S360 Octopus - Tuning - appropriate cracking effort for an Octopus

[aoumi]

Hi,

Just wondering if anyone can shed some light on this. Usually for my primary Scubapro 2nd stage, I tune the cracking effort to 1.1-1.2 inches of water.

But, I have no idea what the appropriate level is for an Octopus. I have an S360 Octo, I imagine that it needs to be set a bit more than the normal 1.1-1.2 inches of water. Is 1.4 an appropriate value?

Bear in mind this Octo has no inhalation resitance knob, just a venturi adjustment.

Any opinions much appreicated, thanks.

 

[rsingler]

I'll typically set mine for 1.4". Scubapro specs 1.4-1.5" as I recall.
There is no right answer. Whatever gives you an acceptably breathing regulator when the person you are donating to may be panicked, while not resulting in a freeflow if it gets banged around in the surf.

Great reg, though! Improved poppet design and great work of breathing. I wish it had caught on more out here in California. One of the lowest friction levers out there. Trouble is, the lever resembles an old design that had had problems, so some folks shy away after looking at the inside.

 

[aoumi]

Good advice rsingler, thank you! I'll set it in that 1.4-1.5 range, I quite like that reg too. I also have its brother the S560 as a primary, but I find it more difficult to tune with all the micro- adjustment in the inhalation adjustment knob.

 

[rsingler]

Good advice rsingler, thank you! I'll set it in that 1.4-1.5 range, I quite like that reg too. I also have its brother the S560 as a primary, but I find it more difficult to tune with all the micro- adjustment in the inhalation adjustment knob.

Unless I'm misremembering the schematics, both have micro adjust screws (560 inside the knob, 360 inside the case), and should be tuned the same way:
With the reg on first stage IP, and all adjustment screws fully out, adjust the orifice until the reg seals at IP.
Add 1/24th to 1/12th of a turn (2 1/2 to 5 min on the clock) on the orifice.
Suck on the magnehelic, and set the micro-adjuster until your cracking effort is 1.1-1.5" as desired.
Done.
S560 adjustment knob only increases cracking effort from your setpoint.
A few manufacturers specify a tiny freeflow with the adjustment knob fully out, so you can set cracking effort whatever you want, but Scubapro is not like that.

 

[aoumi]

Thank you for that info on the setting/adjustment, i'll give that a try, appreciated. These 2nd stages are great for travel, not so big and very light, so looking forward to some more dives on them.