Important features when choosing a rebreather

[Wibble]

with the clicky ones you can typically just remember the number of clicks from "off" that you need for deco and then adjust as your ppO2 starts driving. Drifting up, turn it back a click, drifting down then turn it up a click. If you have a blocked first stage then it is not depth dependent, just workload dependent and the Fathom uses this approach albeit without a clicky needle. When you have a normal needle, the process is the same just without the detents to tell you where it is located.

Assume there's some mild quirks to this; when deep it'll need winding in (as the IP will be much higher than when shallow).

Do like the click concept; that would seem easy enough to twiddle.

Don't suppose you have a link to an example?

Would be great if the Revo had this on the excellent injection block.

 

[Wibble]

Thanks a lot for your suggestions! It really sounds like SM CCR is not the way to go. I will then consider BM CCR and SM the bailout bottles

As a convert to CCR for one year, I'd definitely tell my previous self that your first year's all about getting used to life with CCR. It's a ton of subtle things you need to be able to deal with, from learning all the different ways it will kill you, to sorting out your core skills, the endless ascent challenges (probably the busiest time on a CCR), and thinking in advance.

A year in and 100 hours and MOD2 under my keel and I know there's much more to finesse. Even though I feel very comfortable with the unit I know that complacency is the enemy. That shortcut or known problem that comes back to bite.

One thing which is extremely different from OC diving is you'll end up banking gas. Twinsets of oxygen, air and deep diluent are in the garage. Seems that mixing gas is all part of the build process, especially for deeper dives.


Choose something common, standard and where you have people around you using it. Look at the boxes on your dive boats: JJs, Inspos, Megs, Revos and the less common ones: Kiss, X-boxes, etc. Have *never* seen a sidemount rebreather.

 

[grantctobin]

Assume there's some mild quirks to this; when deep it'll need winding in (as the IP will be much higher than when shallow).

Do like the click concept; that would seem easy enough to twiddle.

Don't suppose you have a link to an example?

Would be great if the Revo had this on the excellent injection block.

The problem with the Revo injection block (other than that you could club a seal with it), is that it’s not serviceable if you get something stuck in the orfice because it’s pressed in. Yes, you can put it in an ultrasonic for 24hrs and pray but they’re pretty one and done.

The click is great, as are the dual orfices. Pic borrowed from Kakuk to show the single button and dual button.

 

[Wibble]

The problem with the Revo injection block (other than that you could club a seal with it), is that it’s not serviceable if you get something stuck in the orfice because it’s pressed in. Yes, you can put it in an ultrasonic for 24hrs and pray but they’re pretty one and done.

The click is great, as are the dual orfices. Pic borrowed from Kakuk to show the single button and dual button.

Numpty question... Where are they listed if one wanted to buy one?

 

[grantctobin]

Numpty question... Where are they listed if one wanted to buy one?

They’re not, really. That’s the downside.

 

[rddvet]

Assume there's some mild quirks to this; when deep it'll need winding in (as the IP will be much higher than when shallow).

Do like the click concept; that would seem easy enough to twiddle.

Don't suppose you have a link to an example?

Would be great if the Revo had this on the excellent injection block.

I love my needle valve. It’s very easy to use and perfectly match your metabolic function. I have the fathom so I don’t have the clicks. I have no issues without clicks. I know the flow I get from a 1/4 to a 1/2 to 2 full twists. It’s easy muscle memory and not an issue. The fathom uses a blocked first stage with an io set over 200. The spring in the first stage is a special spring (forget what metal) that allows the unit to be dove to 300 feet without losing oxygen flow. We never go that deep so my wife is using a blocked reg with a normal spring with the ip set to 150. Not an issue at all. And I’ve used unblocked firsts when my hp seat failed (apeks is ****) and it was a nonissue to 120ft

 

[flymolo]

Assume there's some mild quirks to this; when deep it'll need winding in (as the IP will be much higher than when shallow).

With a blocked first stage the IP remains constant so you don't need to adjust the needle for depth.

 

[tbone1004]

Assume there's some mild quirks to this; when deep it'll need winding in (as the IP will be much higher than when shallow).

Do like the click concept; that would seem easy enough to twiddle.

Don't suppose you have a link to an example?

Would be great if the Revo had this on the excellent injection block.

you need to turn it down if you are not using either a blocked first stage, or the dual CMF. The blocked first stage like the Fathom uses gives you a constant IP, and the dual CMF like the KISS uses essentially gives you the same effect *CMF, Needle, CMF*.
The KISS variant as linked by @grantctobin is not available for sale to the general public.

 

[rddvet]

you need to turn it down if you are not using either a blocked first stage, or the dual CMF. The blocked first stage like the Fathom uses gives you a constant IP, and the dual CMF like the KISS uses essentially gives you the same effect *CMF, Needle, CMF*.
The KISS variant as linked by @grantctobin is not available for sale to the general public.

The fact that I could only get the regular needle valve on the sw as opposed to the actually really good one annoyed me. Even getting their regular needle valve was going to be a pain. Since I was already used to a needle valve, Edd was going to get me one if I had bought the unit. At the time he didn't sell them to everyone I believe because there weren't a ton of them available. That may have changed since

 

[Zebra 1]

Thanks a lot for your suggestions! It really sounds like SM CCR is not the way to go. I will then consider BM CCR and SM the bailout bottles

I was in your position not long ago and suggest you read:

Making the leap: help choosing first rb

Tedious read but a lot of good input from Scubaboard members here.