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Sartori Rebreather

Sartori Update

posted Aug 28, 2011, 2:48 AM by Craig Challen   [ updated Aug 28, 2011, 3:32 AM ]

Back into the shed today for the next round of steps in the Sartori CCR conversion. I believe I will be able to test dive it next weekend!

First job today to jump on the lathe and manufacture the insert for the old exhalation port into the head. The oxygen injection will be through here.

Next, install the cable to the electronics, and install the oxygen cells.
This is funny-after deliberating for some time on how to retain/support the cells, I first just shoved them in. Probably would have worked fine but not very elegant. Then, in a flash of inspiration, I got out the hot glue gun and just stuck them on the sides of the cell chamber. Worked a treat!

The modifications to the head complete. Note the following:
1. I have used the Liquivision X-Link and X1 computer for monitoring. The X-Link is no longer available, although I hear rumours that a replacement product is on the way. It was almost unbelievably easy to get working though, just put the Molex connectors on the cable ends, connect the X-Link to the X1, switch on cell monitoring, calibrate and go. Readout seems quite stable.

2. Hose with manual oxygen injection valve. I will use this for testing but likely replace with a KISS valve or similar once the concept is proved.

The rebreather just needs to be reassembled and it can be dived. 
I have not yet embarked on improving gas flow other than in the head, but have several ideas in mind, so this will be the next job after test diving.

Slow progress in Craig's dodgy rebreather workshop

posted Jul 21, 2011, 2:13 AM by Craig Challen   [ updated Jul 21, 2011, 3:16 AM ]

I have been working in fits and starts on the closed circuit conversion of the Sartori. After having dived it as a sidemount passive semi-closed rebreather (PSCR) in April I was happy with the merits of the project. The aim is to have a sidemount rebreather that is easily and quickly convertible from PSCR to CCR.

On stripping and examining the unit it is clear that there are some aspects to the design which will almost certainly increase the effort of breathing. I will attempt to address these as part of the project.

The head stripped off the rebreather with all connections removed. The hose ports seen at the front have an insert that fits into them. In my opinion the inside diameter of these inserts is far too small. We will bypass them.

The head turned over, after I have been doing a bit of artwork on it. 
The hole to the left is coming from the exhalation port. The one on the right was the same as this but I have enlarged it to fit 3 oxygen cells. This should have been done with a milling machine but since I don't have one I used a hand-held die grinder. A pretty rough job I'm afraid, but it will do.

For sidemounting I want the hoses to come from the top of the head, not from the front as originally as the hoses will point in the wrong direction and will be too vulnerable. Here I have drilled holes for the hose mounts.

The hose bases attached. I have used hose bases from the Megalodon rebreather. Above them is the gland through which the cable for the oxygen monitoring will pass.
At the lower left I have replaced the insert into the original inhale port with a blanking cover, since the port is no longer required. The other port will have the oxygen injector attached as the next step (stay tuned for the next exciting installment).

Forthcoming new rebreathers

posted Jul 21, 2011, 2:11 AM by Craig Challen

Our Sartori PSCRS are taking shape in the "factory". Note the shotgun in the corner to ward off possible industrial espionage from other companies who desire this high tech machine.

We hope to take delivery of 7 units by the end of February 2011, and then the training will begin!

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