Springs!!

Great work djozz! Hmm, really sucks to learn that your investment turned out this way.

Is there any way you can think up to do the same measurements but with all the springs compressed? When in use in the light the spring will be compressed afterall

Thanks for the work! To bad your spring didnt turn out like you had hopped.

Spring compression will vary based on “battery length” vs “battery tube length” in a use scenario so depending on what you are actually shooting for that could be a ton of measurements.

I get what djozz is demonstrating with these measurements. Offhand I don’t see where you area headed with your suggestion.

I assume that only spring compression where one coil touches the next will actually have an effect on resistance.

nice, now copper braid them and see how much of an improvement it shows please

Good review…shows that there is ALOT of loss in those springs

Thanks for the testing. When possible, I copper braid the springs even if the light was using a stock driver (ie. driven at < 3A). It’s more of a “feel good” effect on me…and also it gives me a chance to take the soldering iron out. :slight_smile: :smiley:

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.