IDA-59: A report of my first dives

matti_anttila

Hi All in the Rebreather World forums,

Yesterday I had my first dives with my IDA-59, which I bought October,
this year. I have photographs, testing and diving reports on my IDA-59
web page:
Matti's IDA-59, Russian mechanical Trimix CCR

I have training for the AGA ACSC, Carleton Viper SC (nitrox), and I have
a few intro dives with Inspiration. But IDA-59 was something totally new
Something brutal, odd, but still a great fun! In the future I will add a
ppO2 meter and do some more configuring, but it was nice to test the
system "as it is".

Safe and happy diving!

Matti Anttila
Finland

bathtub

now that is a scary looking beast !
training training and more training to be happy with it I guess, with all those different sources of O2 I would want 02 cells all over the system to try and work out what the hell was going on !
Good Luck, and as you say--- dive safe....

divingtoors

HI Matti

Very interresting...
I would like to see more results of diving
I am in process of re-building an IDA-71 which is very similar to the IDA-59 in concept and parts

I am very impressed with the PPO2 monitoring handset.
Looks as tough as a tank...

Do you have any plans / instructions you could forward to me for building one of the handsets, as this is the only hassle that I am still sitting with.

Best regards

Johan

matti_anttila

Hi Johan!

Well, I am still in a process of constructing the T-piece for the ppO2
module. I thought that it would be easiest way to install a P-port into
the counterlung, but as a second thought, the inhale tubing of IDA-59
is routed so that I really want the analysis be done in the inhale tube.
So that's still something I have to do.

The handset was time-consuming, really.. Not the work itself, only, but
finding the parts. I managed to find aluminium boxes with O-ring readiness
for ~5 euro! They sure looks tough and good for this purpose. Then I bought
some O-rings, made the display hole and holes for the connections etc.
You can try to ask, if the shop that sold the aluminium box is willing to
post those to SA
PARTCO OY - Elektroniikan komponenttien erikoisliike
(o-ring size is 2.5mm (thickness) x 90mm (diameter) )
The O2 analyzer module is OxyCheq El Cheapo, which can be configured to
show ppO2 instead of %O2. The O2 cell seems to be the same that is in
Ouroboros, so it should be OK in pressure.

As mentioned in my web page, I let the handset interior be in ambien
pressure to avoid implosion/leak risk. That's why I use normal regulator
low-pressure hose in the handset - T-piece -connection, in which the
electric wires for the O2 cell go also.

The switch has DiveRite (Wreck canister) rubber boot and the fine-tuning
trimmer's connection is self-made with some o-rings and bolts & washers.

I wish you good luck with your IDA!

jaap

Why not simply modify the T-piece on the inside of the bag on the inhale side? If you remove the internal rubber hose that goes from the srcubber to the T-piece (inhale side) you will now force all the gas/intruding water to go by the bag before you inhale it.

If you then even plug the lower hole on the internal T you force all inhale gas to be taken from the top of the bag around the ADV.

I found out that the original configuration is very good at surprising you with some caustic cocktails. It takes very little water to have it go to your mouth if you dive horisontal, and its hard to notice before you taste it... I guess they did not care about watertraps since it was used with a FFM?

If you modify the unit to allow the bag to act as a water trap not only do you have the chance that the OPV will dump some but you would probably have to accumulate quite alot of water before you inhale any. And by then you would already have noticed what is going on from the gurgling and increase in WOB.

__________________
My initials: JAAP

matti_anttila

You mean like this (image attached)? That's a good idea, because I was also
very afraid of the water entering the inhale side, should the scrubber get water in.

Attached Images

Modified_breathing_tubing.jpg (273.8 KB, 184 views)

jaap

Yes!

Of course the whole thing could be improved in many ways. The diameters of the hoses and couplings are rather small. There is really no form of watertrap on the exhale side. I would prefer a design that at least can catch some small ingression of water/dribble before the scrubber.

Also if you want to modify it further the connector at the ADV is a regular R-1/4. Its a std penumatic fitting, at least here in Sweden. So it would be easy to put some form of quick-connector there to allow gas to be taken from say a sidemount or backmount. Cells can go into the bag via P-conn. And some form of CMF-flow (O2 for mccr or mixed gas for SCR) could be introduced via the other connector or via the fillingplug to the scrubber. That way you get rid of the chestmounted cylinders.

I'm doing the above things on my IDA-76. A drawback is the relatively small scrubber.

__________________
My initials: JAAP

matti_anttila

I finally managed to finish my ppO2 meter and made a test dive with it:
(images of the system): Matti's IDA-59, Russian mechanical Trimix CCR

I constructed a T-piece to the inhale tubing and it seemed to work.
However, I think that the cell placement is not very optimal yet, since the
reading changes a little bit behind with the estimated loop ppO2, so I
assume it takes some time that the cell space flushes with current mix.

IDA-59 has already a plug for off-board diluent, and I use a regular AGA Airi
mask's LP hose fitting there (it fits perfectly). However, this gas also goes
to the same system, so no dil flush can be made other way than using
the ADV. And since the ADV is placed in one's neck, facing down, the only
way to "manually" use it is to purge the loop and inhale so that ADV
activates.