Thanks for sharing.
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Have any lux readings (before and after) been done for this mod ? To see what if any gains are made. Seems like eliminating the resistance would give a slightly better current rating on a multimeter, (more accurate) but is there an actual benefit that can be measured otf ?
Gains at the lux meter will depend on the driver. If it is an unregulated driver, then there are gains to be had. Otherwise, the gains are mainly to runtime and efficiency.
Edit: I’ve had significant gains on unregulated (DD) drivers by making this mod. On an East-092 driver in an HD2010, the current jumps a lot.
Thanks for the great write-up Relic!
With plunger/nub equipped tail assemblies, Ive been spreading and flattening the braid at the top of the spring before folding it over to increase the surface contact area and keep pressures symmetrical. No solder required on that end before I slip the brass plunger over the top. Protected in dielectric grease, so far no hints of galvanic corrosion (brass/steel/gold plate/copper contact).
People with the HD defiant lights should take heed for max lumens!… hint, hint… :bigsmile:
Great post. I wish I run into it when I first started modding, it would have saved me a lot of time. I got a roll of copper braid when I bought my soldering station. Just a weller but it does the job. I bought it used and he threw in a bunch of stuff. I never knew what the heck that stuff was for until somebody mentioned it. I just managed to go through what was left of the roll and need to buy more. Where do you buy yours from? Or should I say who sells it the cheapest?
Very nice “how-to” relic38!
Thanks for sharing!
I don’t know if it’s the cheapeast, but FT sells some:
http://www.fasttech.com/search?solder%20wick
Also, you can get it on Amazon:
Jim
Cool thanks.
Thanks Relic. I’ve been waiting for this. Since you’ve been tardy in your “how to” postings I had to figure it out myself. Fortunately, I seem to have done it correctly.
A couple of times I folded a piece of braid in half, soldered the vee to the base and the two ends on opposite sides of the spring at the top. I don’t know if it helps, but it can’t hurt.
Great explanation, appreciate it!
EDIT: Is it safe to assume then with this lower resistance there will be less heat no matter how little?
After an XM-L2 or XP-G2 copper star upgrade, I put a lot in the light box, remove the tailcap, jumper the neg. batt to the host with a heavy gauge wire, check the reading. Then, assemble it with the stock tailcap, take a reading. Most lights of single cell, nanjg driver of 3.5A or higher variety will read lower with the stock tailcap and will benefit in lumens from this mod. Usually I get almost all the lumens back from the mod.
Sounds definitive to me.
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Do you recall the percentage of increase?
Regarding heat reduction, potentially. To many factors to be sure. One thing is for sure, there is less heat in the tailcap end which increases the chances of that energy being dissipated by the emitter.
good info. phenomenal pics. nice job.
Brian
Well it all depends on the light and the build, I believe, ex: 3.5A vs. 4.5A for example - greater loss in the 4.5A build. In a SS T13, I saw no loss, but that could be because how the buck driver works - I didn't do the copper braid because I saw no benefit, but maybe it would increase the battery runtime.
Update 06/25: Last night I saw just under 1,100 lumens with a suspect broken copper braid tailcap (didn't confirm yet), replaced with a good wired tailcap and got 1,234 lumens, so on this C8 heavily modded light, it was about 12%.
Thanks for this. I tried it for the first time today, and I let the solder creep too far along the wick, which resulted in the spring being much less springy.
I liked using nail clippers to trim the wick. It cut the wick without fraying and cleanly trimmed the wick flush with the top of the spring.
Nail cutters work, but I recommend these very low cost side cutters.
https://www.fasttech.com/products/0/10003258/1243300-plato-170-flush-cutter
I’ve had them for about three months now and still like new. I’ve even trimmed sinkPADS with them.
Use only on copper, not steel or brass.
I've got a couple of broken solder braids, but think it's always because of solder creeping up the braid, leaving a small length of flexible section, then it easily tears apart with compression of the spring. I've been soaking the braid pieces in acetone now to fully remove the flux, then isopropyl to clean, then don't keep the iron on the braid ends too long.
That’s good. It’s something I would like to try soon.
The GootWick I have is flux-free, which is perfect for this use.
In the light I just built for O-L’s challenge the Q-Lite 3.04A driver I used had the short hard spring. I replaced it with a steel spring, upside down. When my AW IMR14500 came in I was surprised at the low amp reading I got, so I soldered a 22ga copper wire inside the spring and found another 670mA of power! So now it’s running 2.82A and all is well!
I usually go through the center of the spring and solder the wire to the contact board right in the middle, inside the circle of the spring. Then I solder the top of the wire inside the top hoop, so that no wire is above the coil. Not really necessary to leave any slack in the wire/braid as the spring is as long as it’s going to get, it will only compress. That being said, I do like to add a bit of a coil to the copper wire just in case. 
Thanks for the pics relic, whether or not we do it the same way the end result is more Powah!! 
Edit: It’s not necessary to rush out and buy wick braid material. The copper braid around a television cable that works as a ground will work just fine, or a thin copper wire with or without the insulation. Probably the determining factor is figuring out just how much compression is on that particular spring when the light is assembled. If the spring isn’t getting squashed down very far, a simple wire works just fine.