’s very poor compared to a solid metal path, it’s better than air on a bare PCB.
I agree. Go full power:)
That pill looks like it will perfectly hold a few pennies behind the emitter. Sand the top one smooth and I little sanding between pennies. You can solder the pennies together using a torch or by placing them on a piece of wood and using a large tip on your soldering iron. Then pound/press them into the pill. This will work much better than aluminum foil.
And don’t worry about “defacing” currency. I’ve looked into it thoroughly and though some will disagree, it is not illegal.
Anyway I still agree, go full power:) by the way, the light in the link above is an sk98 zoomie and it does 3.8amps. After a couple minutes on high it gets hot enough to want to turn it down to medium, but it is a very usable light.
Oh I like this idea! I’ve worked with computers so much I haven’t really got in touch with my DIY side so much… JB weld was one of my specialties back in the day when Snowmaking was my other hobby. How’s this sound? I know JB weld is probably going to be terrible when considering thermal transfer properties but its going to be a heck of alot better than open air… I think I’ll fill most of the pill with JB weld and make a flat surface for the emitter. I’ll use some coffee straws to make holes for the wires and some thermal paste onto the aluminum pill and JB weld to ensure proper thermal transfer…. oh yea… This is gonna be sweet(in the Chrisfix voice).
No thermal paste on the JB Weld… It cures flat against the base of the emitter and extra paste would just interfere.
Coffee straws sounds like a good idea… I had trouble before when I tried to do that myself, but I didn’t think of coffee straws. I never drink coffee, so the straws aren’t something I keep in mind.
Well straight on with the emitter out of the housing I get temps upto 92C which is nuts at full brightness. With the cap and retainer screwed in, I get 55C. lol…big difference. And that’s with minimal contact with the pill. Some JB weld to create a backing in the pill and thermal paste is going to do wonders for temps…I’m actually optimistic for this mod.
I’m also planning on lapping the emitter pcb base which will help with thermal transfer. It also depends how flat I can get the JB weld to be against the aluminum…
So for the retaining cap that’s “Bronze” in color… I shouldn’t make that reflective at all??? Even if I get it really shiny its not going to help the overall throw of the light toward the lens?
I’ve got 2 emitters coming in the next 3-4 weeks. 1 is a XM-L2 U3 supposedly and the other is the U2 variant.
I just confirmed from the battery to the driver I have a current of 0.95A or 950mAh at full brightness…lol how sad. Still not sure if a full 3A is the way to go…even if I get double…~2100mAh is going to be a huge upgrade….lol
55c on high at the emitter is very low compared to most lights discussed here. 60c is an industry standard that is said to be the point at which heat is dangerous to the skin when held for more than 5 seconds. For Example: exposed water pipes that exceed 60c are required to be covered. also emitter temperature inside the light can get well over 100c without damage. 150c is what the data sheet says for Cree at least. The main concern is the body of the light to be held. The highest temps are for you to decide there.
You should pack in the jb weld while the pcb base is in position.
Yes, blacken the retainer with a sharpie or high temp black paint. You will get a nicer beam. If you don’t care about the beam, you can shin the retainer and it will give you a bit more total light when in flood mode.
Nice emitters
.95amps is quite low for a 3amp driver. There might be something wrong? Or your test leads are really thin? Or your battery is very week?
