atomic 2nds stutter

[davecampbell]

I've just completed service on a couple Atomic reg sets. Both sets have a solid IP OF 136 PSI, lockup crisply, and less than 1-2 psi of creep after sitting 30 mins pressurized. It stops there and rises no more. They were sealed with tribolube 77 without much fuss, and seem to be working perfectly.

All four 2nds were serviced identically per Atomic directions, and with the atomic tools. All have cracking set at 1.1" -1.2 " wc on a magnehelic.

1 of the 2nds have what I would call a slight stutter on inhale. it's almost like a valve with two settings... a bit of air with a very light breath, but if you increase the inhalation a bit more, it seems to open up to a second "setting".
I've tried playing around with the lever height with an inline adjusting tool, and slightly adjusting the cracking effort via the hex key, but the stutter remains. Perhaps I'm missing something?

 

[saxman242]

Sounds like the AFC doing its thing.

I notice the same on mine. At a certainly level of inhalation, the afc opens things up.

 

[davecampbell]

Sounds like the AFC doing its thing.

I notice the same on mine. At a certainly level of inhalation, the afc opens things up.

I don't think that's it. the other 3 aren't exhibiting this stutter. they're smooth all the way through.

 

[lexvil]

If you’re willing to do some parts switching with one of the other seconds try switching the poppet from one of the good ones into this one, if the problem persists switch levers. Let us know what happens.

 

[Open Ocean Diver]

I've just completed service on a couple Atomic reg sets. Both sets have a solid IP OF 136 PSI, lockup crisply, and less than 1-2 psi of creep after sitting 30 mins pressurized. It stops there and rises no more. They were sealed with tribolube 77 without much fuss, and seem to be working perfectly.

All four 2nds were serviced identically per Atomic directions, and with the atomic tools. All have cracking set at 1.1" -1.2 " wc on a magnehelic.

1 of the 2nds have what I would call a slight stutter on inhale. it's almost like a valve with two settings... a bit of air with a very light breath, but if you increase the inhalation a bit more, it seems to open up to a second "setting".
I've tried playing around with the lever height with an inline adjusting tool, and slightly adjusting the cracking effort via the hex key, but the stutter remains. Perhaps I'm missing something?

What type of 2nds are they, is the one giving you the problem a T3?

 

[davecampbell]

it's a b2 second stage

 

[davecampbell]

I think I might just be being overly cautious, with this being my first time rebuilding regs. I tried swapping a bunch of stuff around, (poppets, levers, entire air barrel) and nothing really changed.
Feeling defeated, I went out to the shop, and grabbed a set of atomics that I haven't adjusted/serviced at all. When drawing a super light breath, it also gives the same sort of two step air delivery. I'm thinking I might be over analysing... maybe.

 

[Open Ocean Diver]

I think I might just be being overly cautious, with this being my first time rebuilding regs. I tried swapping a bunch of stuff around, (poppets, levers, entire air barrel) and nothing really changed.
Feeling defeated, I went out to the shop, and grabbed a set of atomics that I haven't adjusted/serviced at all. When drawing a super light breath, it also gives the same sort of two step air delivery. I'm thinking I might be over analysing... maybe.

I have a brand new T3 first and second never in the water and it does what yours is doing. I have a older been in the water T3 first and second and it doesn’t do it.

 

[Open Ocean Diver]

I have a brand new T3 first and second never in the water and it does what yours is doing. I have a older been in the water T3 first and second and it doesn’t do it.

I just adjusted my well used T3 to .9 from 1.1 cracking effort and it now does the same thing as the brand new T3. I would say with subjective breathing it’s more of a step than a stutter. Which probably means the same thing. Try adjusting your cracking effort up a little and see what happens.

 

[Belzelbub]

Feeling defeated, I went out to the shop, and grabbed a set of atomics that I haven't adjusted/serviced at all. When drawing a super light breath, it also gives the same sort of two step air delivery. I'm thinking I might be over analysing... maybe.

Yeah, I think it's normal. I use several different Atomic B2s fairly regularly. If I breathe lightly, I can definitely feel what you are describing. As mentioned above, I do believe it's the automatic venturi opening, so it starts harder at first, then when the venturi effect kicks in, the effort drops down.