P1SS update

[Digger]

Well, after some long hard thought, I've modified the P1SS. We've worked out that the mouthpiece I've got now is from an Azimuth, and we found some parts which fit it nicely from Focus. The breathing hoses and one way valves are now in place, albeit after some fighting, and now I have a bag, scrubber, hoses and mouthpiece. None of the components leak, but I can see some problems putting them all together.

Now, this is where you guys come in. I'm looking for some more breathing hoses. Does anyone have any they've replaced? Any good sites to buy this sort of thing by the metre? I had a look at some Inspiration hoses on Sunday, and they do the job I think, but it's going to have a mark-up from AP, and they must be buying it in from someone. We found the webbing suppliers, so this sort of thing must be available somewhere. I'm also figuring the sort of place to supply AP and others must have a fair few sizes available, so I can pick and choose what I want to use.

So, this will be the P3SS, the scrubber is now upright (I figured this better from the point of view of any water gathering in the bottom and preventing the whole thing going nasty, and to make that cocktail a bit less likely) and now it has twin hoses. What it does need if you ask me is twin counterlungs, but that's going to take some modifications. The ABLJ is getting welded down the middle and my lungs will be left and right inside the bag.

One other one that someone might be able to help with - has anyone got an Inspiration case they don't need, can lend or sell, or have broken enough for them not to bother fixing? It's just I'd really like to see the faces of a few people when the Expiration is lettered down the back and I've got my little setup in there.

Is there a source for boxes which will fit 6l tanks? It's what I've got, and I'd say having a bit of extra onboard for bailout (considering the nature of this beast) might not be a bad thing at all.

So basically, if the logic's flawed in any of this, someone please shoot it down, because right now I reckon I'm close to a design I'm almost happy with. And I appreciate your advice on this.

Oh, and anyone thinking about doing anything like this, Bozenic's book is worth it's weight in gold. And that would be a fair bit of gold, too!

[wreckweasel]

Digs,

Inspy hoses are corrugated all the way to the end. You'd do better with kiss hoses or the hoses that tubbs sells (flat ends). Failling that... how about a set of draeger hoses and fit em into your scrubber using the quick connects.

/Z

[Duncan Price]

Originally Posted by Digger

Well, after some long hard thought, I've modified the P1SS. We've worked out that the mouthpiece I've got now is from an Azimuth.

Actually its a LAR V mouthpiece.

Originally Posted by Digger

So, this will be the P3SS, the scrubber is now upright (I figured this better from the point of view of any water gathering in the bottom and preventing the whole thing going nasty, and to make that cocktail a bit less likely) and now it has twin hoses.

You really need a bigger scrubber. The P1SS one is too small for extended use at depth. I had a CO2 hit on it after an hour at 20 m.

mind how you go

[Padowan]

Make sure that the welding you do on the bladder to make it into 2 lungs is really solid and sound as you will get a CO2 hit pretty quick if there's a break/breach of this weld. You might be safer trying to source a second bladder or completely cutting it in half and seperating it (if it's a double bag construction) as this will completely isolate each lung.

Never built a RB, but thought a lot about it, and this is the kind of stuff I'd be concerned about.

Be Safe....

[NotDeadYet]

Padowan said it before I got there. I'd be very wary with the bladder and I'd be tempted to split it completely also. You do need a bigger scrubber too, my Draeger Ray scrubber is about the same size as the P1SS and I've had a sore head after 25min with a half fill. That was shallow and not even working particularly hard in warmish water (18degC).

Try www.danshop.com for hoses. Zak is right, the ones with the cuffs are easier to work with. These are injection moulded so are generally available in stock lengths rather than cut to size. The AP hose uses a special end fitting, regular hose you can just jubilee clip. Oxycheq also sell hoses.

These guys are closer to home (near Aberdeen) and do hoses for twin hose regs. These should also work but may be narrower than what you want. Nice green ones though!

What you really need to be looking at soon is some kind of ppO2 monitoring system. The electronics are reasonably easy if you can find a display that is easy to work on (the hard part) and then you need to house it. Even when diving in O2 mode having a display gets you into the habit of looking at it and using it. It can also be quite surprising if you use it after doing a normal dive when you see how much crap you are offgassing into the loop.

I know why you want an Inspiration case!!! You just don't want any hassle from the clipboards at Stoney or the NDC!!! Make a plywood mould and try fibreglassing a case.

Welcome to the wonderful world of homebuilding, the next time someone who doesn't know better tells you its cheap you can show them your VISA bills!!! My car is currently shagged so there goes my RB budget this month

Cheers,

Stuart

[Digger]

Cheers for your responses guys. I've been thinking a lot about it, and priorities right now are doing something about stopping water getting into the scrubber, then ppO2 monitoring, then needle/KISS valves.

In O2 mode I'm currently flushing it every 10 minutes or so just to make sure what I'm breathing is either O2 or nearly O2.

The welding will either be a serious job of it, or I'm going back to my idea of 2 inner bags in an outer bag. Not ideal, but I just can't afford to be buying expensive fancy counterlungs. Mind you, if I got some which looked like the YBOD, and I had the case, there would be very little to tell it apart. Except the lack of handsets and mouthpiece.

Lar V mouthpiece. Interesting. I've not seen a Lar V in the flesh. Might try and find someone with one, they might have some nice parts I could use!

The scrubber will be updated asap. I'm currently limiting it to under an hour at less than 6m, but when the time comes it will be replaced or modified. How long a scrubber could I get away with at the diameter do you reckon? Is it worth it? WOB is pretty low right now, so it would be ok to make one a few inches longer? I could get some of that pipe easy enough, and machining it won't be difficult. Endcaps can stay that way too.

[Digger]

Now those hoses look good. The ones I've used a tthe moment are old ones from a twin hose, and they're much bigger than the ones I was going to use, so should be fine.

I think Green will look nice. Especially on the O2 unit....

Oh, and I can repair that twin hose that's in the garage! Anyone for a historic dive day? Isn't there one at Stoney every year? I've got the mask and everything.

[NotDeadYet]

Try the 3L Flexi Flask bags from The Gorge Outdoors for breathing bags. They are only about £6 each and the cap can be used for draining afterwards. I fitted a p-port on to mine for easy connection to the hoses. Otherwise you can use skin fittings from a chandlers.

Or try some lay-flat hose, it isn't too expensive either. You need to clamp the ends. They are known as "Jason" bags after the Aussie inventor of them. Have a look at some of the AARG guys, they use them in over the shoulder set up.

But you're right, keeping water out of the scrubber is a pretty big priority!!!

[turbanator]

Originally Posted by NotDeadYet

But you're right, keeping water out of the scrubber is a pretty big priority!!!

I'm very new to this, like zero knowledge of building the things, but could you not pack the scrubber into a hydrophobic membrane that would allow air to pass through?

Would this increase the WOB beyond practicality?

Can't believe I'm the first to suggest this, so there must be a reason why not!

r
Paul

[Duncan Price]

Originally Posted by Digger

The scrubber will be updated asap. I'm currently limiting it to under an hour at less than 6m, but when the time comes it will be replaced or modified. How long a scrubber could I get away with at the diameter do you reckon? Is it worth it? WOB is pretty low right now, so it would be ok to make one a few inches longer? I could get some of that pipe easy enough, and machining it won't be difficult. Endcaps can stay that way too.

I had a scrubber whcih was the same pipe but twice the length. It's WOB was crap so I threw it away.