ISC Meg Modifications

[mr_v]

Ok, folks, so my BMCL setup is coming along nicely and I was thinking of using a dedicated can/reg setup for BMCL lungs so that I can make the unit hybrid. Here are the options I am considering (all will use rEvo blanked O2 DS4):

Option 1: Two MAVs

- Fathom O2 MAV with Needle Valve for the right, O2 side. Standard MAV on the left.
- Pros: I use the DIL/O2 flush procedures as I would on a standard Meg.
- Cons: Cost - I need to buy an expensive O2 MAV; two MAVs - clutter?

Option 2: One MAV block for 3 gasses, off-board; CMF in upgraded Jaksa solenoid
- rEvo MAV with output plumbed into DIL t-piece.
- Upgraded Solenoid to include CMF.
- Pros: Fairly cheap, same gas routing as rEvo - all gases go through scrubber prior to hitting the diver.
- Cons: Do I want to screw with the Meg Jaksa setup that is already working as expected?

Option 3: One Needle valve MAV block for 3 gasses, off-board (e.g., GBM, Fathom)
- MAV out is plumbed into DIL t-piece.
- Pros: Needle valve! Don't need to screw with the solenoid that is working fine. All gases go through scrubber.
- Cons: Price of the new 3 button block with a needle valve.

Your thoughts, please.

I like Option 3 the best. Seems it gets me everything I need w/o screwing with the solenoid and clutter.
The 3-button MAV idea appeals to me as I dive a rEvo and am familiar with the setup. Also, if I plumb MAV out into the exhale lung, the gas flow and flush procedures will be similar to what I am used to on a rEvo. However, there is a question of gas routing: How do I make MAV out into the exhale T-piece elegant? Dragging a long hose from the MAV into the t-piece on the opposite side seems odd to me. I could plumb MAV out into the O2 t-piece, too.

Note, the third option is essentially MEG BBKF from Silent Explorers.

 

[211ratsbud]

Why not try all of them?

I've done this myself. Including I just had a custom mav made to my spec.

I reverse the loop direction a time or two

Other small oddities.

 

[mr_v]

Why not try all of them?

I've literally done this myself. Including I just had a custom mav made to my spec.

I reverse the loop direction a time or two

Other small oddities.

Cost and time ;-)

I will probably end up trying them all though but not right away. I love Meg's customization options but hate what it does to my wallet. It has been a month since I got the Meg and I already have two setups: BMCL and TOSCL. As am lazy, I'll have two can/backplate/wing/loop/regulator setups so that I quickly take the one I want for a dive.

Must talk with the person who said "rebreathers are cheaper in the long run."

 

[Fat old english bloke]

3L tanks are 3.96" in diameter, so you can use a 4" band. It is a tight fit, but I don't like dangling tails. The clamp below has rolled edges and a smooth reverse side, so that sharp parts do not dig into the tank and leave marks.

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View attachment 870867

Maybe I’ve misunderstood something here, but I tend to use a snoopy under the jubilee/clamp, if I don’t have any wrap, and a little bit of hose for the tail to tuck into. I’ll often have a bit of hose or similar around the screw too - just keeps everything protected and reduces the risk of snagging.

For context the above is with my SM tins - my JJ tins and clamps are all still OEM.

 

[mr_v]

Maybe I’ve misunderstood something here, but I tend to use a snoopy under the jubilee/clamp, if I don’t have any wrap, and a little bit of hose for the tail to tuck into. I’ll often have a bit of hose or similar around the screw too - just keeps everything protected and reduces the risk of snagging.

For context the above is with my SM tins - my JJ tins and clamps are all still OEM.

What's a snoopy?

 

[Fat old english bloke]

What's a snoopy?

I just meant a snoopy loop - rubber strip from an old inner tube.

The photo shows the jubilee on a snoopy, plus the hose around the tail and hose around the screw. I’ve also included the carabiner in the shot as I know everyone is very fond of using these to attach kit….

Edit: obviously this is an SM
tin, not something that goes on my unit.

 

[mr_v]

I just meant a snoopy loop - rubber strip from an old inner tube.

The photo shows the jubilee on a snoopy, plus the hose around the tail and hose around the screw. I’ve also included the carabiner in the shot as I know everyone is very fond of using these to attach kit….

Edit: obviously this is an SM
tin, not something that goes on my unit.

Gotcha. I am experimenting with various barriers that prevent unnecessary wear. Helicopter tape is the best option I've found so far. It is a scotch-like tape designed to prevent debris from damaging delicate parts like helicopter blades or race car skirts. The tape is see-through, but you can see it on my cylinder.

It is a rather expensive alternative, about $30 for 2"x12' roll, but so far it seems to be the best option.