Convoy metal switch discussion

I like the way this is headed. It would be really nice if the solution is just making that lip of rubber bigger so it makes a better seal and while he’s at it switch the material to clear or translucent instead of black so a light up switch will shine through. I actually like the idea of just a glow coming from the gap in the switch. That would look pretty sweet. You could easily color match the LED for the red, blue and green versions. Thanks all for your input. Keep it coming. In the mean time I’m probably going to be brave and take my switch apart so I can see and understand better if it would be that easy. If there is enough space it seems that rubber lip or whatever else you want to call it should be extended out to the same diameter as the washer so that it seals against the inner ledge inside the tail. If there isn’t room right now Simon could just take the inner shelf of the tail maybe 0.5mm or so deeper and then there would be room to compress that gasket (which will now hopefully be made from translucent silicone) and make a proper seal. Does that sound right?

Good question. Like this:

I had gently pulled at that join before but didn’t really investigate it closely yet. I should have. The top edge of that gasket is going to be another weak point for water ingress I think. Wonder if it could be sealed/glued using some sort of adhesive. I’m sure something like an rtv silicone would work well for the job but I’m not sure it can be done at the factory in a cost-effective manner.

Hmm, well that seems less than ideal for waterproofing. :~
I suppose if it’s tight it could be good enough. But I’m thinking Simon should consider switching to a design like TK posted?

I do have some concern about long term wear with the design she posted. Could there be a risk of edges of the white clicky switch actuator cutting into the rubber gasket over time?

I think gasket should have a little nub inside which could keep the edges of the clicky actuator away. Like the nub inside our standard rubber tailcaps.

The BLF Ti light that Rey designed also has a waterproof metal clicky design. There have been problems with getting it assembled, but that is because the dimensions are not tweeked to perfection, the principle design is good. it uses a common 14mm silicon boot cap under the metal part that is screwed down, not unlike the CNQG brass 18650 light above. I got my BLF-Ti tail assembled alright and it works very well now.

From what I understand of metal switches there is always more concern over eventual breakdown because of the additional number of rubber against metal moving parts. That said, I think if properly executed you could expect at least close to the lifespan of a traditional rubber switch. I think you have to make at least a small concession there if you want the pretty metal switch…

Getting back to the concern about water getting in at the top where the rubber gasket rests in the innermost diameter, does it really matter if it is properly sealed at the bottom which is the main trouble spot for water getting into the light? My thought on that is the upper portion of the”seal” is basically just cosmetic as far as waterproofing (secondary function being to help add springiness to push the switch piston back up) and it’s the lower seal point we should be concerned about. Yes? No?

I haven’t used one of the brass lights, but just looking at it that design doesn’t seem like it would give as nice of a feel as the current convoy design does. It seems having the metal nub part just loose would feel wobbly. TK, can you (or anyone else) comment on that?

I haven’t used the brass light either although I do have one on order from CNQG. Tracking is already working but it still reads like the package is still in China. Still should be well enough ahead of the holiday that I can avoid that delay, I hope.

I do have the Rey Ti host that djozz mentioned. Here’s a photo of that tailcap from the outside:

I can disassemble it again and get some interior pictures if you all think it would help, but that thing was very fiddly to get all lined up properly. It definitely doesn’t just go together like this Convoy switch does and I had to work at it to make it operate smoothly. Its nice once its right, but getting it right was not easy.

Like djozz says, it’s got a full rubber boot under the metal switch so it would probably be a lot more waterproof, but I really can’t remember at the moment how well that rubber boot is sealed to the host. I do know the host itself was just an empty tube with some threaded sections. This photo was made from the head but you can see all the way through:

The silicon boot of the BLF-Ti is pressed tight between the stock switch (or the switch washer if you changed the switch out for a standard Omten on a 16mm switch board) and the (from the outside) screwed-in metal button-sleeve. In principle water could seep along the inner threading of the battery tube but I expect that the compressed silicon is pushed to the side sufficiently to obtain a proper seal.

Just gonna share some ideas on how Thrunite T10 can get better than ipx8 waterproof standards with thin “easy to tear” silicone boot

Just simple sandwich is enough to get things tight





the thin boot is sandwiched between the body’s lip and a washer for the retainer ring to press on.

hope it helps

The CNQG design actually feels pretty nice. It all depends on how you do it though. Overall I’d say the S2+ design feels nicest, followed by the CNQG brass light, then the Thrunite T10T, then the Rey Ti (which can bind, unfortunately), then the Sinner Cypreus (only because it’s kind of loose), then the BLF-348 (extra-loose).

It seems to depend on tolerances, mostly.

I used my Rey Ti in the rain once, and it spazzed out. I had to take it apart and let it dry before using it again.

Then again, I also had to cut the rubber boot to fit.

First post, but been a lurker for some years. Excellent forum you all have here.
If the bottom of the piston below the boot attachment point were threaded, probably smaller than diameter of boot seal opening to protect seal surface from the threads, then the piston could have a sealing lip/flange screwed on to the bottom to tighten down the boot seal against the bottom of the piston button from the inside of the boot.

That’s a great suggestion. Welcome to the forum!

Now that’s a great first post! Welcome friend. I lurked for a few years myself then finally I just had too much to talk about! :bigsmile: I need a few minutes to wrap my brain around your suggestion but it sounds good.

Im sure that Red Rubber grease together with the rubber seal and some other’s will prevent the water coming in.

The number of place’s it’s used on car’s in far more extreme conditions! There’s water, salt, cold, heat, dirt and other things to contend with, in locations like the car suspension, steering rack, driveshafts etc.

In all of these places rubber boot’s are used to seal and to prevent the ingres of water and dirt which would cause havoc with expensive bearings and splines, various greases are used depending on the application.

I couldn’t find the switch on Simon’s Convoy shop the other day, I don’t mind purchasing one and trying it out, I have plenty of grease.

The testing of the light would have to follow real life conditions if possible but accelerated to save time, in water and out, in water and out, back in the house where it’s warm, in the fridge, back outside, switched on for a while. Back home, in the water again, hydrostatic tests - varying the depth of water to arm’s length or so.

In reality it may not be subjected to such extreme conditions but most product testing is done to failure which will give the parameters for normal every day use.

When you’re designing a crane etc its called the factor of safety, max capacity before failure( ultimate tensile strength) / working stress = factor of safety.

Factors of safety ( low) industrial engineers, high ( high) member’s of the public.

●●●●The above is straightforward, testing a flashlight seal is very simple indeed. ●●●

Put it through a cycle but accelerate this over a shorter period, know one would want to wait a year or two for the result. Nearly all product testing is accomplished like this.

More than one switch or just the rubber boot would be needed just in case it does fail so the test can be continued.

Someone else can do it or I don’t mind, in reality it’s all very very simple!

Ordering anything from Simon is going to have to wait a week. There is a good reason though.

Convoy is expanding a bit and moving to a bigger factory so right now this is the home page of the Convoy store.

Ok

I'm still new on here got and carried away with the above, I'll just let you and Simon do it as you all know massively more about flashlights than I do.

Using the grease, just one idea.

I don’t think you got carried away at all. Have you seen how much I talk? :D. You put plenty of thought into what you had to say. This thread in particular is all about ideas. All are welcome and I appreciate yours. Keep them coming. BLF is a giant think-tank for the flashlight world. Not every idea will see production but tossing all these different ideas around and seeing so many different perspectives is one of the main reasons I enjoy this forum so much. :beer: :beer: I had those mugs filled at Fuggles just for you. :wink: Cheers!

Okay so I finally broke down tonight and decided that I had to take one of these metal switches apart to fully understand all the ideas that were presented here and the tolerances involved and ideas to solve the not-quite-waterproof design. I now understand why just extending the flare/lip of the rubber boot under the plunger and against the flange/shelf isn’t enough by itself. I think I have a pretty solid idea on how to make the whole thing work but I’m not great at describing what I am picturing. I’m going to try to model it or draw it. It’s really unfortunate that Simon didn’t have a CAD model for me on this one. I was a CAD designer for over 15 years so it’s much easier for me to visualize things in that format. What I have in mind is a combination of ideas and examples/pictures posted here. I’ll try to work on that over the next few days but in the mean time keep the ideas rolling in. Thank you all for your input. This is brainstorming so there are no bad ideas… just ideas. More is always better. And I for the record Andrew, I do not consider myself to know more than you or anyone here. 50% of the people on this forum know 150% more than I will even know about flashlight building, modding, etc. I am just enjoying the ride and happy to be contributing what I can. I’ve honestly never been part of a forum like this before. I was just a lurker myself until less than a year ago. I was part of another flashlight forum when I first got into this a few years ago. They were not as friendly and helpful as this community and after being trolled to death by flashlight snobs just for trying to offer another perspective on a few things I walked away in disgust. But the flashlight bug bit me again and this time I found a much happier home here among thinking people willing to share ideas and not just opinions. Cheers to BLF! :beer: :beer: :beer: