Difference in sealing designs

[Codiak]

So I'm tossing around designs and am wonder what the differences are between inny and outty type the seals, and if one really is better than the other or if it's just personal preference.

Inny would be defined as the battery butt plug of a mag where we screw it in. (sick-o's)
Outty would be the lens cap where we screw it on.

[gcbryan]

I don't know so I'm sure you'll get better answers than that but I would think the internal threaded design would be better. At least bumping it into something wouldn't be as likely to allow it to come unscrewed.

The diameter for an internal design should be less and I would think that would be a plus as well.

[DIWdiver]

So I'm tossing around designs and am wonder what the differences are between inny and outty type the seals, and if one really is better than the other or if it's just personal preference.

Inny would be defined as the battery butt plug of a mag where we screw it in. (sick-o's)
Outty would be the lens cap where we screw it on.

I think it really depends on the application. The guys at MAG are serious professionals; at one end they used an innie, and at the other they used an outie. That pretty much tells you the story.

Except that it doesn't. If you screw the head into the ring, and the plug into the butt, the sexes are the same. The fact that you THINK you're screwing the ring onto the head doesn't change anything. In both cases the o-ring is behind the male threads.

The real story is away from the joint. The head has to be the male portion, so that the front edge of the head can press the lens against the front ring, compressing the o-ring and making a seal. The other difference is that the side with the female threads can have a larger bore, where a bore through the male threads must be smaller. The bore in the tube needs to be larger than does the one in the endcap, so it's got the female thread. Similarly, because it has the female thread, the opening of the front ring can be larger than the ID of the head, which is as it should be.

[Codiak]

GC and DIW thanks for replying.

I think DIW hit on one critical item I hadn't put words to

In both cases the o-ring is behind the male threads.

The real story is away from the joint. The head has to be the male portion, so that the front edge of the head can press the lens against the front ring, compressing the o-ring and making a seal.

There are implementations where the head is female and I've even considered this lately as it would allow for narrower overall diameters.

Still... options options options

[lucca brassi]

IMO :
Only important thing is to twist O ring by rotation - less as it is possible in groove.

For frequent rotation must be O rings designed in other way (pneumatic cylinders ) or must be other part so designed that O ring could rotateand seal ( compress conic shape )

Best sealing is front compression of O ring!