So what are people's thoughts on Atomic's Automatic Flow Control? Good, bad or indifferent?

[CapnBloodbeard]

G'day brains trust!
So, wife and I are both in the market for a new reg, narrowed it down to one of the Atomic Aquatics ones (B2 or Z2/3......I'm thinking the difficult/expensive-to-replace-hose due to the 'comfort swivel' is a bit of a concern), Aqualung Leg3nd (probably the elite.....don't think I like the 'one-knob' idea of the MBS.....it seems to me that it's taking adjustment options away from the diver.....), and Apeks XTX200.

Plenty of threads on here about those so I'll do some more reading - but specifically, what do people think about the Automatic Flow Control (AFC) of the Atomic regs? Fantastic? Gimmick? Detrimental?

From what I gather, it supposedly removes the need to make breathing knob adjustments as you go deeper (frustratingly, neither my wife or I were taught anything about those adjustments or the dive/predive switch in our PADI courses). So just wondering how I should factor that into my considerations...so is it good, is it bad in taking away options, is it a minor convenience that doesn't really matter?

From what I gather, the AFC is about the effort required to 'break the seal' - to initiate a breath, and you still have the adjustment knob for how much force it takes to keep breathing, is that more or less correct?

 

[Geo7]

I went through the same thought process when I first got into Atomic regs. Personally, I'd prefer as much adjustability as possible, because then I can park a reg as an octo or stage reg and make it breathe really hard. That's what I was used to, but I found this not being necessary with the Atomics.

You are correct, there are two different aspects: What we are talking about is 1) the round knob adjusting the spring to affect the cracking pressure, and 2) changing the position of a vane that affects the venturi effect.

Venturi effect, or venturi assist, greatly affects how a reg breathes. In most Scubapro regs that vane rotates and can direct the air into the divers mouth, while pulling more air with it. Apeks has that vane fix, and blocks the airpath using a rotating cylinder. Venturi at max setting increases the vaccum, thus depressing the valve lever for you (assisting). For this to make sense one has to look how a jet of air pulls more air with it (think airbrush). If you turn the small venturi knob on an Apeks or Scubapro to min, you block the airpath and make it breathe harder. If you put it on max, the air really flows and the reg feels like it has no breathing resistance at all. Manufacturers go to great lengths today to design the lever and the entire housing so that the venturi does not cross over into positive flow (perhaps @rsingler can post some of his excellent charts for us). That makes regs breathe natural and smooth.

The Atomic venturi vane does not rotate, but instead slides as it is pulled by an air bubble created with a membrane. It shifts either a hole or a flat plane into the airstream and increases or decreases turbulence or venturi respectively. The bubble compresses as you get to 20 feet, where it approaches its max setting. So at the surface it won't freeflow. You have to use the cracking pressure to put the octo on minus.

Normally I am against automation, but found that the Atomic AFD is such a simple mechanism that it cannot dramatically fail. I find that the Atomic stays in an breathing resistance range with little adjustment. I get no freeflows with the octo set halfway to minus, and they really do breathe great. The engineers refining this had lots of experience, and it shows. I expected to get into situations where not having the venturi adjust would be a problem, but the thing just works like advertised. I was also skeptical about the floating seat, but it just works for me without any drawbacks. That's because they found very simple engineering solutions for what they wanted to achieve. They can go years without maintanence.

Legends are fine regs, but I feel they have overdone it with the automation of the MBS and ACD, at least for my preferences. Someone else who knows them better can explain the pros and cons.

Usually I buy the 15$ jam nut from Atomic, remove the swivel and put a normal Atomic hose on my regs and sell the swivel hose. All balanced regs need a jam nut. There is no difference to other regs really. Atomic regs with a swivel just have that nut integrated into the swivel, and you just have to buy a separate one for 15$ in order to put normal hoses on it, that's all.

Finally, I am diving more expensive Atomic models, and ocassionally kick myself for not having gotten the Z2...

 

[Manatee Diver]

The only time I really work those adjustment knobs is if something is free flowing, or the reg just doesn't feel right. Otherwise I set them to the least resistance possible, and just leave them there.

 

[lexvil]

Always worked seamlessly for me, for manual type the Apeks type (everyone but SP uses the same type with a shield that rotates to block flow right on the barrel, much more effective than the SP type. I don’t recall an Atomic ever freeflowing so it must work well for that and I never noticed it while diving.

 

[BoltSnap]

one of the Atomic Aquatics ones (B2 or Z2/3

Get either the B2 or the Z2 (sealed versions) and skip the Z3. The Z3 is the Z2 but with an overpriced permanently attached LP hose swivel.

Automatic Flow Control (AFC) of the Atomic regs? Fantastic? Gimmick? Detrimental?

Fantastic, best design for Venturi adjustment I have used. Makes the Venturi intervention smooth and natural. It is in full effect upon reaching 20meters and deeper.

From what I gather, the AFC is about the effort required to 'break the seal' - to initiate a breath, and you still have the adjustment knob for how much force it takes to keep breathing, is that more or less correct?

The AFC is for automatic depth based Venturi adjustment NOT for adjusting cracking pressure. The rotating knob on the second stage is used for adjusting the cracking pressure, the initial effort to open the valve when initiating inhalation.

The adjustment knob is turned all the way out when starting the dive, with second stage in mouth, and turned in when in water and second stage is out of the mouth. The AFC does its beautiful magical work automatically.

 

[jonhall]

I've only owned one reg (Aqua Lung Mikron) which I've used for 10 years, so I am looking at this thread as a possible shopper for a new reg for the type of diving I do, warm water rec dives. Sometime early on I played around with my reg's adjustment knob -the VAK - once or twice to see what the effects were. Currently my adjustment knob is set more towards the easier breathing direction (counter-clockwise for the Aqua Lung) and that is where it has been, so in that regard, like @Manatee Diver I don't even think about it when I dive. No adjusting while diving and no issues when the reg is in or out of the water.

The Atomic has AFC, which under normal circumstances should stay in one position, but still has a rapid adjustment knob - RAK - for certain situations. As @BurhanMuntasser wrote, "The adjustment knob is turned all the way out when starting the dive, with second stage in mouth, and turned in when in water and second stage is out of the mouth." Although I don't believe it to be the case, my question would be, does this mean I need to make a manual adjustment every time I'm in or out of the water to prevent a free flow?

The AFC is definitely a selling point - a Fantastic Gimmick - don't see anything detrimental about it but is it really any better than others with only the adjustment knob? I can't say I have seen many (or any) divers using this adjustment. Hope you get a lot of replies from actual divers who have used these different regs. They are the testers and reviewers who regular divers like me, who can't go out and try everything, depend on.

*By the way, thanks for the thread - as I went to check my reg to get an idea of where my VAK was set, I found the knob was missing. One year and 2 weeks ago on my last dive it was there!

 

[Geo7]

does this mean I need to make a manual adjustment every time I'm in or out of the water to prevent a free flow?

I think most of us don't interfere with the controls of Atomic regs for normal diving at all. And my primary is set more sensitive than specified by the manufacturer. The octo or a stage reg I'd leave on min.

 

[StefinSB]

You are overthinking it. The AFC simply saves you from forgetting to manually switching your Venturi adjuster from pre-dive to dive and vice versa.

 

[BoltSnap]

I've only owned one reg (Aqua Lung Mikron) which I've used for 10 years, so I am looking at this thread as a possible shopper for a new reg for the type of diving I do, warm water rec dives. Sometime early on I played around with my reg's adjustment knob -the VAK - once or twice to see what the effects were. Currently my adjustment knob is set more towards the easier breathing direction (counter-clockwise for the Aqua Lung) and that is where it has been, so in that regard, like @Manatee Diver I don't even think about it when I dive. No adjusting while diving and no issues when the reg is in or out of the water.

The Atomic has AFC, which under normal circumstances should stay in one position, but still has a rapid adjustment knob - RAK - for certain situations. As @BurhanMuntasser wrote, "The adjustment knob is turned all the way out when starting the dive, with second stage in mouth, and turned in when in water and second stage is out of the mouth." Although I don't believe it to be the case, my question would be, does this mean I need to make a manual adjustment every time I'm in or out of the water to prevent a free flow?

The AFC is definitely a selling point - a Fantastic Gimmick - don't see anything detrimental about it but is it really any better than others with only the adjustment knob? I can't say I have seen many (or any) divers using this adjustment. Hope you get a lot of replies from actual divers who have used these different regs. They are the testers and reviewers who regular divers like me, who can't go out and try everything, depend on.

*By the way, thanks for the thread - as I went to check my reg to get an idea of where my VAK was set, I found the knob was missing. One year and 2 weeks ago on my last dive it was there!

Some people here who don't know Atomic regulators are confusing what the AFC does and what the cracking pressure adjustment knob does. The AFC has to do with venturi adjustment based on depth (more venturi as you go deeper with full venturi starting at around 20meters) while the knob has to do with "cracking pressure" adjustment. Venturi and cracking pressure are two different things. The Atomic AFC feature isn't a gimmick at all, far from it. AFC is one of the best features on the Atomic second stage. The AFC works automatically and "naturally" and is very subtle that people don't know it is there and how it works but they get the benefit of the feature without having to remember to turn venturi on before going down underwater or off when on the surface. It makes the Atomic second stage one of the best performing with natural breathing second stages out there (and probably the most reliable by virtue of its design).