• For an innner sleeve to hold the wavien collar, all you need is a weak spring behind it extending the sleeve and collar into position, and a stop so it stops extending at the right point. In flood mode the retracted bezel or lens retaining ring would then push the collar behind the LED.
  • For the bezel: I have a zoomie that does not have any stop to prevent the bezel coming off. In practice it does not work well. When you want spot mode, you want to be able to quickly pull the bezel forward and have it stop at max throw. You don’t want to have to think about having to manually focus it in each time… or pull too hard and have your light pull apart.

The most common way to do this is the following: The front of the bezel is a lens retaining ring. Unscrew it and the lens comes out the front. With the lens removed from the bezel, you can then reach into the light and unscrew the pill or retaining ring using snap-ring pliers. The pill or retaining ring has a lip that sticks out and prevens the bezel from extending too far.

If you’re serious about possibly producing this design, I recommend purchasing a cheap zoomie flashlight and taking it apart. You’ll instantly see what I’m talking about and why it’s helpful.

Other issues to consider:

  • Will the light be airtight? - it looks like from the drawing you have o-rings sealing all ports of entry except maybe the USB port. Push-pull zoomies face a perhaps unexpecxted complication when made airtight:

Retracting or extending the bezel changes the internal volume of the light. If you put in the battery and seal the light, air pressure inside the light will match that outside the light. But if you then move the bezel out of position from what it was when the light was sealed, the internal air pressure inside the light will change. Air pressure inside the light will then try to equalize with air pressure outside the light. The result:

  • After you seal up the light by putting in the battery, equalizing air pressure will cause the sliding bezel to retract or extend into whatever position it was in when the light was sealed.
  • If you put in the battery or closed the USB port cover when the bezel was extended and then retract the bezel, air pressure will either eject the USB port cover or cause the bezel to automatically extend.

This is why most budget zoom flashlights are intentionally not airtight. They might contain o-ring slots for all openings, but usually one o-ring is missing so air pressure inside and outside can equalize for smooth zoom action.

To prevent this problem and still have an air-tight light you need a VERY stiff zoom mechanism. In practice, I haven’t seen any push-pull zoomies that are truly watertight. The only zoomies that are tend to have a bezel that screws and unscrews and are stiff enough to require two hands to cycle.

You would have an added complication of a USB port. A standard rubber USB port cover probably wouldn’t be sufficient unless the jack itself is watertight and sealed off from the rest of the light even when the cover is off. Or you could use a sliding cylindrical cover with o-rings to protect the port instead of the standard rubber cover. Or you could just leave an opening somewhere in the light so air pressure can equalize.