What did you mod today?

Thanks djozz.
Here is the aftermath.

There is black soot/carbon between the positive and ground.

After cleaning it out I saw that part of the dielectric layer was burned, leaving a cavity. I think this MCPCB is probably not usable anymore.

This is the flux paste I’m using. It says solder paste but there is no metal in it, as far as I know. I don’t use a solder paste; I just tin the pads and keep them clean with some flux.

I notice it says to clean to avoid shorts. I’ve been using this flux for years and have had a few similar instances of shorts at the LED footprint, none as serious as this one. Is there a different type of flux you guys know of that would be less likely to produce shorts?

Quick goggling shows 2 kinds of Pro’sKit soldering paste (with pix of each)… acid-free and lots of acid.

Guess which one you got?

Jaxman E1. I changed the switch leds for warm white and replaced the resistor (default 100r for 2k2). Now the LEDs are not so bright, but they can still replace the firefly mode. I also replaced the driver for FET+1 with Anduril so the switch leds have 2 levels of brightness. I left the led wires as they were and used the Anduril files for D4-219c, so the flashlight doesn’t get too hot.

Nice mod, CvP!

I could not find a with-acid variety.

My flux paste is old and filthy looking. I wonder if that has something to do with it. In any case I think I will try a new flux.

Wellp, it also says right on the tin that it’s not for ICs and such.

With: https://www.amazon.com/dp/B00CU7MYS2

Without: https://www.amazon.com/dp/B06X6CYVR4

I just bought some of this soldering flux tonight since I was running out: MG Chemicals RA Rosin Flux Paste.

I have developed a renewed appreciation for convoy S2(+)s. They are compact and the reflector is the right size for medium to close range use. I’ve recently modded a few with regulated drivers and different emitters for biking at night. I use 3A or 1.5A mode depending on the length of my ride and use different size emitters for my helmet and handlebars and whether I’m road riding or mountain biking.

Don’t pay too much attention to the tints in the image because I’ve dimmed the lights to be close in beam intensity to one another, and some of the drivers use PWM to dim while others use constant current dimming.
Top left: S2+, smooth reflector, sliced 3V XHP50.2 1D with convoy linear driver.
Tint of the sliced emitter at ~3A current is close to a cree 3D tint. At 2.95A current I measured 5.5kcd and 70lux ceiling bounce. It has a very wide and prominent corona (due to the excited side-phosphor) extending almost to the edge of the spill.
Top right: S2+, smooth reflector, LH351D 5000K 90CRI with 8x7135 driver.
At 3.03A I measured 5.7kcd and 63lux ceiling bounce. Beam hotspot is very close in size to the sliced XHP50.2. The relative output/efficiency seems impressive given that it’s 90cri.
Bottom left: S2+, smooth reflector, XPL HI 3D with 8x7135 driver.
At 3.04A I measured 12.9kcd and 60lux ceiling bounce.
Bottom right: S2, smooth reflector, 2mm^2 WF 5400K from kaidomain and convoy linear driver. I bought this hoping for a warmer tint, but to my eye it does not really look warmer than the other CW 2mm WFs I have, but it does have a noticeable purpleish tint, so I guess that is below the BBL. At first I was going to change it out, but I tried it outside and I thought it worked ok and provided good contrast.
At 2.97A I measured 23.7kcd and 50lux ceiling bounce.

So each time the emitter area halves, going from 8mm^2 to 4mm^2 to 2mm^2, the throw at the same current approximately doubles. For off-road trails I use the sliced XHP50.2 on the handlebars and the XPL HI on the helmet. The off road trails around here are typically very curvy so not as much throw is needed. I took this setup on the road (actually paved trails) and I felt I wanted more throw because of my increased speed and farther line of sight. Which is why I made the S2 with the WF.

I think those are actually the same product, and there is just a typo in the product title on amazon for the first one. The green in the second one is just a wrapper and they both have the warning about ICs. Anyway I will now heed the warning and hope another flux is better.

I like organic flux. Blue stuff that looks like washer-fluid.

Fizzes away nicely when hot solder hits, no sticky goo left over.

Sofirn C8F. 3x xp-l hi V3 3C. I wanted to use 4000k, but I didn’t have one and didn’t know what to do with these 3Cs. Driver is FET+1 with Narsil v1.3. Two amber leds on the switch.
I guess I’ll try to sell it and make another one with luxeon v2 4000k. I like the size and overall shape.

Giving a spring bypass a first try. I was going to put the wire inside the spring, but this effort proved to be impossible. The guys who can do that are Magicians. :open_mouth:
The patient is a MT09R that I’m trying to squeeze a few more lumens from. :smiling_imp:
This light gets super hot very fast. :open_mouth:
Before new springs, it was already bypassed but it was unclear the size wire, it looked to be 20 gauge.
The driver spring looked to be 22 gauge, not certain.
The two bypass wires in the battery tube were actually 18 gauge so no change needed there.
Cut the springs shorter to match factory length.
Tailcap after new Beryllium copper springs and 18 gauge bypass.
The plastic insulators were removed to allow using flat top batteries.
The driver with a new Gold plated Beryllium copper spring and 18 gauge bypass.
After all this we gained an additional 3 amps to 25 amps and total 14,290 lumens. And yes that’s a bit low lumen reading and now I’m questioning the lumen tube accuracy for high lumen lights. It is calibrated with ” maukka ” lights. So any help or advice is welcome. :slight_smile:

CNCman, a word of caution about spring bypasses. Be sure to position and size any (+) contact wire such that in the event of a failed solder joint/wire end, that you don’t short internally against (-) components. In your case, the most dangerous one is the driver wire. I would also consider rotating your battery contact board wires 180 degrees

the wire you used has very few strands so it will break relative quick
always use super flexible wire that has hundreds of strands per mm²

here 2 times 0.5mm² one is standard wire the other high flexible silicone

I was happy today!
I received some drivers from Lexel, I would finally be able to do something to break the quarantine boredom.
And so I did.

I picked my Bliztwolf BW-ET1 (e-switch, 1 or 2 AA cells) that i wanted to mode for a while. It was a light I reviewed a while ago, I took the driver out and never used it again.

I wanted to mod it to use 2 x 14500 Li-Ion cells and Anduril firmware.

So, today I received the 2S 15mm driver and took my chance.
I forgot to ask Lexel to add the switch wires, and had to add them. Small pads, but no issues.

Then I needed to do one of the trickiest parts for me, something like “piggybacking” the light, using the original driver “contact board”, that has a specific size and shape.

I had to remove the spring from the driver (I also forgot to ask to not include it :person_facepalming: ) and put the + wire back in place.
I also had soldered 2 wires onto it the original board, that would be soldered then to the driver.

After this I add to solder the e-switch and I tested the XHP50.2 (soldered onto a aluminum PCB that was from an old XML2 led :person_facepalming: ) I got from a BLF member some weeks ago.

Even without soldering it, it was working , so I consolidated the work.

To avoid contacts/shorts between the reflector and the wires’ solder, I added some tape on the back of it.

With everything mounted, I turned the light ON and…it only worked well for some seconds :zipper_mouth_face:

After powering it in Turbo, the light started to turn blue.
I immediately shut it OFF and looked to the led… It turned it ON again and it only aggravated the situation :weary:

So, what did I do wrong here? :neutral_face:
Bad led reflowing?
Too thin PCB?

Any help concerning this is helpful… Thanks in advance!
I have other mods planned with this type of Led and 2S 15mm drivers (14500 Li-Ion), so I am now thinking to order other XHP50.2 from Simon eventually.

no DTP MCPCB most likely if it was a 6V LED

I should have used the sinkpads, right? :zipper_mouth_face:

They are small so I would have problems centering them. But I learned my lesson!

Thanks for the reply! And for the drivers too :wink:

Thanks, I did not notice that. :+1:
This is the only light I own with bypassed springs. I am going to remove them this weekend because the light simply gets too hot and actually shut off after running on high for 30 seconds and then on turbo for 30 seconds. Not what I was expecting to see from this light. I measured 25 amps with 30Q’s and it gets very hot very fast on turbo, almost useless. I had given thought to water cooling it but it’s too small for that.

I added a few more photos HERE.

Red Convoy S2+ with triple sst20 FD2 on 20mm Noctigon soldered on triple pill from Kiril. FET+6+1 with bistroHD and custom modegroups, Carclo 10511, fireball red turboglow, dual BeCU springs at the tail.
It’s heavy.