It lives! The Hasslehuff.

[Woz]

Originally Posted by Digger

Woz, I don't know how to break this to you, but I need that needle and ball valve back.

Hahahaahahahaha no chance. It's working the breather.

[Digger]

If you're relying on those to work the breather then you might want to check the life insurance policy. The valves may have a stay of execution, as I seem to have found a nice solution to my previous problem of trying to run two rebreathers at once in the same unit. Photos to follow. If I could work out how to upload photos. I know, it's simple. But so am I.

Digs.

[Woz]

Well I don't rely on it. Just dribbles O2 in so I don't have to press the yellow "keep me alive for a bit longer" button so often.

I know I know I should really have a DS4 with fixed IP and an orifice from Norgren like a rEvo if I'm going to stick to sports diving depths but where's the fun in that? Mind you I saw a way of fixing the IP of a mk2 that was so laughably simple I'm going to give it a go.

I'm fairly sure the life insurance policy doesn't mention home-built rebreathers in it. Then again it might be considered a form of suicide...

[Duncan Price]

Originally Posted by ardhill

Wasn't Dr Dunc playing with a backmounted RB himself? Was this a modified D5 or a new build do you know?

Yes - was diving mine at Vobster recently:









I wear my cylinders sidemounted. The whole unit can be side slung in a few minutes swopping the standard Ray mouthpiece for a sidemount one. I'm building up another to dedicate as a backmount unit and going to wear them side by side on my back like twin 7's.

[ardhill]

Very nice, you still look like a cave diver with the cylinders side mounted. Well I guess then no body thinks twice to see you diving an 'unbranded' breather, 'cause everone knows you UK cave divers are a bit well, you know, mental...

Oh how I laughed when I heard Martyn Farr saying that he didn't like going deeper than 70m 'cause it was too dangerous Ha ha ha haaaa.

Anyway, I see a D5 range coming on :
- Pure side mount for the UK cavers
- Side mount conversion
- Back mounted for the 'normal' people.
Quite an industry in the making.

[Woz]

Don't forget a D5 for a deep sidemount bailout rebreather for the 100m + ocean divers. Saves carrying all those pesky bailout cylinders.

[Duncan Price]

Originally Posted by ardhill

Very nice, you still look like a cave diver with the cylinders side mounted. Well I guess then no body thinks twice to see you diving an 'unbranded' breather, 'cause everone knows you UK cave divers are a bit well, you know, mental...

Oh how I laughed when I heard Martyn Farr saying that he didn't like going deeper than 70m 'cause it was too dangerous Ha ha ha haaaa.

Anyway, I see a D5 range coming on :
- Pure side mount for the UK cavers
- Side mount conversion
- Back mounted for the 'normal' people.
Quite an industry in the making.

It was just easier to side-sling the tanks than mount them out of reach. As a backmount the D5+ works very well and adds-on nicely to my standard sidemount rig. Likewise, as a sidemount it would work with backmounted twins of diluent and a side-slung O2.

Going deeper than 180 m is problematic because successful decompression is like Russian Roulette. 70 m is the beginning of the bad terratory as air risks N2 narcossis and O2 toxicity. The D5 has been in-water to 65 m on a "bounce" and extended use at 55 m.

The D5 can do all of the above but I need to address the source of scrubbers (as Caving Supplies have sold out). Am thinking of making a bespoke shorter, fatter version to overcome this as the aspect ratio is a little out. The basic layout is fine.

It would be a nice industry if I had the time to devote to it. As it is, I work in the gas scrubbing business already...

Woz - for deep bailout it needs an ADV. I think you have solved this but the CL case needs more room really - redesigning the scrubber would address this. The issue with the D5 at the moment is that has a greater scrubbing capacity than any commercially available unit and it makes more sense to dive this and rely on your other unit for bailout...

[Woz]

My P-port ADV is ok but it needs a bigger counterlung case to work properly as at the moment it fires too easily as the case interferes with it. I'm working on an alternative solution that's much easier to plumb (literally!) in and based on a bog-standard R190 2nd stage. Possibly. I'm going to have a look in the reg box of shame to see if there are any even easier regs to convert.

Was also going to nip up the local huge surplus depot and see what they have in stock- you never know they might just have something perfect. If not, designing and making a custom scrubber cannister would be pretty straight forward as would be making a radial to fit in the existing unit.

Quick question- what, in your opinion, would happen if the ADV was located at the bottom of the counterlung case, just before the scrubber? Would the additional hydrstatic head from the difference between the mouthpiece and ADV diaphragm make the ADV fire all the time?

[Duncan Price]

Originally Posted by Woz

Quick question- what, in your opinion, would happen if the ADV was located at the bottom of the counterlung case, just before the scrubber? Would the additional hydrstatic head from the difference between the mouthpiece and ADV diaphragm make the ADV fire all the time?

Yes - I tried it on my chest mounted unit. Unless you seriously detune it. The P-port option whereby the mechanical pressure of a collapsed CL fires the valve is the best option rather than relying on a vacuum on the diaphram.

In my opinion an ADV is best situated on the inhale side of the loop but putting it before the scrubber does add enough resistance to draw breath from a downstream CL before it fires.

BTW putting a length of spiral wrap inside the CL will improve matters to stop the CL sealing on the exit - not so much a problem in your unit as you have a plug there.

[louigi]

Watch out folks for the next thrillng installment of Kit Bodger and Hasslhoof in Parts Bin Rumble