Snap up that crusty DA AquaMaster for only $649.99 (free shipping!) One hose might not be completely broken. Or the one with Special Forces in the title for only $425. If it had a label they would ask for more!
EDIT: I shoulda led with, "Gee, I don't know, Charlie!"
The only difference between the Octopus in the box at the start of this thread, and a standard second stage that came with a Conshelf, Calypso, or Aquarius is that spring. OK, longer hose and decal too.
Some of you may have noticed the adjustment port in the diagram. Those came along in the 90's . Since the brass second stage box bottom was only available to the military by then, they are rarely seen. US Divers second stages available to the public at that time and presently are plastic.
Back in the 70's when we started to add a second second stage so both me and my buddy could run out of air together, many divers just grabbed a spare second stage and screwed it in. Unless the standard spring was swapped out for one designed for an octopus, that second second stage tended to free flow. I suppose if some of you have altered your DA or similar double-hose to accept an Octopus, it would be important to use the octopus spring (depending on intermediate pressure).
Interesting. I always thought it could be detuned via the locknut. At least that's what I've been doing on mine. Have I just been kidding myself?
I guess if the lever is too high, the elasticity of the diaphragm would put pressure on it, causing a freeflow. And if the lever is too low, the diaphragm will "find" it when acted upon by ambient pressure. So, having the lever too low does nothing more than lessen overall travel, diminishing maximum possible airflow. Am I thinking more clearly now?
Last Edit: Dec 17, 2019 19:05:37 GMT -8 by duckbill
Silly humans, fins are for fish. Mammals use flippers.
If you are running it off a double-hose (two-stage of course) that may be functioning well with a lower intermediate pressure, a reg with a standard spring may be working just fine. It's all about how that sucker is breathing. You know what to do, if it ain't broke.
I've got a different way of dealing with the potential free-flow problem for the octopus, and it does involve a spring. I am using a Scubapro A.I.R. I in the "Pre-Dive" position on both my Sportsways Hydro-Twin and my Sportsways Pilot regulators. In the Pre-Dive position, there is about a two-inches of water pressure spring against the main lever, and so, no free-flow.
This has been a most interesting and informative thread. I rarely use an octopus, so I don't have to deal with free flowing "safe seconds". When I dive with a bcd I have an octo attached to my inflator hose, otherwise I don't bother with them. I do pay attention to my dive buddy and my surroundings (air pressure, depth, time and location) as well as practicing the arcane exercise of free ascent.