Wow! Meg design - dont know if I like this

***jradomski*** · 1st May 2007, 11:00

Quote: (Originally Posted by Steve)

Oh, and the rest of the case is one piece of plastic. It cant fail in the way Mike described.

Steve,

Teledyne cells can most definately fail in a way that they alloow gas to pas completely through the cell and still remain visually intact..

The "seal" on the side where the ckt board is sometimes fails, this alows gas to freely pass from the front of the cell and exit through the holes in the ckt board..

How much gas can pass through this.. I dont really know... On a dry scrubber with an unobstructed path probably little to none, but if the scrubber has some resistance, there would be some flow through it..

also in theory this could also change the calibration how much again I have no idea (its probably small).. The way it would change the calibration is that the side thats exposed to the atmosphere (assming a head only cal) would get gas sucked in through a venturi effect created by passing gas past the sensors on the opposite side..

henckell · 1st May 2007, 13:22

Quote: (Originally Posted by Steve)

They are hard to get apart. I used a sharp blade and it took a good while. There are 2 layers each with their own glue on the plastic wrap and the label. The end cap that I removed also has glue. I couldn't get the center section out of a cell even using a small screw driver as a pry bar. This has to come out for any gas to bypass the cell.

I recently managed to break all three cells in three different ways.

One was damaged somewhere inside and leaked through one end to the other.
The second cracked all the way around the cell body under the plastic wrap. It also leaked through.
The third split in two and lay hanging in the wires inside the sensor carriage. The threaded part was still attached in the upper part of the sensor carriage. This one obviously leaked as well.

This happened when I fell on some rocks and a +/- test of the head afterwards failed totally. Maybe the chance of something similar happening on a normal dive is quite small, but it can happen!

Drmike · 2nd May 2007, 11:18

Heres some pie to eat whilst reading the last few posts

**Steve** · 2nd May 2007, 13:24

I'm glad you agree that your original question regarding the likelihood of scrubber bypass has been put to bed Mike. Enjoy your pie.

Both of the examples given after my post wont happen during a dive and are very moot points at best.

I'm done on this one team; too many, insults, childish attachments, axes being ground and closed eyes for me. Have fun.

Drmike · 2nd May 2007, 13:35

Quote: (Originally Posted by Steve)

too many, insults, childish attachments, axes being ground and closed eyes for me. Have fun.

the insults were directed at me - by the rude insinuation that I am a liar as people were saying I couldnt have seen what I saw

The childish attachments were actually drawings I took the time to make to help users understand the safety issue I was trying to highlight on their units out of the kindness of my heart (I dont dive a meg what the hell do I care)

The only axe I have is one that promotes safety through open discussion and education

My eyes are open

I suggest that others here are guilty of all the above and not me.

And judging by the dozen green blobs I have recieved from this thread MOSTLY from Meg users Id say that most, thankfully, arent as blinkered as some letting their love for their unit overcome common sense

I mean how the hell can someone tell me I didnt witness what I saw?
They werent there. So you must only conclude Im a liar or Im insane.

My mommy taught me its an insult to call people liars - dont recall insulting anyone in this thread.

I really dont understand why your mad at me over this.

1)The fact is the Meg design can allow bypass if the cell is damaged or leaking - do you disagree with that?
2) I shared my experience with cells that became damged (fell apart)
3) You said that what I had witnessed was not possible (called me a liar)
4) Another diver described how he managed to get cells to fall apart (in a way you said was impossible)

I dont get it. You said the cells cant fall apart - yet two people have experienced it

So why are you mad at me?

Nobody said the cell has to be damaged during the dive. There is no real force on It then. It could be damaged for eg during shipment by luggage handlers or as in the previous eg when 'falling on rocks'. If the bond between the faceplate breaks as I saw the cell can still look intact on visual inspection yet can part in use. It can as in my case still function normally. At the end of the day a damaged cell can cause bypass AND cells CAN become damaged (by whatever means) as we have seen. As I mentioned fail to realise the cell is leaking during pre-dive test and it could be a problem - so just what is the problem??

Skipbreather · 2nd May 2007, 14:13

Hi Mike-

Just a note of thanks from one Meg diver who had his eyes opened to a possible failure mode I’d not previously contemplated. A likely failure? Nope, but forewarned is forearmed. “Organic fertilizer occurs”

. I’ll now be giving an extra ‘wiggle’ to each sensor during my predive setup. No rock throwing from this keyboard- just appreciation.

Best,
Ken

Drmike · 2nd May 2007, 14:19

Quote: (Originally Posted by Skipbreather)

Hi Mike-

Just a note of thanks from one Meg diver who had his eyes opened to a possible failure mode I’d not previously contemplated. A likely failure? Nope, but forewarned is forearmed. “Organic fertilizer occurs”

. I’ll now be giving an extra ‘wiggle’ to each sensor during my predive setup. No rock throwing from this keyboard- just appreciation.

Best,
Ken

Thanks Ken, Fully agree its an unlikley failure as Ive said all along.

Hey I was starting to think I should add 'critiquing Rebreather design' along with 'promoting accurate dive reporting' to the list of things I shouldnt ever talk about again due to the flak one recieves

Im happy you will give it a wiggle for me

and Im quite sure Steve will add thE wiggle test to his pre-dive checks too

***caveseeker7*** · 2nd May 2007, 14:56

People, take a deep breath and relax.

Mike's had a cell failure he reported, and found a potential problem if one like it occurs in a Meg.
I for one appreciate it. Read the failure post, seen the sensor carriage often enough,
didn't put two and two together.

Mike's gone out of his way with his drawings to illustrate what he was trying to get across,
again an effort that should be appreciated.

Small as the chance may be, it gives something else to look for. Anyone who believes that it's all nonsense feel free to ignore it, the thread, the potential problem, your choice. But stay away from insults and accusations, they are neither warranted nor acceptable.

DrJM · 2nd May 2007, 15:01

Teledyne or AI or IT Gambert cells can fall apart just with a lot of moisture exposure probably mix with sofnolime and/or spherasorb dust, I've seen it on 15.5/DDD/Boris

The 15.5 users will know what moisture+sorb do on the foam, imagine on plastic bondage ...

My own (not recommended) solution was to put some tape around the cells (on the base and body)

All my best to meg users

J

***Decodiver*** · 2nd May 2007, 15:32

Thanks for bringing this up Mike, it will form part of my Meg classes.

Cheers,

Dave.

1st May 2007, 11:00	#101 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,015	Re: Wow! Meg design - dont know if I like this Quote: (Originally Posted by Steve) Oh, and the rest of the case is one piece of plastic. It cant fail in the way Mike described. Steve, Teledyne cells can most definately fail in a way that they alloow gas to pas completely through the cell and still remain visually intact.. The "seal" on the side where the ckt board is sometimes fails, this alows gas to freely pass from the front of the cell and exit through the holes in the ckt board.. How much gas can pass through this.. I dont really know... On a dry scrubber with an unobstructed path probably little to none, but if the scrubber has some resistance, there would be some flow through it.. also in theory this could also change the calibration how much again I have no idea (its probably small).. The way it would change the calibration is that the side thats exposed to the atmosphere (assming a head only cal) would get gas sucked in through a venturi effect created by passing gas past the sensors on the opposite side.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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1st May 2007, 13:22	#102 (permalink)
henckell New Member Current Rebreather/s: Megalodon Classic Kiss Other Rebreather/s: Join Date: Aug 2005 Location: Sweden Posts: 90	Re: Wow! Meg design - dont know if I like this Quote: (Originally Posted by Steve) They are hard to get apart. I used a sharp blade and it took a good while. There are 2 layers each with their own glue on the plastic wrap and the label. The end cap that I removed also has glue. I couldn't get the center section out of a cell even using a small screw driver as a pry bar. This has to come out for any gas to bypass the cell. I recently managed to break all three cells in three different ways. One was damaged somewhere inside and leaked through one end to the other. The second cracked all the way around the cell body under the plastic wrap. It also leaked through. The third split in two and lay hanging in the wires inside the sensor carriage. The threaded part was still attached in the upper part of the sensor carriage. This one obviously leaked as well. This happened when I fell on some rocks and a +/- test of the head afterwards failed totally. Maybe the chance of something similar happening on a normal dive is quite small, but it can happen! __________________ http://www.rekodeko.se
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2nd May 2007, 13:24	#104 (permalink)
Steve Ladies bring a plate Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Classic Kiss MK 15.X Home Build Join Date: Feb 2005 Location: Perth - Australia Posts: 1,117	Re: Wow! Meg design - dont know if I like this I'm glad you agree that your original question regarding the likelihood of scrubber bypass has been put to bed Mike. Enjoy your pie. Both of the examples given after my post wont happen during a dive and are very moot points at best. I'm done on this one team; too many, insults, childish attachments, axes being ground and closed eyes for me. Have fun. __________________ WARNING: I contain occasional coarse language, extreme sexual references, nudity, and adult themes, which may offend some people - Usually churchy types. Last edited by Steve : 2nd May 2007 at 13:27.
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2nd May 2007, 13:35	#105 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: Wow! Meg design - dont know if I like this Quote: (Originally Posted by Steve) too many, insults, childish attachments, axes being ground and closed eyes for me. Have fun. the insults were directed at me - by the rude insinuation that I am a liar as people were saying I couldnt have seen what I saw The childish attachments were actually drawings I took the time to make to help users understand the safety issue I was trying to highlight on their units out of the kindness of my heart (I dont dive a meg what the hell do I care) The only axe I have is one that promotes safety through open discussion and education My eyes are open I suggest that others here are guilty of all the above and not me. And judging by the dozen green blobs I have recieved from this thread MOSTLY from Meg users Id say that most, thankfully, arent as blinkered as some letting their love for their unit overcome common sense I mean how the hell can someone tell me I didnt witness what I saw? They werent there. So you must only conclude Im a liar or Im insane. My mommy taught me its an insult to call people liars - dont recall insulting anyone in this thread. I really dont understand why your mad at me over this. 1)The fact is the Meg design can allow bypass if the cell is damaged or leaking - do you disagree with that? 2) I shared my experience with cells that became damged (fell apart) 3) You said that what I had witnessed was not possible (called me a liar) 4) Another diver described how he managed to get cells to fall apart (in a way you said was impossible) I dont get it. You said the cells cant fall apart - yet two people have experienced it So why are you mad at me? Nobody said the cell has to be damaged during the dive. There is no real force on It then. It could be damaged for eg during shipment by luggage handlers or as in the previous eg when 'falling on rocks'. If the bond between the faceplate breaks as I saw the cell can still look intact on visual inspection yet can part in use. It can as in my case still function normally. At the end of the day a damaged cell can cause bypass AND cells CAN become damaged (by whatever means) as we have seen. As I mentioned fail to realise the cell is leaking during pre-dive test and it could be a problem - so just what is the problem?? __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 2nd May 2007 at 14:14.
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2nd May 2007, 14:13	#106 (permalink)
Skipbreather Reads the fine print Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet MK 15.X Home Build Join Date: Mar 2005 Location: Chicago, Illinois, USA Posts: 557	Re: Wow! Meg design - dont know if I like this Hi Mike- Just a note of thanks from one Meg diver who had his eyes opened to a possible failure mode I’d not previously contemplated. A likely failure? Nope, but forewarned is forearmed. “Organic fertilizer occurs” . I’ll now be giving an extra ‘wiggle’ to each sensor during my predive setup. No rock throwing from this keyboard- just appreciation. Best, Ken __________________ "Entropy RULES! Enjoy the interim."
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2nd May 2007, 14:19	#107 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: Wow! Meg design - dont know if I like this Quote: (Originally Posted by Skipbreather) Hi Mike- Just a note of thanks from one Meg diver who had his eyes opened to a possible failure mode I’d not previously contemplated. A likely failure? Nope, but forewarned is forearmed. “Organic fertilizer occurs” . I’ll now be giving an extra ‘wiggle’ to each sensor during my predive setup. No rock throwing from this keyboard- just appreciation. Best, Ken Thanks Ken, Fully agree its an unlikley failure as Ive said all along. Hey I was starting to think I should add 'critiquing Rebreather design' along with 'promoting accurate dive reporting' to the list of things I shouldnt ever talk about again due to the flak one recieves Im happy you will give it a wiggle for me and Im quite sure Steve will add thE wiggle test to his pre-dive checks too __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 2nd May 2007 at 14:23.
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2nd May 2007, 14:56	#108 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,456	Re: Wow! Meg design - dont know if I like this People, take a deep breath and relax. Mike's had a cell failure he reported, and found a potential problem if one like it occurs in a Meg. I for one appreciate it. Read the failure post, seen the sensor carriage often enough, didn't put two and two together. Mike's gone out of his way with his drawings to illustrate what he was trying to get across, again an effort that should be appreciated. Small as the chance may be, it gives something else to look for. Anyone who believes that it's all nonsense feel free to ignore it, the thread, the potential problem, your choice. But stay away from insults and accusations, they are neither warranted nor acceptable. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
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2nd May 2007, 15:01	#109 (permalink)
DrJM Deep Cave Explorer Current Rebreather/s: Ouroboros Other Rebreather/s: MK 15.X Join Date: May 2005 Location: France Posts: 344	Re: Wow! Meg design - dont know if I like this Teledyne or AI or IT Gambert cells can fall apart just with a lot of moisture exposure probably mix with sofnolime and/or spherasorb dust, I've seen it on 15.5/DDD/Boris The 15.5 users will know what moisture+sorb do on the foam, imagine on plastic bondage ... My own (not recommended) solution was to put some tape around the cells (on the base and body) All my best to meg users J __________________ www.snoopyloop.com Deep Cave Exploration
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2nd May 2007, 15:32	#110 (permalink)
*Decodiver* Administrator Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,181	Re: Wow! Meg design - dont know if I like this Thanks for bringing this up Mike, it will form part of my Meg classes. Cheers, Dave. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
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