Atomic B1:proper 'position' for external adjustment knob to setting 'cracking effort'

[scubafanatic]

Hi,

I've got a B1, which has 1 external 2nd-stage knob for adjusting 2nd-stage cracking effort, I prefer the 2nd-stage cracking effort to be VERY low when the knob is dialed all the way 'out'.....when I'm at the LDS for an annual, is this something specific I need to specify before the service?

I guess I'm wondering how closely related cracking-effort is to the particular position the 2nd-stage knob happens to be in ?

Thanks,

Karl

 

[Charlie99]

You need to tell the LDS that you want the reg to have lower than factory recommended cracking pressure. When getting my B1 serviced I ask for "near freeflow" or near zero cracking at the most sensitive setting.

The downside is that after 100 dives, normal seat wear will make so that the cracking pressure knob will have to be adjusted inward a ways to keep it from freeflowing, even while in my mouth.

If I don't say anything to my LDS, they set the cracking pressure up to whatever the spec is -- something like 1/2 inch H2O cracking pressure with knob in the lowest cracking pressure setting. This means that it is somewhere around 1inch in the in position.

I prefer the very low cracking pressure and ask that it be set to near free flow at the most sensitive. This ends up around 1/2 inch dialed in as the adjustment range is about 1/2" total IIRC. (.1" to 0.6" is my preference, 0.5" to 1.0" is the typical setting by the LDS)

With this sort of setting, it will always freeflow if out of your mouth and reg mouthpieced pointed upwards. So a reg setup this sensitive is not suitable as an octopus or as a primary stage that one clips off while breathing a deco tank. This is probably why the manufacturer recommendation and normal LDS practice is to have a bit higher cracking pressure.

 

[scubafanatic]

You need to tell the LDS that you want the reg to have lower than factory recommended cracking pressure. When getting my B1 serviced I ask for "near freeflow" or near zero cracking at the most sensitive setting.

The downside is that after 100 dives, normal seat wear will make so that the cracking pressure knob will have to be adjusted inward a ways to keep it from freeflowing, even while in my mouth.

If I don't say anything to my LDS, they set the cracking pressure up to whatever the spec is -- something like 1/2 inch H2O cracking pressure with knob in the lowest cracking pressure setting. This means that it is somewhere around 1inch in the in position.

I prefer the very low cracking pressure and ask that it be set to near free flow at the most sensitive. This ends up around 1/2 inch dialed in as the adjustment range is about 1/2" total IIRC. (.1" to 0.6" is my preference, 0.5" to 1.0" is the typical setting by the LDS)

With this sort of setting, it will always freeflow if out of your mouth and reg mouthpieced pointed upwards. So a reg setup this sensitive is not suitable as an octopus or as a primary stage that one clips off while breathing a deco tank. This is probably why the manufacturer recommendation and normal LDS practice is to have a bit higher cracking pressure.

Hi Charlie99,

Thank you for your response, I'll now have a better idea of what to ask for at the next service. I've had issues at a couple of Atomic dealers getting mine set up properly, this will help me explain things to them. The reg in question is only for the primary 1st-stage of a recreational reg set, so I'm not too worried about it becoming 'too sensitive'......a while back it was a sensational reg, then I had it serviced and it performed significantly worse than before the service! Among other things it came back from service with an IP of about 110-115......got that fixed with 'spacers' in the 1st-stage so now that's back at about 135....... but the last time I dove it in the Bahamas I felt I still had to 'pull for the air' relative to the way it once was ( ie Bonaire summer '05).....it's my belief that I need to have the dealer make sure the adjustment knob is in the 'proper' position prior to setting the cracking pressure, hopefully that will fully restore it.

Karl