My bag of B&Q bits got me hyperoxic and hypercapnic then drowned me! Help! [Archive]

WFO

30-12-2012, 05:30 PM

...Just to get in there first...
No I'm not dead yet. I have every intention of having a good go though.

It was actually reading Dave Sutton's old site "nobubblediving" that got me interested in these contraptions and I'm currently stockpiling bits for a homebuild. I've had a couple of dives on borrowed units and my first step is going to be some pure O2 shore diving on a ray.

So far I've got some gert lumps of ally, a load of fag packet drawings and a bench full of bits of wire and LCD display. Some order may or may not arise out of all this lot and almost certainly by the time I'm done I might as well have bought one, but oh well it's all about the journey :-P

johnny boy

30-12-2012, 07:14 PM

I sort of re-built an IDA-71. lots of step by step pics and info i can supply if required. Tecme was my best source as has been the case for many others. Good move using it as pure O2 to start with. Its Dave Suttons site that got me the bug. Wish he hadnt taken it down. He's over at CCR xplorers.

WFO

30-12-2012, 08:40 PM

Yep I'm on there too.

You can still access all the old site on archive.org
try that
http://web.archive.org/web/20110102101802/http://nobubblediving.com/teardown.htm

Do you dive yours regularly or were you the chap who was selling the one that was painted black?

johnny boy

07-01-2013, 05:54 PM

thanks for the link. glad its still accesible. great site and taught me tons. yes, mine was black and it whisked its way across the sea to ireland like a demented set of eilean pipes.

nickb

07-01-2013, 06:00 PM

I like to fettle, probably more than most, but I'm as interested in building my own rebreather as I am in building my own car.

I couldn't build anything as good as my JJ so why would I bother?

johnny boy

07-01-2013, 06:11 PM

fair enough. i've got it out of my system now anyway. wanted to have a fettle, a rummage, a thrust and a lunge and now i have. i enjoyed building (re-building really) and it taught me a lot, if nothing but knowing your NPT's from your BSP's and JIC's!

Irnbru

08-01-2013, 08:24 AM

Duncan has built a few - he's around on this forum now too. Seem to remember RS (possibly JV) making a small unit about the size of a large mug of coffee, if I come across the pics again I'll post a link to them.

WFO

08-01-2013, 11:21 AM

I like to fettle, probably more than most, but I'm as interested in building my own rebreather as I am in building my own car.

I couldn't build anything as good as my JJ so why would I bother?

Well, because I want to really.

For similar money (I'm not loaded by any stretch of the imagination) I could probably buy an inspo and just go dive it, but I don't like tupperware or eCCR. I can probably build one cheaper but I might have spent a bit more on the incidental shite that you don't end up using.

I've got two ideas, not really committed either way yet, one is a JJ/meg with BMCL copy... I've got some limited access to milling machines and such but it's a big chunk of engineered part to get wrong making the head. That would just go on the top of a cylinder machined to suit, I've got an old ally 10 for the purpose. The other idea is to repurpose an IDA 71 but quite differently from how they normally work, not as good a result but I should be able to make all the bits on my baby lathe, and I've always wanted one.

Good thing is the gas add bits and PPO2 displays would be the same either way so I'm cracking on with those in the meantime.

Digger

08-01-2013, 11:35 AM

Digger

08-01-2013, 11:38 AM

I would also strongly reccomend the Drager FGT scrubber. Really nice design, easily used, contains buckets of lime, very low WOB, lasts forever, and cheap. All the Ray/Atlantis scrubbers I used were average by comparison, and in some cases weren't good enough for deeper diving and wouldn't seal properly.

Digs.

nickb

08-01-2013, 11:48 AM

Couple of things. You want to avoid a metal scrubber, as they conduct heat/cold and condensation tends to build up on the inside of them a lot. Warm gas hits cold ally, condenses, sits in the bottom of the scrubber just waiting to get into the lime.The JJ has an aluminium can and this has never been a problem for me. After a long dive the inside of the can might look like the outside of a glass full of cold lager, but there's never more than an egg cup in total. I keep a circle of fake chamois (Shamwow) in the bottom of the can to soak it it up.

Mark Chase

08-01-2013, 01:13 PM

The JJ has an aluminium can and this has never been a problem for me. After a long dive the inside of the can might look like the outside of a glass full of cold lager, but there's never more than an egg cup in total. I keep a circle of fake chamois (Shamwow) in the bottom of the can to soak it it up.

Thats because the gas is routed arround the scrubber to keep it warm and act as an air gap barrier preventing direct contact heat loss with the external housing

ATB

Simon A

08-01-2013, 02:55 PM

Thats because the gas is routed around the scrubber to keep it warm and act as an air gap barrier preventing direct contact heat loss with the external housing

ATB
What Mark Means is the JJ has a plastic scrubber, it's the outer can that's made of metal.
I would add that when home building Aluminium and sorb don't want to be in direct contact, the aluminium will get eaten.
My first rebreather was a homebuild, you'll definitely get a second hand Inspo Classic cheaper.
If you've still got the home building bug,this will get you started, as is it will kill you, but it has potential Project021017ThreeDollarRebreather (http://web.archive.org/web/20091021182039/http://geocities.com/chickenheadlab/Project021017ThreeDollarRebreather.html)
Simon A

WFO

08-01-2013, 07:06 PM

I'll tot it up when I'm done and probably cry a little :-P

Is there any chance you could tot yours up?

WFO

08-01-2013, 07:13 PM

Couple of things. You want to avoid a metal scrubber, as they conduct heat/cold and condensation tends to build up on the inside of them a lot. Warm gas hits cold ally, condenses, sits in the bottom of the scrubber just waiting to get into the lime.

Second thing is that I've got a 3 cell display, one of the originals made by John Routley, that I'd be happy to sell to a good home - PM me if interested, it has a 3-cell P port "donkey dick" adaptor attached to it that fits K1D cells. If nothing else it has got the board and displays that you will need, and all the wiring is done for you. It is also hard as nails and probably good for 100m+ (it did 85m for me with no issue at all, far better than the KISS housings I had after it which are garbage IMO)

Digs.

The meg and JJ use a metal can, it's not a particular concern as the scrubber itself will be inside an acrylic (or similar) tube coaxially within it.

I've no intention of using the ray scrubber below 6m to be honest, it's just to play about with and get a bit of practice at closed circuit buoyancy.

I'll PM you about the display but since it's interesting, what did you find the K1D cells to be like? Can you still get them and where? Is it just form factor that makes any difference to the R22D shaped ones or does the physically bigger cell last better?

Digger

08-01-2013, 07:30 PM

The K1Ds were fine, but apparently had a shelf life shorter than an R22D. Never had this problem, they ran for 2 years without issue for me. No idea if you can still get them, there was another brand that were the same size I think that might be available. The main reason for using a K1D was that it fits, sideways, through the hole in the middle of a P port, so you could get three in a "donkey dick" configuration sticking into the lung.

If the scrubber is insulated you'll be fine, I'd have avoided having the lime in contact with ally as the condensation in the lime would be an issue - as above there are other metal cans, but they are not simple designs that I'd expect from a homebuild. I still don't really like an ally can when plastic will do it nicely, but I guess it means you don't need a case to protect the plastic etc.

Digs.

WFO

08-01-2013, 07:49 PM

Aye I considered making a P port sensor house but I don't think the wires would fit through the hole at the same time as the sensor once you had them in a tube or something. Maybe some sort of split tube to hold them and single signal wires. Just wish they'd have thought about that when designing the P port! Nice system though.

Hmm.

Still if I go with the IDA 71 bits then I'll make one of the tees a bit fancy and have the sensor access through that, if I go with the megalodon't then they'll be part of the head. No intention of having sorb in contact with ally, it eats it.

Simon A

08-01-2013, 11:16 PM

what did you find the K1D cells to be like? Can you still get them and where?
K1D equivalent from Rebreather, Parts, Service, unique solutions (http://www.tecme.de) part PSR-11-75-D,
You may be able to get a PSR-11-39-TME to fit instead if you can make up some new bits.
Digger,
If you sell him the displays, do they come with the Santa hat you wore when couch testing them?
HTH
Simon A

Digger

09-01-2013, 10:37 AM

Aye I considered making a P port sensor house but I don't think the wires would fit through the hole at the same time as the sensor once you had them in a tube or something. Maybe some sort of split tube to hold them and single signal wires. Just wish they'd have thought about that when designing the P port! Nice system though.

Hmm.

A picture speaks a thousand words.

http://www.tecme.de/bilder/H0600.jpg

and

http://www.tecme.de/bilder/H0600f.jpg

More details here: Sensor House for Rebreather (http://www.tecme.de/sensorhouse.htm) - the wiring is very straightforward, the machined "donkey dick" above is not quite so straightforward. The cage is also fairly critical, otherwise when you pull a negative pressure test or bottom out the lungs they will rub on the face of the cells.

Digs.

WFO

09-01-2013, 12:16 PM

How do people find the molex and cables cope with the environment inside unit?

I was going to crimp and solder the gold molex and fill the back with a bit of hot glue to seal the end from moisture.

That's a nice bit of kit digger, I presume the cage just has an m38 thread in it for the P port

ebt

09-01-2013, 12:30 PM

Soldering often makes them brittle. why not go coax?

WFO

09-01-2013, 01:26 PM

Don't see why not if I have space to use R22Ds, they probably wouldn't suit a P port application though.

chrisken

09-03-2013, 01:27 AM

Building a good rebreather with quality of shop brought unit is only limited by your access to the tools . I have a rEvo which I am in process of selling because I never use it as I prefer my own built . I do have a lathe and mill which I converted to cnc at my disposal. I have built my latest unit on a KISS Tube .It is mccr needle valve O2 addition and I have ADV built into head. Unit holds just under 3kg of sorb and can be fitted with front or back mounted counterlungs. As I have not got a clue how to upload pics to this page via URL you can see them at http://www.flickr.com/photos/cjk24851/:D

WFO

04-06-2013, 11:40 AM

Hey up Chris, your work is very impressive :)

My master plan of IDA 71 didn't happen so I'm running with the meg/JJ/HH inspired unit. It will be more robust anyway.

Big collection of fag packet sketches at the moment but I've just about got the detail of the head parts. Just need to scrounge the use of a decent size lathe to whittle the ID of the cylinder I'm using as a body out to a convenient O ring size and I should be able to make the rest on my baby lathe.

Considering buying T pieces and the counterlung bulkheads as they look a right pain in the tits to make on the lathe, lots of different operations. Expensive parts though...

http://imageshack.us/a/img201/9262/expl1.jpg

WFO

04-08-2013, 01:38 PM

Operation scrounger successful
http://imageshack.us/a/img27/872/xk01.jpg

http://imageshack.us/a/img189/686/b2nc.jpg

http://imageshack.us/a/img534/5369/vcqu.jpg

hubba hubba
http://imageshack.us/a/img202/2733/hau4.jpg

errrr now just considering completely redesigning it and doing away with the can around the sensors instead having them on a flat bulkhead/plate with the backs of them exposed to loop gas... just to make it loads easier to fit the VCD-1000 inside the head. Hmmmm...

notdeadyet

04-08-2013, 05:33 PM

Is that one of those valves that does constant mass flow with a normal, non-capped first stage and the flow won't vary with depth? I remember reading about them on RBW a couple of years ago.

WFO

04-08-2013, 08:28 PM

Is that one of those valves that does constant mass flow with a normal, non-capped first stage and the flow won't vary with depth? I remember reading about them on RBW a couple of years ago.

yup

notdeadyet

04-08-2013, 09:25 PM

yup

Have you given it a go yet? I was looking at one on Ebay the other day that was up for dead cheap and thought about having a punt. Just wondering if they are as good as they are cracked up to be.

WFO

05-08-2013, 08:46 AM

Have you given it a go yet? I was looking at one on Ebay the other day that was up for dead cheap and thought about having a punt. Just wondering if they are as good as they are cracked up to be.

No not touched it yet really was just looking to see how it will fit in the head.

I actually got this for less than buying a swagelok SS-SS2 needle valve

Duncan Price

06-08-2013, 07:59 PM

No not touched it yet really was just looking to see how it will fit in the head.

I actually got this for less than buying a swagelok SS-SS2 needle valve

Do you have details of where you can get them as I would be interested in trying one out.

notdeadyet

06-08-2013, 09:24 PM

Do you have details of where you can get them as I would be interested in trying one out.

This is the one I was looking at: Porter Parker VCD 1000 Variable Constant Differntial Flow Controller VCD1000 | eBay (http://www.ebay.com/itm/Porter-Parker-VCD-1000-Variable-Constant-Differntial-Flow-Controller-VCD1000-/150947754095?pt=LH_DefaultDomain_0&hash=item23252ff06f)