You can’t use a button on the driver side, the tolerances will simply never be good enough to get reliable contact. A spring of some sort is required no matter what.
Most carriers hide a small high resistance spring under the carrier button but I had them use a large beefy spring on the driver side so that it could carry more current and be user serviceable / by-passable if they desired.
While a slightly taller spring would of been nice it is doing what it was designed to do and worst case you can by-pass it or add a small solder blob to the top of it if you have contact issues.
These are FAR harder if the spring was hidden under the carrier button.
Then how come it works fine for my TN42vn? Never had issue with that light and I’ve had it 3 years.Photo is several posts above.
As far as putting the solder blob and bypass. That’s great for people who know how to mod but I would say the majority of us like myself don’t. I don’t know how to do that and I should Not have to do that.
I'm not familiar with the TN42 (vn is custom), but most likely there is a spring on one side or the other, either under the brass button or on the carrier. I've got several lights with carriers, and I think all have a spring involved somewhere. It's got to be on the Batt+ or Batt- signal, so some will have a spring on the outer ring even.
Ditto, I don’t have that light but willing to bet the spring is simply under the brass button on one side. That is how the GT carrier works, they have a spring under the brass button on the carrier. Unless you take it apart you would never know it is there but it is.
It is also the weak link in the GT circuit, which is why I had them move the spring to the driver side for this light.
The tolerances to have solid brass connections on all connections and get reliable connections would be unheard of and not reliable long term in a flashlight even if it worked out of the factory. Something has to give to get a good connection.
The stock and VN version is the same in regards to the Brass button top on the positive end. I cannot see the spring but there’s a spring under there because when I press down on it releases back.
For someone who knows how to modify it, couldn’t the same thing be done with the WT90? A brass button with a spring on the other side?
huh, this is really good to know. I have the setup to do spring bypasses but never have, since I though they were almost exclusively for more amps, I didn't realize they could also help in "protecting" the spring from "heat deformity" although that makes sense. I think I'll do this. What gauge wire is recommended?
ALao, anyone beside Tom take this light head apart? Is it worth desoldering the MCPCB to de-lense the LED? Or is the tolerances between the head and the reflector too tight to make it worth it? (I though I remember reading they were tight in there )
As I explained above, this is how we did the GT and the spring under the button was the weak link. There is just not enough space under the button to allow for both the travel needed and the current flow needed so compromises had to be made. They worked but I was never completely happy with it (the latest GT4 version of the spring is far better, although it is not really a spring at all but that is off-topic).
By moving the spring to the driver it gives the room needed for a high quality thick beryllium copper spring that can handle the current.
The only issue with this setup is that the retaining ring should of been slightly shorter to give the spring more compression room or the bottom button on the carrier made the same as the top, no idea why it is different.
I took it apart before sending it to him, it is not hard to get apart but personally I would not mess with the LED, the risks are not worth the gains for me. It is an expensive and hard to get LED if you mess up.
I don’t understand all this stuff. Maybe there’s more room under the TN42? The Brass button top on positive side is certainly not a weak link for that light.It has been on Turbo 80% of the time for the 3 years plus that I have had it.
As long as the Spring in the WT90 holds up, That is all that matters.I run this light the same way and from what I read from Tom and other people it concerns me in regards to longevity of the spring and 20Amps going through it.
I know very well what "vn" means vinh at SkyLumens - he's been doing this stuff as long as I have, maybe longer. I'm familiar with his modding and services.
The overall design of the WT90 with the spring is correct, actually better having the spring exposed rather than under a brass button. The problem is that the spring compressed. As djozz mentioned, it probably compressed under a high load of amps over a period of time (maybe seconds), got heated, and then deformed. So what is the spring rated for? All springs "should" be rated for a max current. Just like an underrated wire will melt if the resistance is too high, heat is generated. I've seen spring's coating burn off as well, but yours didn't go that far.
The ratings of springs depend on their composition, thickness, etc. These springs are thick enough, but maybe fall short in composition. Or could be a one off issue on that spring, maybe not all. For my high powered lights, the first thing I do is add spring bypasses, so spring heat problems avoided, but of course I realize it shouldn't be needed here, not everyone should mod the light.
I bet it is still the weak link, being the weak link doesn’t mean it will fail, it just means it will be the first thing to fail.
Or in our case cause the largest voltage drop and thus the largest reduction in lumens.
It is simple math, the single spring on the carrier is the highest resistance part of the chain that all the current has to flow through. Thus it is the weak link. It would have to be seriously beefy to not be.
All that said, the WT90 spring was designed to handle 30A according to wildfire and I can buy that. I have tested the light on turbo until the cells were empty and it held up fine, so I don’t see it being an issue or I would not of signed off on it.
The spring was designed for 30A and based on what I saw, it sounds reasonable.
The issue is that wildfire is not used to this much current and I think they forgot to factor in the initial compression all springs experience when loaded the first few times. They will always shrink a bit and in this case it was just enough to go out of tolerances on the bottom of the carrier.
It should of been a bit taller to start with so when compressed it would of been at the correct height. This is very hard to calculate though and something you basically have to do by trial and error or experience.
Sounds like Cochise334ever issue with the compressed spring was either a fluke then? or perhaps bad from the factory? or from installation at WT? unless anyone else can confirm their spring has compressed/deformed from running the light on turbo occasionally? i pretty much only run mine on turbo and mine is not compressed and the carrier works both ways. of course flukes happen, and there was a law named after it..
Yeah, sounds like the tolerances are real close once compressed and his just ended up at the low side of the tolerances and it was enough to loose contact with the bottom of the carrier.
There are a bunch of possible options on why your spring was more compressed, it does appear to be a fluke though.
A new spring should do it.
A bypass should also fix it as it would add some extra height to the spring as well.
A small solder blob on the top of the spring should also fix it.
If you have a soldering iron adding a solder blob should be really simple, just a very small amount of solder on the top of the spring. You could practice on another cheap light/spring even.
That said I would use it as is until you need to do something, it could never compress.
Good news for you!…I think I have exhausted all questions regarding this!
The most important thing is it continues to work….even if its only one end of the carrier that is able to make contact.
I don’t know how to solder or have a soldering gun.
I will wait and see what happens. I do know someone who can solder very very well but he’s unreliable. I just show up at his door if worse comes to worse! Because sending it to somebody is not feasible or practical it costs $35 just to ship it to someone and ship it back and then I would need to pay them some money.