Second Generation Silver Plated High Current Beryllium Copper Springs and 95+CRI SST20!

Those leds look really good, I look forward to trying them.

Blue, i’m happy about the spring changes. I agree the first batch was sometimes too big and sometimes just right. Even with the new dimensions the “just right” cases would still be good and not too small.

I do wonder though, instead of changing the height have you considered just removing a coil and letting them be wider spaced? Once compressed with the same number of coils the height change will not be very noticeable. However, if you keep the same height, remove a coil, then after the first compression they will be shorter w/ less material so possibly even lower resistance?

Can’t really do this without making the spring quite a bit smaller, or affecting mechanical properties.

Did the math using 4 active coils instead of 5(the ones that affect conductivity in a flashlight spring), and it would make the spring deformation much higher. Instead of being 1mm of plastic deformation, it could easily go at 3mm, or even higher theoretically.

Even the manufacturer warned me about it, and recommended me to stay with 5 active coils.

You can do this easily with a steel spring of thinner wire, but not with a 1mm thick BeCu spring wire.

TLDR: Tried already, but the real world consequences would be too great to consider changing the design too much.

For my use in lots of different lights, I do have to be conscious of clearances, because many of the stock springs will compress flat into the thickness of one coil because of the conical shape where these don't because they are more cylindrical shaped. So the stock springs could probably handle longer cells. Of course if I used inner bypasses, I sabotaged the collapsing down of the spring anyway.

Also these springs are mostly stiffer than typical stock springs I see. But of course, a lot of my lights are true "budget", UltraFire and other no name brands. For ZY-T11 clones I'm working on, I'm cutting the small springs down to reduce the height of the compressed state of the spring. Should reduce resistance as well.

Not suggesting any changes, just have to bare in mind this stuff.

Even with 3mm plastic deformation it puts it from 13mm to 10mm, which is right where most medium/large sized springs are at. I’m no expert though. I think only the large spring could afford to lose this much height though. I’m biased since I (will) have both though.

Similar issues here. I find I can typically use 1 Blue spring on either end but then I have to bypass a stock spring on the other end to make up for the size/compression differences. I can rarely use both a large and small spring together as is.

Yeah, that’s why there is going to be a second revision :slight_smile:

So, I’ve shipped all of the 3500k SST-20 GA3 J4, except for Lithium, since he/she didn’t send his payment yet

Hope you will love the LED as much as I do.

Also, here are the revised measurements again:

Material: Beryllium Copper C17530 38% IACS
Spring upper diameter: 4,25mm
Spring base diameter: 5,5mm
Spring thickness: 0,8mm
Spring height: 10,25mm
Total number of coils: 5
Plating: Silver electroplating

Same thing for the large spring:

Material: Beryllium Copper C17530 38% IACS
Spring upper diameter: 6,25mm
Spring base diameter: 9mm
Spring thickness: 1,0mm
Spring height: 12,25mm
Total number of coils: 5
Plating: Silver electroplating

Payment sent :wink:

Excellent. Will send it tomorrow.

Material: Beryllium Copper C17530 38% IACS
Spring upper diameter: 4,25mm
Spring base diameter: 5,5mm
Spring thickness: 0,8mm
Spring height: 10,50mm
Total number of coils: 5
Plating: Silver electroplating

Same thing for the large spring:

Material: Beryllium Copper C17530 38% IACS
Spring upper diameter: 5,0mm
Spring base diameter: 9mm
Spring thickness: 1,0mm
Spring height: 12,50mm
Total number of coils: 5
Plating: Silver electroplating

I dont see how keeping the coils and thickness the same will change the overall height much? Since the coils stack aren’t you just making it less springy and more stiff? The depth that it bottoms out wont change much will it?

Now that’s where the difference is.

By making the top spring diameter smaller, each coil’s diameter will get smaller as the delta h goes up, which will form a conical shape.

That will allow for higher spring compression, down to about 1,00-1,50mm, which will make battery fitment much easier.

Sorry if I’m changing the values constantly. I’m just inputting values in my calculator to see what could fit best.

So yeah, it is a possibility to remove a coil, but we’ll have to make the spring quite a bit smaller.

I’ll do some more calculations tomorrow to see what comes up.

Ok I redid some math.

It should be possible to reduce the number of total coils to 4 if we reduce the height by 1mm down to 12mm.

I did not take into account the 0,2mm delta between 0,8mm and 1,0mm wire, and the difference of yield strength between BeCu C17530 and C17500.

Basically, I was doing calculations with 0,8mm wire and BeCu C17500’s yield strength(for some reason…), so it should be possible to remove one coil off of the large spring and reduce the height to 12mm.

I will not be able to do this for the smaller spring though, since even if it uses BeCu C17530, the 0,8mm wire would make collapsing worse as it already is, so not really possible.

You are getting quite the spring expert here, Blue! BLF knowledge for the win! :sunglasses:

Gotta change his name into BlueSpringM LoL! :-D

^:)

I always prefer a more conical shape. You get more usable compression range and less coil binding. :wink:

Mild coil binding does have its advantage with medium compression. It allows for very low resistance using flat top cells, but not bigger cells.

I saw this problem pop up when contactcr tried to put in a 21700, and he said not only did he have a lot of difficulty putting it in, my 6,5mm bottom small spring caused a short, melting it in the process.

So, I decided to modify the spring to be more usable, which was easy.

The large spring on the other hand… well that was a lot of work yesterday to see if the spring could handle the plastic deformation, and that is still risky. 13mm is out of the question, but 12mm height could be possible.

Just waiting an answer for the manufacturer now. They have access to simulation programs that I don’t have money to pay for :slight_smile:

So I’m just now waiting for the manufacturer’s response in regards to the springs.

Also, about the LH351Ds, some slight bad news.

My contact at Future Electronics found some good very tight binned LH351Ds in the tint bins we want… but the minimum order quantity is 5000pcs, which is a bit much :wink:

So, the LH351D part of the GB is currently in limbo.

“Failure has to be an option. No important endeavor that required innovation was done without risk.” - James Cameron

“Anything worth doing is worth over-doing. Moderation is for cowards.” - Marcus Luttrell

“The best lesson I learned was to just do it. It doesn’t matter what it is, or how hard it might seem, as the ancient Greek, Plato, said, ’The beginning is the most important part of any work.” - Richard Branson

:innocent:

I am in for:

8 big springs,
8 small springs,
12 4000k SST-20
5 3500k SST-20 (if it is still possible)