How-To: Add Copper Braid to Springs

[saypat]

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!

[relic38]

@saypat

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

[FlashPilot]

@relic38

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.

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.

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?

[RMM]

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.

[ryansoh3]

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.

[Hikelite]

@FlashPilot

@relic38

I tested what I believed to be copper alloy (possibly beryllium copper) springs that I got from “Fasttech”:https://www.fasttech.com/p/1347100 . 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. 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.

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?

Phosphor bronze springs?

What is the voltage drop one the steel springs are fully compressed?

[FlashPilot]

Thanks RMM. Did you replace all the springs in a Shocker battery carrier with the FT copper springs (or just some of them)?

[RMM]

I still have some of the FT 134700 Springs if you'd like to try some. PM me and I'll get them sent your way, I just wasn't that impressed with their qualities as a spring (although they were a good conductor). As always, they could vary the quality/manufacturer from time to time so what you get when if order today may not be the same thing that I got.

I didn't replace any of the springs in the Shocker carrier, I used the FT springs on a few other personal lights back in October. I have since had to replace them all. I should have taken a picture but they were pretty flat when I took them out!

[FlashPilot]

Thank you for the kind offer… thats very considerate of you. I just put in another FT order and included a few bags of these springs. The reason I asked you how they were used was to give me an idea of the amount of compression they were subjected to. It sounds like they werent resilient enough, regardless of where they went. I might play around with a blowtorch the next time I change the oil in my car and see if I can put some more tensile in them (heat and quench in oil), but I suspect the results wont be very impressive.

Ive become pretty good at wire modding my springs, but a good copper spring would sure take a lot of the work out of high volume mods for others. Im sure you had the same idea in mind.

[RMM]

Yes I did! They were compressed pretty heavily, but almost every light I've ever worked on compresses the springs heavily, at 50-75%+ compression.

[FlashPilot]

I was considering removing coils and rebending to keep compression around 40% and about 60% on longer protected cells. I’ll play around with them once they arrive and see what I can come up with. Amazon carries a ton of beryllium springs but they cost a fortune. Nothing I could find on digikey or several other searches. Im not sure why these are so hard to come by in small quantity.

[RMM]

That may work well for you! Or...you might get lucky and get a better batch than I did (the lottery!)

[FlashPilot]

I’ll post my results once they arrive.

[Tom_E]

@RMM

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.

Wow! 6.9A in a Shocker - think I only got 6A max and at that level, the output is incredible (over 5,200 kcd with domes). You got to keep my posted on this R&D - I got 2 Shockers coming.

Not sure you mentioned it, but we need to test the Samsung 24R's... In a Super Shocker - wow, might be really nice.

[RMM]

Yep, it kind of surprised me actually. That was without any copper braided springs, etc. What I don't know is how long the driver will last at that kind of current, I think I need to get a 15+ amp toroid and maybe a few other beefier components if I have any hope of survival at that level. The driver was one of the small toroid ones from lightmalls that I had modified to give a proper low voltage warning for 3S cells, I haven't tested that yet (will hopefully get to it this weekend). What was crazy to me was that after only 1-2 minutes the actual HEAD was hot...almost too hot to hold. I've never seen that happen so fast before with a BTU. I think I'll dial it back down to 6A-6.5A and go from there.

[Tom_E]

I've gotten them warm in a short time at 6A, but it is an amazing mass size to warm up that quick. Forget-a-bout my J18 with the 9X beast driver - 30 secs and it's hot, but 7,200 lumens is pretty awesome....

[Rufusbduck]

@relic38

@saypat

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

I think you’re right Relic. I haven’t dared to put an imr 14500 in my BLF T10 for just this reason. Boost drivers go direct drive when battery voltage is above led voltage so I just use protected cells with higher internal R. Nice photo documentary by the way, well done. If one is going to use those brass caps it would be better to solder the wick to it rather than the top of the spring though.

[unknown00101]

6.9A Jesus. That thing must turn red hot after a few minutes… If there’s any battery charge left!

[relic38]

I see mention of the copper alloy springs from FT, and if I tested them. I think they are the same, so they are good conductors, but not super strong springs. I prefer them where short travel is needed (single cell lights). They are not great for more than one cell in series, so I would move to a longer steel spring and copper braid/wire it.
RBD, yeah, I have fried those AA/14500 drivers by reducing resistance and using unprotected cells. Usually end up as one mode, bright, and no longer accepting AA cells

[MRsDNF]

If these are the springs in question I used one in the last giveaway light that OL won. I concur with what relic38 said above. They were very easy to bend around and did not have a lot of spring in them. In the light I used it in I believe it will be fine as it only used a single 16340 at low current.