+ Reply to Thread
Page 3 of 6 FirstFirst 1 2 3 4 5 6 LastLast
Results 21 to 30 of 51

Thread: AHHHH! I can't decide what rebreather I want!

  1. #21
    Urrrgh! Ukon is an unknown quantity at this point Ukon's Avatar
    Join Date
    Dec 2006
    Location
    Northeast
    Posts
    109
    rEvo II

    KISS Classic

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Mark Chase  View Original Post
    Why?

    I have dived MCCR down to 95m and didnt think it was any diferent to diving it to 30m in terms of 02 add?

    SO i am curious to know why or do you mean past the max depth for CMF 02?
    Yes, I've had mine down to around 350' a couple of times. I found my O2 addition stopped functioning abruptly about 290'.

    This was cured with an additional O2 bottle, however this resulted in some scary spikes!

    Even though we don't do that many of these dives, it just seems it would be easier, and a bit safer moving on to H/ECCR.

  2. #22
    So many CCR So little etc Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase's Avatar
    Join Date
    Jan 2005
    Location
    Kent
    Posts
    5,205
    JJ Hybrid

    Inspo, Hammer Head, KISS rEvo

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Ukon  View Original Post
    Yes, I've had mine down to around 350' a couple of times. I found my O2 addition stopped functioning abruptly about 290'.

    This was cured with an additional O2 bottle, however this resulted in some scary spikes!

    Even though we don't do that many of these dives, it just seems it would be easier, and a bit safer moving on to H/ECCR.

    Yes i went through the same stage

    Had some 125m dives planned and decided my KISS wasent up to it (craped out at 110m ) so switched to a hibrid rEvo and ran past 100 on ECCR

    Problem was it was a bit like "OK just one more drink"

    Before I knew it I was running ECCR for everything

    Got really lazy and complacent so now heading back to MCCR before i hurt my self

    ATB

  3. #23
    RBW Member P-A is an unknown quantity at this point P-A's Avatar
    Join Date
    Jun 2012
    Location
    Sweden
    Posts
    64
    Pelagian DCCCR

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Ukon  View Original Post
    Yes, I've had mine down to around 350' a couple of times. I found my O2 addition stopped functioning abruptly about 290'.

    This was cured with an additional O2 bottle, however this resulted in some scary spikes!

    Even though we don't do that many of these dives, it just seems it would be easier, and a bit safer moving on to H/ECCR.
    Did you have a malfunction or did you actually dive deeper than the sonic flow of the mccr was constructed for.

    If you dive with a balanced first stage and needle valve on you oxygen addition this will never be a problem.

  4. #24
    Urrrgh! Ukon is an unknown quantity at this point Ukon's Avatar
    Join Date
    Dec 2006
    Location
    Northeast
    Posts
    109
    rEvo II

    KISS Classic

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Mark Chase  View Original Post
    Yes i went through the same stage

    Had some 125m dives planned and decided my KISS wasent up to it (craped out at 110m ) so switched to a hibrid rEvo and ran past 100 on ECCR

    Problem was it was a bit like "OK just one more drink"

    Before I knew it I was running ECCR for everything

    Got really lazy and complacent so now heading back to MCCR before i hurt my self

    ATB
    I'd be interested in seeing how you've altered your JJ to hybrid Mark.

  5. #25
    Urrrgh! Ukon is an unknown quantity at this point Ukon's Avatar
    Join Date
    Dec 2006
    Location
    Northeast
    Posts
    109
    rEvo II

    KISS Classic

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by P-A  View Original Post
    Did you have a malfunction or did you actually dive deeper than the sonic flow of the mccr was constructed for.

    If you dive with a balanced first stage and needle valve on you oxygen addition this will never be a problem.
    Yes, that is an interesting option. I've not seen it used by anyone around here. I am curious as to why?

  6. #26
    So many CCR So little etc Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase has a reputation beyond repute Mark Chase's Avatar
    Join Date
    Jan 2005
    Location
    Kent
    Posts
    5,205
    JJ Hybrid

    Inspo, Hammer Head, KISS rEvo

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Ukon  View Original Post
    I'd be interested in seeing how you've altered your JJ to hybrid Mark.

    Its not a true hybrid but all I did was replace the 02 add button with a needle valve and run the unit manualy on low set point using a balanced first stage to maintain IP presure for the solonoid

    ATB

  7. #27
    CCR Cave Explorer jcr is an unknown quantity at this point jcr's Avatar
    Join Date
    Oct 2010
    Location
    Gainesville, FL
    Posts
    15
    Fathom CCR

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by Ukon  View Original Post
    Yes, I've had mine down to around 350' a couple of times. I found my O2 addition stopped functioning abruptly about 290'.

    This was cured with an additional O2 bottle, however this resulted in some scary spikes!

    Even though we don't do that many of these dives, it just seems it would be easier, and a bit safer moving on to H/ECCR.
    eCCR is not your only option as there are mCCR units that can handle the depth. The Pelagian is one but does require close attention during depth changes.

    Another soon to be available option is the FATHOM mCCR, which uses a needle valve with an uncompensated (blocked) first stage and stronger spring. This configuration gives you the ease of use of a fixed orifice with greater flexibility since you're not tied to a certain IP pressure to deliver the correct flow.

    I've been diving and testing this configuration for some time now and have found it incredibly stable and easy to use. I have my IP set at 200 psi, which give a practical depth limit of 400 fsw. If needed, I can adjust my IP up to 290 psi, which would give me a practical depth limit of 600 fsw. My hoses have a 400 psi working pressure so no problems there. I've had the unit to 353 ffw on a deep exploration dive without issue.

    Charlie Roberson
    FATHOM Dive Systems, LLC
    jcr@fathomdive.com

  8. #28
    CCR Cave Explorer jcr is an unknown quantity at this point jcr's Avatar
    Join Date
    Oct 2010
    Location
    Gainesville, FL
    Posts
    15
    Fathom CCR

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by P-A  View Original Post
    Did you have a malfunction or did you actually dive deeper than the sonic flow of the mccr was constructed for.
    Both the CMF and manual add stop flowing oxygen when the ambient pressure meets the fixed IP pressure of an uncompensated (blocked) first stage.

    The two solutions are to increase the IP pressure or use a compensated first stage.

  9. #29
    Steve Sprague 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster is a glorious beacon of light 4ster's Avatar
    Join Date
    Mar 2006
    Location
    Arlington, WA
    Posts
    650
    rEvo

    Dolphin

    Re: AHHHH! I can't decide what rebreather I want!

    I have only done a few dives in the 100 meter range on my manual rEvo, and I used a small off board bottle of O2 with a compensating regulator. I wouldn't do it again.

    I've not done this, so take it with a grain of salt, but if I were to do a 100M+ dive again:

    When diving a manual or hybrid RB with a fixed IP another option is to use "rich diluent" via your off board plumbing at depths over the IP limit. This avoids adding pure O2 and problems of spiking, or buy a little more response time with a stuck add button malfunction. This could be a small bottle with rich bottom mix appropriate for your planned max depth or one of your bailout tanks with a higher than normal percentage (for bailout) of He.

    This has been discussed here on RBW before, I'm just reminding that the strategy exists.
    Last edited by 4ster; 16th June 2016 at 19:07.

  10. #30
    Urrrgh! Ukon is an unknown quantity at this point Ukon's Avatar
    Join Date
    Dec 2006
    Location
    Northeast
    Posts
    109
    rEvo II

    KISS Classic

    Re: AHHHH! I can't decide what rebreather I want!

    Quote Originally Posted by 4ster  View Original Post
    I have only done a few dives in the 100 meter range on my manual rEvo, and I used a small off board bottle of O2 with a compensating regulator. I wouldn't do it again.

    I've not done this, so take it with a grain of salt, but if I were to do a 100M+ dive again:

    When diving a manual or hybrid RB with a fixed IP another option is to use "rich diluent" via your off board plumbing at depths over the IP limit. This avoids adding pure O2 and problems of spiking, or buy a little more response time with a stuck add button malfunction. This could be a small bottle with rich bottom mix appropriate for your planned max depth or one of your bailout tanks with a higher than normal percentage (for bailout) of He.

    This has been discussed here on RBW before, I'm just reminding that the strategy exists.
    Yes, I've done this also. I ran deep bailout in semi, SCR mode.
    I've also considered running a small bottle of 80/20 heliox to use in place of O2 to try to keep the spikes down.

+ Reply to Thread
Page 3 of 6 FirstFirst 1 2 3 4 5 6 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts