Waiting for the emitters from the Mountain electronics.
In the meantime, I think my stock diodes have died. At least one of them, since they are in a series… The light stopped working. The “stop” itself was rather abrupt… And it does not work with either the stock or the new driver. Is it possible that one of them, since they are on aluminum stars, cold not cope with the current from the LCK 5A driver and have died?? I recall that one of them had some dark spots back in time when it worked Is 5A too much for them when they are on aluminum stars? Is this likely to be the root of my problems or should I run some advanced diagnostics to find out what is wrong?
My leds are finally here!
I “examined” the flashlight and found out one of the stock emitters was dead. It is the one with dark spots. On the bright side the driver seems to be OK.
Hmmm, I swear I posted to this thread once. Oh well, must be gremlins or bad memory.
That stock driver is a real good 3T6 buck driver. Hang on to it. If this light could hold 4 cells, you could use it to drive the 3 emitters in series at 7 and even more amps. I'm sure you'll find a good use for it eventually. Werner has a cool post somewhere on how to piggy back an Attiny13a MCU on that driver.
Yeah, 5 amps is pretty hard on an emitter when it's on aluminum. Especially, if the aluminum base is not well connected to the host.
I think you made a good choice on 1A's for dedoming. I and others find that tint works decent for dedoming xml2's. Sure you know, but the gasoline method is the safest way. Like the gasoline gently dissolve the dome off. Much less risk of breaking a bond wire that way. I like to set the container in the sun so that heat speeds up the dissolving process. Usually takes about 2 hours that way. Just don't tightly seal the container as you don't want pressure to build to the point the container bursts.
Looking forward to seeing what you do with this light. I have one, but I won't be getting around to modding mineany time soon. Thinking I will copy Ouchy's mod, but dedome like you're thinking about doing.
There is a focal point. Positioning the emitter higher or lower hurts throw and beam quality in most reflectors. Usually, the manufacture has already taken care of that for you. I keep a variety of isolator rings and swap them until I get the best beam pattern I can. Hopefully, your stock isolators are just right already.
Some lights, like a lot of SRK's, don't even have an isolator ring. I find in those that the beam pattern improves dramatically using the above process.
OK, but the emitters are dedomed now, so it is not a stock light anymore and I am afraid this case has not been taken care of by the manufacturer. Or am I wrong?
OK, but the emitters are dedomed now, so it is not a stock light anymore and I am afraid this case has not been taken care of by the manufacturer. Or am I wrong?
You're right. The apparent light source is no longer the surface of the doom. Hopefully, someone that has more experience with dedomed xml2's and your light can answer your question. It maybe something you will have to experiment with yourself.
I would think if you do have to adjust the height, it would be to raise it because the bare emitter is lower than the top of the dome.
fellfromtree wrote:
Where do you get those rings from? Is there different thickness like a variety pack to try out and then could buy the right size
I have accumulated them over time. A variety pack would be awesome, but I don't know of any. I did get a bunch of different ones from one Aliexpress vendor in a bundle. I just searched my Aliexpress history, but it doesn't show purchases going back that far. I know Comfychair had a thread on them and that is what linked me to the bundle. I have to run. I will try to find the thread tomorrow if you don't find it before then.
Well you can… But you’ll lose some throw to spill depending on the reflector. There is a perfect spot for throw in the tests I’ve done. Kind of a squirrel here myself
I have successfully dedomed the LEDs and mounted them on the pill. I used those stock centering rings and they saved me lots of work, although I had to do some minor adjustments to make it perfectly centered. The thermal glue i used is some cheap junk from DX.com , but I mixed it with a bit of aluminum powder ( actually as much as possible until it was semi-solid to help with thermal conductivity) then I applied a thin layer of the” cheap Chinese junk with aluminum powder” on the stars, added a few drops of acetone to make it temporarily as thin and liquid as possible ( acetone evaporates fast, so it should not have any long- term effects on the strength of the connection) and put the emitters, the pill and the reflector together. I tightened those 2 screws all the way down and even put a 10 kg dumbbell on top of it to make sure only the smallest amount of the glue stays between the stars and the pill. Pics will come later, it is 01:03 am in my country and I am tired.
Sounds like great progress. So it sounds like you are waiting for the adhesive to cure and then just wire the emitters to have the top of the head completed?
You probably already have this planned, but just in case. When the head is completed, you can run some extra wire so that you can measure current to the emitters and work on your driver in the open. Kind of like this:
Not sure about that thermal adhesive, but having the emitters on copper is the most important part. I take it the aluminum powder is very fine and that like you said you made it thin with acetone and pressure. So maybe it will be very effective. I think thin (even very cheap) paste would be better if your pill and bases were flat. Testing for thermal sag will tell you if your setup is working properly.
This driver can not run xm-l2 emitters on the absolute edge, like 8 amps, so it should be fine the way it is. Time will tell. This is not a state of the art flashlight, but I tried to pay attention to all details and do it properly. I am no modding guru and don’t have equipment to really test it, I simply wanted to try out a promising idea I came up with.
I finally made it work! I did not expect such a dramatic change with dedomed xm-l2s on noctigons! I had had xm-l2s on aluminum stars from the beginning and it was , but copper stars + dedoming have finally brought this flashlight into life! It is awesome! The throw is much better and the light colour is also great. The hotspot is much smaller than it used to be and the colour is warmer, but IMHO more natural.
BTW, I said a few bad things about the International Outdoor Store. All of them true though. The first leds I ordered did not arrive, they did not communicate about a solution and it took a rather long time to get the money back. Well, my first order at them did not impress me, but I decided to give them another chance, because everyone here seemed to be satisfied with them. So I ordered some new leds and they arrived within 2 weeks. No problems with this order at all. So I hope the first order was just a bad luck on both sides and I am honestly glad the second leds arrived. That is all for now.
Hi friends, I have a question. The light is still working, the leds are OK, but the driver is a bit of a nightmare. It has no low voltage cut off and even with protected batteries I managed to overdischarge one 32650 cell into oblivion… I need another driver that is capable of delivering around 5A to 3 xm-l2 leds, but has a low voltage protection for 3s configuration and has ± 25mm wide contact board. Could you suggest something other than drivers from mountain electronics? Their shipping prices are too high.
I dont care much about modes, I only need a driver for 3 XM-L2 with one 5A or so high mode and one low mode with a 3s low voltage protection feature that does not cost an arm and a leg to be shipped to Slovakia. Any suggestions are welcome.
Thanks for your help so far!
Is 5A too much for them when they are on aluminum stars? Is this likely to be the root of my problems or should I run some advanced diagnostics to find out what is wrong?
Perfect