Springs!!

On all of them? He did copper braid the worst candidate and it showed a 284.3mV improvement. Percentage wise, the copper braid has reduced the resistance by up to 95%.

Nice work djozz, thanks!

Thanks for the test!

I’m glad to see that our Beryllium Copper Spring stands out in the test, and it has met our designed requirements.

I should add some comment to the result.

First, this spring is not designed for the general use, it’s for our high power flashlight project to
minimize the resistance as much as possible, that’s why we add the note on the website.

Second, the beryllium copper material is softer than the spring steel, and has less memory,
that means it will not completely come back to the original length after compressing, regardless of half hour at 6A or not.

Third, this spring is actually produced at 6.5mm, when you compress it a bit, it will become around 5mm,
we have put the spring under 3KG weight for 10 days, and it’s still around 5mm, but if you compress it hard to the 1mm level for several times, it will be around 4mm, (not quite possible to be compressed 1mm level time to time in the flashlight tube), and it will not be less than 4mm no matter how hard you compress it.

So, when “djozz” said “intl-outdoor spring failed the test: they collapsed a bit and did not come back to their original length”, I’m not surprised at all since this is how the feature of Beryllium copper depends on it.

It might be hard for the customers to understand this features.

Thanks for the test again.

Thank you for posting this! Coincidentally, another thread poster is dealing with mechanically weak springs, which I see you also tested. It’s sad to see the best electrically are so weak mechanically.

So I think I’d want to know: Which springs are the strongest, mechanically, since the copper braid trick would then make them the best electrically?

Now I’ll go suggest your thread to the other guy.

BLF, yet again, RULEZ!!! (Of course that’s thanks to posters like you!)

Dim

i see that now…thanks

Dude, an actual documented voltage drop test, this is great!

So in general, springs take off 0.3V at 6A, that’s a whopping 1.8W power thrown away. I expected some drop but this surprises me a bit. I though it would be way less than 1W.

This sure pushes spring braiding up my mod list. I use silicone wires though, work much better as movements are involved. Pure copper braid normally break after a year.

Thankd djozz, great contribution.

I think steel springs are the go-to for mechanical strength. Maglite springs are steel. Djozz’s test backs this up, and if you’re braiding/wiring them anyway you don’t have to care about their electrical properties.

Thanks djozz.
Any plans of comparing these results with silicone wire as well? (in place of the copper braid).

Thank you for the test and for documenting the results.

Silicone wire vs. copper braid is going to depend on the length, quality, and size of copper braid used, as well as the length, quality, and size of the wire used. I imagine that the difference between copper braid and 22 AWG wire in the lengths typically seen inside of a flashlight spring is very small; however, if you use tiny wire your results won't be nearly as good.

Thanks djozz. Love your work and again an invaluable resource.

+1

Best of both worlds!!

Well your springs are still three times better than normal springs… should be worth the money.

$1 a spring still sounds ok to me, I’d take a handful.

Thanks you all for the replies, and special thanks to Hank for the elaborate explanation of the testing of the intl-outdoor spring.

I think you are right, I was a bit too negative about them, they sure have their purpose because they are a noticable upgrade for stock steel springs. I really hoped that they would be as good as a copper braided spring, but springs just do not get much better than this. The resistance is not as low as the intl-outdoor spring but much better than steel springs, and the mechanical properties are excellent.

Thinking about these alloys, (I looked it up) phosfor bronze has a conductivity of 10-20% IACS, beryllium-copper is also 10-20%IACS (all depending on the precise alloy). The intl-outdoor beryllium-copper alloy has an exceptional 45%IACS, but at some expense of the mechanical properties. So I think that the elusive beryllium-copper spring that has been the talk of BLF for a while will either be electrically not much better than my phosfor-bronze spring, or mechanically worse to some extend.

Nice work seems like this hobby is getting expensive.

Thanks Djozz for your invaluable test!

love you work and dedication!

Thanks for another very valueable test.

The becu spring is better than I thought, I have to order some…

Djozz, you da man! :)

I had hoped the nanjg105c spring was better. But now I know how that compares to the others.

Thanks for all this data!

Yeah, braiding the Nanjg 105c spring should free up ~0.068v at 6A… now I’ve just got to figure out the best way to braid/wire such a small spring. I think my normal technique involves too much solder wicking up in the copper. The spring is only what, 5mm tall?

Thanks, once again, for a job well done!

And timely too! I just ordered some of those beryllium copper springs from Hank! :slight_smile: (I say “just”, ordered em a couple of weeks ago, expecting them any day now)

Your phosphor bronze spring looks like a good one, I wouldn’t mind picking some of those up from you if you are wanting to recoup some of that test budget. :wink:

While I don’t mind soldering the 22ga wire inside a spring, I don’t like the steel springs that the solder might not stick to… releasing the bypass without my knowledge or being a “cold joint” that isn’t producing the required result. So the phosphor bronze spring would be an excellent answer, taking solder and already having a low resistance such that it wouldn’t be mandatory to do the bypass.

Nice test, finally able to “see” what’s going on there!