How-To: Add Copper Braid to Springs

THE-day, the ones you linked would need to be cut shorter, they would be unstable at that length. I would guess up to 1/2 inch or so would be OK, maybe just cut in half.

I did it on my KDC8 and my solarforceL2N tailspring thanks for posting thread on thisn I did with out any major calamities befalling me or poor light thanks again.

I like how you did this on the light i won in your give away, its one of the most powerfull single XM-L lights i have now. :slight_smile:

DenB, I received my replacement F13 that I bought a while back, after the giveaway. It was DOA… I took it all apart and put it back together. It is fine now. :~
Doesn’t matter much, since I’ll replace most of the guts with new guts.

They’re properly called “Flush Cutters”. These are made of plate steel, bent and sharpened in all the right places. At some point, at the moment you cut a wire, one of the jaws will fly off with a pop. It won’t hurt unless it hits you IN the eyeball, but it’s going to happen.

I use these at work to cut Cat5/Cat6 ethernet cable and occasionally other low-voltage copper cables. The plate-steel arms fail right at the edge of the hinge. Since it happens at the moment of greatest impact in a cut, the result is quite violent, for such a wee bit o’ metal. The flying jaw still has a sharp point and edge, but they don’t tend to fly too far so I doubt they’d stick into anything. They’re cheap enough, I don’t even bother with returning them “under warranty”, usually.

If you’ll invest in a bigger, tougher “semi-flush” cutter, it will handle all but the finest flush cuts, which will be done by this one, all of which will extend this one’s lifespan significantly.

If you take care of a good set of flush cutters, they can be a most awesome tool, regardless of the price… (try it — gently — next time you get a stuck splinter or metal shard…)

+1 on this suggestion!

Thanks relic38, after I posted I realized they weren’t the perfect size.
Well I was able to find some silver plated copper springs on an old CPF thread which are the right size.
I’m hoping there are still some left.

Btw, whats your opinion on stiff gold plated springs? Are they good enough to reduce resistance?

The stiff gold plated springs are usually steel-based. Very high resistance. The gold plating does help a, but mainly prevents rusting. After testing them, I end up putting braid on them.
Edit: I modified this statement slightly based on the test results below.

I tested what I believed to be copper alloy (possibly beryllium copper) springs that I got from Fasttech . The are definitely not steel and according to Fasttech they are made of “carobronze”, a brand of copper alloy alternative to beryllium copper. Whatever they are, they exhibit superior performance over standard steel springs that we often see on drivers and tailcaps.
I also tested similarly sized chrome-plated and gold-plated steel springs that I removed from flashlights or were on some switches I had.
All three were tested at 5A and the resulting voltage drop across the spring itself was measured. The measurement was taken after the voltage settled due to any heating of the spring.

  • Copper alloy spring: 114mV at 5A = 22.8 mOhm, no significant heating, warm to the touch.
  • Gold-plated steel spring: 301mV at 5A = 60.2 mOhm, spring got very hot and started to smell but no visible smoke.
  • Chrome plated steel spring: 680mV at 5A = 136 mOhm, spring began to smoke and melted my J-clip before I noticed and stopped the test. :expressionless:

Not exactly definitive or comprehensive, but good enough for me. These springs are only about 12-14mm tall, so not the best for every application. I used three in my Copper DIY build, and I am happy with how they work there.
Copper braid/wire can help all three types, but there is a point of diminishing returns, so I only recommend augmenting the spring types that get all hot and bothered if you do not do it.

^^Appreciate all your efforts relic!

I de-soldered the driver spring first, and then tried to solder it back with the copper braid attached......

That wasnt much fun... and it took me quite some time, and it doesnt look good, plus the copper braid got quite a bit of solder in it, so it isnt that flexible anymore... hopefully it will hold up.

Get this - for my Shocker mods, I'm like copper braid'n every freak'n spring, five, and getting good results with higher recorded amps. Well, one of my Shocker customers accidentally shorted the + to - while attempting to measure amps, I think, so, he said the lan on one end of the carrier burned up. He patch'ed it, and got it fully working! But, that got me think'n -- the weakest point of a circuit will burn up on a short, so, those lan's are the weakest point - pretty obvious? So on my latest Shocker build, I added jumper wires over the lans - there is one on each end cap on the underside - longest run lan. So I had a shocker carrier with the extra jumpers, one without - measured amps on Pana PD's with the IOS 3.5A driver (runs direct drive on a Shocker), and got 0.35A higher on the jumpered carrier (4.35 to 4.7A).

So, jumpering the lans made a real measured difference, amps correlate to lumens pretty well on XM-L2's on copper. Crap - on Samsung 20R's, I'm getting over 5 amps, over 4,500 lumens at 30 seconds, 223 kcd, without the jumpered lans - sic...

Ian? Are you talking about the battery contact points on the battery carrier?


I think he means the traces between the contact points for the cells. I know what he means because I did the same thing (shorted right inside the flashlight, smoke everywhere, scared the daylights out of me). I ended up bridging it as well.
I didn’t go back and do the others, but now I’m thinking I should.

yes. traces. You can see them by the raised surfaces. There's one short, one long on the underside of each end. I jumpered only the long ones.

Great thread fellas…lots of good info. Thanks

maybe a dumb question, but would this mod be helpful to a Sipik 68 clone? The tailcap spring is pretty small. Every little bit helps, right?

thanks!

On a small light, like the SK68, the currents are still quite high (1.5-2A). There could be a benefit to improving the resistance path. I would be concerned with using 14500 Li-Ion cells though, as I think the resistance is what keeps the driver from blowing up.
If you only use AA Alkaline or Ni-MH, go to town; Li-Ion 14500, not so sure it is safe for the driver. Only one way to find out :wink:

Thanks for posting your results. They are very encouraging. Have you had a chance to compare the FT copper alloy springs with similar beryllium copper springs? I wonder if there would be significant differences?

Last night I was messing around with resistor modding some new drivers I got for the BTU Shockers... I had one up to 7+ amps on 3 20R cells, settling down to 6.9A. The carrier springs were getting VERY hot after only a few seconds. They definitely need to be upgraded and/or supplemented with copper braid to handle that much current. I may be interested in some beryllium springs after all.

The FT copper springs do conduct well but mine have not held their shape well at all. I won't put them in lights anymore because after only a few battery changes they are pretty flattened out.

Thanks for the feedback guys. I was almost going to get the FT springs until I read RMM’s report.
This is why I love BLF.