need to modify

cameron · 26th December 2006, 19:34

I have run into a few guys who have " triple redundant integrated HH HUD 4th cell VR3 remote whos a whatsits" but could not explain the basic physics behind the operation of a rebreather. I have been on boats where guys are doing their MOD1 and are more worried about their integrated VR3 then they are about getting trim sorted and their bouyancy up to snuff.

Some are in this sport for the diving and some are in it for the look at me cool factor. I think most stock units out there are fairly reliable with out any modifications. An addition to the unit should be justified for the dive, not for the internet forums and the boat ride.

aknelson · 26th December 2006, 19:54

From my current observations so far of the rebreather world....some people are either are fanatics about safety or are followers.

As your last sentence mentioned....why add something to something already complex?

I respect several members whom I know from other boards as well...but some of their disaster scenarios are very far fetched. I think any rebreather is susceptible to some sort of failure no matter the precautions taken. Any backup, no matter how warm and fuzzy you think it is could be feeding you false data..given the right...err wrong circumstance, you're screwed.
................................................

IMO I see more the issue that most of the manufacturer follow a concept "going with the flow as ceap as possible"
As an engineer I am looking at the different Rebreather electronics concepts and many just lack proofen basics:
1. independent measurement system or
2. their main measurement system looks at the PO2 only but does no decompression calculation.
3. their system has not a hood display, no alarms etc.
4. no build in check list which must be followed
5. no diagnostic and logging of the controller function
6. The doctrine to run automatic systems manually ... since you need to know and control you ppo2....

I have to deal in customer service a lot with users of electronic measurement equipment and I know when such systems are not perfect functioning "screw-ups" will be happend.

Therefore I am not wondering why everyone is trying to improve their equipment. Or build it by them self. And this is a very costly way to get to what you want.

The military has the mimimal example equipment out there and the military had also a reason to build their equipment the way they did in the late 80's MK's

Why is it so hard to build complete and "dummy proof" electronics for a Rebreather system?

I am expecting from all manufacturers offering complete
systems and a uniform training concept. Why not

Andreas

scunick · 27th December 2006, 05:53

Quote: (Originally Posted by jepuskar)

Hey Andy,

I understand your point, but why all the modification then?

J

Slightly off topic, but hopefully relevant is the reason behind all the mods made to rebreathers, from my perspective anyway, is that the manufacturers are generally very effective in one area of production but terrible in others. By way of example:

My Vision is a simple and effective rebreather but:

The Harness is Pox
The Bail out regulator should be banned
The trim is not great
The "Yellow Box" is user unfriendly and limits travel
The exclusion of the promised BOV is criminal

So away we all go and do more and more modifications until we believe we have harnessed the good and nullified the bad.

In terms of a 4th cell holder I have chosen not to go down this path as Vision is my Primary and my HSE is my back-up. I dive the Vision Deco Profile (set very conservative) and if the Sh1t hits the fan I have a pure Buhlmann profile to fall back on that is more aggressive and that I have dived and trusted before.

Oh well.... off the soap box and back to reality

JMHO

Nick

**jepuskar** · 27th December 2006, 08:36

Hi Nick,

You bring up some good points as there are things about the Evolution I dont like and I havent even dove one yet.

I'm not a fan of the AIR2, I want a backplate, a BOV would be nice....is this something AP said is coming?

All these lead to modifications..although I'll give the stock version a try...but the AIR2 is just not cool at all. I'd rather sling a tank than breath off of that and I have never slung..slinged, slunged, have slung a tank before.

As I research more and more I see parts of each rebreather that I like. For example, the Optima..Dive Right gives the diver plenty of options for a BP/W...the rebreather is independent of that. Now that is nice. The Optima also has a 4th cell holder as an option...I see a nice analog PO2 monitor that could be driven by that 4th cell.

The TDI manual for the INSP/EVO suggests that you dont change anything on your rebreather for atleast the first 50 hours and seek the help of your instructor.... (So it arrives, I wait 50 hours and then change stuff...

) I agree with the thinking behind it...a new tool, new training, dive it the stock way...get use to that and than make a decision about what needs to change.

Jason

Rebreatherlab · 7th January 2007, 21:07

Hi there Silent,

The Pelagian DCCCR have had it's slow start up during last year, but is now being produced and delivered. I have tried to encourage users to write about their experience with their units on this forum, but most of them have limited web access and / or poor command of english. We will focus a bit more on the US and European markets during this year and I am sure we will soon have more reviews and discussions going.

Hopefully we will have the BOV wrapped up in mid Feb. It will be more compact than current units, but still give excellent WOB due to large inner bore and balanced 2nd stage internals. I will make sure to post pictures after testing the prototypes.

All the best,

Andy
REBREATHER LAB

Quote: (Originally Posted by silent running)

Stefan, thanks for the additional details. I couldn't remember if the HH also had a space for a 4th cell. And I'm not surprised that even a diligent diver like yourself believes that a decent SP cntroller will do a better job holding SP than a MCCR user can. Whether this makes a real difference for deco, I don't know, maybe not in normal diving.

And this is part of why I like the Pelagian for MCCR-2 sensors+ a VR/HE sensor plumbed into a comp, and OTS CLs, needle valve, modular design and-supposedly-a BOV. If only someone had actually bought one... It's a very sensible MCCR design.

IMHO, a sensor/deco comp interface is mandatory on KISS MCCR units. What if you got entangled and had to spend a lot of energy to free yourself for 20 minutes and your PO2 was all over the place? We carry knives/surgical snippers for just such an eventuality, why not an integrated O2 comp sensor? IMHO, it comes with MCCR territory.

26th December 2006, 19:34	#11 (permalink)
cameron Classic Kiss 124 Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Apr 2005 Location: Toronto, Ontario, Canada Posts: 252	Re: need to modify I have run into a few guys who have " triple redundant integrated HH HUD 4th cell VR3 remote whos a whatsits" but could not explain the basic physics behind the operation of a rebreather. I have been on boats where guys are doing their MOD1 and are more worried about their integrated VR3 then they are about getting trim sorted and their bouyancy up to snuff. Some are in this sport for the diving and some are in it for the look at me cool factor. I think most stock units out there are fairly reliable with out any modifications. An addition to the unit should be justified for the dive, not for the internet forums and the boat ride.
(Offline)

26th December 2006, 19:54	#12 (permalink)
aknelson New Member Current Rebreather/s: Ouroboros Dolphin Other Rebreather/s: Ouroboros Dolphin Join Date: Dec 2005 Location: Minnesota Posts: 78	Re: need to modify From my current observations so far of the rebreather world....some people are either are fanatics about safety or are followers. As your last sentence mentioned....why add something to something already complex? I respect several members whom I know from other boards as well...but some of their disaster scenarios are very far fetched. I think any rebreather is susceptible to some sort of failure no matter the precautions taken. Any backup, no matter how warm and fuzzy you think it is could be feeding you false data..given the right...err wrong circumstance, you're screwed. ................................................ IMO I see more the issue that most of the manufacturer follow a concept "going with the flow as ceap as possible" As an engineer I am looking at the different Rebreather electronics concepts and many just lack proofen basics: 1. independent measurement system or 2. their main measurement system looks at the PO2 only but does no decompression calculation. 3. their system has not a hood display, no alarms etc. 4. no build in check list which must be followed 5. no diagnostic and logging of the controller function 6. The doctrine to run automatic systems manually ... since you need to know and control you ppo2.... I have to deal in customer service a lot with users of electronic measurement equipment and I know when such systems are not perfect functioning "screw-ups" will be happend. Therefore I am not wondering why everyone is trying to improve their equipment. Or build it by them self. And this is a very costly way to get to what you want. The military has the mimimal example equipment out there and the military had also a reason to build their equipment the way they did in the late 80's MK's Why is it so hard to build complete and "dummy proof" electronics for a Rebreather system? I am expecting from all manufacturers offering complete systems and a uniform training concept. Why not Andreas
(Offline)

27th December 2006, 05:53	#13 (permalink)
scunick Nick Cunningham-Moorat Current Rebreather/s: Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Other CCR Join Date: Jun 2005 Location: South Africa - Cape Town Posts: 95	Re: need to modify Quote: (Originally Posted by jepuskar) Hey Andy, I understand your point, but why all the modification then? J Slightly off topic, but hopefully relevant is the reason behind all the mods made to rebreathers, from my perspective anyway, is that the manufacturers are generally very effective in one area of production but terrible in others. By way of example: My Vision is a simple and effective rebreather but: The Harness is Pox The Bail out regulator should be banned The trim is not great The "Yellow Box" is user unfriendly and limits travel The exclusion of the promised BOV is criminal So away we all go and do more and more modifications until we believe we have harnessed the good and nullified the bad. In terms of a 4th cell holder I have chosen not to go down this path as Vision is my Primary and my HSE is my back-up. I dive the Vision Deco Profile (set very conservative) and if the Sh1t hits the fan I have a pure Buhlmann profile to fall back on that is more aggressive and that I have dived and trusted before. Oh well.... off the soap box and back to reality JMHO Nick
(Offline)

27th December 2006, 08:36	#14 (permalink)
jepuskar NA Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Aug 2005 Location: Chicago, IL Posts: 397	Re: need to modify Hi Nick, You bring up some good points as there are things about the Evolution I dont like and I havent even dove one yet. I'm not a fan of the AIR2, I want a backplate, a BOV would be nice....is this something AP said is coming? All these lead to modifications..although I'll give the stock version a try...but the AIR2 is just not cool at all. I'd rather sling a tank than breath off of that and I have never slung..slinged, slunged, have slung a tank before. As I research more and more I see parts of each rebreather that I like. For example, the Optima..Dive Right gives the diver plenty of options for a BP/W...the rebreather is independent of that. Now that is nice. The Optima also has a 4th cell holder as an option...I see a nice analog PO2 monitor that could be driven by that 4th cell. The TDI manual for the INSP/EVO suggests that you dont change anything on your rebreather for atleast the first 50 hours and seek the help of your instructor.... (So it arrives, I wait 50 hours and then change stuff... ) I agree with the thinking behind it...a new tool, new training, dive it the stock way...get use to that and than make a decision about what needs to change. Jason
(Offline)

7th January 2007, 21:07	#15 (permalink)
Rebreatherlab RebreatherWorld Sponsor Current Rebreather/s: Pelagian Other Rebreather/s: Not Bought Yet Classic Kiss Pelagian Join Date: Sep 2005 Location: Thailand Posts: 202	Re: need to modify Hi there Silent, The Pelagian DCCCR have had it's slow start up during last year, but is now being produced and delivered. I have tried to encourage users to write about their experience with their units on this forum, but most of them have limited web access and / or poor command of english. We will focus a bit more on the US and European markets during this year and I am sure we will soon have more reviews and discussions going. Hopefully we will have the BOV wrapped up in mid Feb. It will be more compact than current units, but still give excellent WOB due to large inner bore and balanced 2nd stage internals. I will make sure to post pictures after testing the prototypes. All the best, Andy REBREATHER LAB Quote: (Originally Posted by silent running) Stefan, thanks for the additional details. I couldn't remember if the HH also had a space for a 4th cell. And I'm not surprised that even a diligent diver like yourself believes that a decent SP cntroller will do a better job holding SP than a MCCR user can. Whether this makes a real difference for deco, I don't know, maybe not in normal diving. And this is part of why I like the Pelagian for MCCR-2 sensors+ a VR/HE sensor plumbed into a comp, and OTS CLs, needle valve, modular design and-supposedly-a BOV. If only someone had actually bought one... It's a very sensible MCCR design. IMHO, a sensor/deco comp interface is mandatory on KISS MCCR units. What if you got entangled and had to spend a lot of energy to free yourself for 20 minutes and your PO2 was all over the place? We carry knives/surgical snippers for just such an eventuality, why not an integrated O2 comp sensor? IMHO, it comes with MCCR territory.
(Offline)

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