Its a bit difficult to tell what's happening inside but when the o-ring behind the lense, is presented to the torch head, its lining up directly with the head wall, where it goes when I tighten it up, is anybody's guess.. But my thinking is, thats the lense is not resting on a solid/ immovable wall/surface, which could allow it to move under pressure. To make the lense rest on an immovable wall/surface, I changed the design to:
I've removed the inner o-ring to allow the lense to sit on the head wall and have increased the diameter of the outside one to 3mm..
The front 3mm O-ring might be too big as you can see quite a bit of it from the front when tightened up.
I've a 2.5mm section O-ring which I might also try at the front.
The 2.5mm O-ring is too big to go on the body, so the 2mm one is still there.
The lense is still the stepped one, but ideally, it would be better to have one without the step.
When the smaller diameter lense sits inside the head walls.. the bezel can screw further down onto the head which might also help water tightness..maybe!
This is now in testing. Overnight bucket test ok, 4m pool test ok and this weekend 30m dive.
