SCR Trimix

**Freef** · 1st March 2007, 22:08

I've been having a ponder, to save duplicating the posts see the below, and if anyone has a better way of doing it let me know. Ta

http://www.rebreatherworld.com/semi-...r-dolphin.html

O.C.Diver · 2nd March 2007, 01:03

It can be done; it has been done; the few divers I know who have done it have moved up to CCR. SCRs are fine down to 100' or so. By the time you need to put helium in the mix, you will also need to start thinking about deco. If a true CCR is financially out of the question, think about converting your Dolphin. Diving an SCR with trimix is like sex with your clothes on, you can do it, and that's about all that can be said for it.

Ted

gathan · 2nd March 2007, 02:24

Quote: (Originally Posted by O.C.Diver)

It can be done; it has been done; the few divers I know who have done it have moved up to CCR. SCRs are fine down to 100' or so. By the time you need to put helium in the mix, you will also need to start thinking about deco. If a true CCR is financially out of the question, think about converting your Dolphin. Diving an SCR with trimix is like sex with your clothes on, you can do it, and that's about all that can be said for it.

Ted

I've done quite a few 250'+ dives with this SCR Ted

**wedivebc** · 2nd March 2007, 03:19

Quote: (Originally Posted by gathan)

I've done quite a few 250'+ dives with this SCR Ted

yeah but I bet you couldn't afford to buy one.

gathan · 2nd March 2007, 03:36

Quote: (Originally Posted by wedivebc)

yeah but I bet you couldn't afford to buy one.

You'd be right here Dave...

Andre

gibbogeo · 2nd March 2007, 13:19

Quote: (Originally Posted by Freef)

if anyone has a better way of doing it let me know

When i used helium in SCR on my dolphin, i used a different formula that is not better and give the same results:

FHe[loop] = (100-FO2[loop]) * FHe[cyl]/(FHe[cyl]+ FN2[cyl])

(all in "%")

disclaimer part:

I don't suggest anyone to use the Dolphin with different gases and jets than the one stated by the manufacturer. It is dangerous and not worth the risk.

Moreover, if someone is not able to think this calculation by himself, i believe that he should stay far away from experimenting with helium in Dolphin.

disclaimer end

Said that, having tried personally i think that a conversion to CCR is easier, there are many different way to do it, plenty accessories for the transformation are available and the results is more satisfying.

**Freef** · 2nd March 2007, 19:24

I find that the variables in planning trimix dives with SCR make the exercise a little too open to errors or problems for seriously deep diving. Using the formula devised I find that I would be getting close to 30% He in the loop with 26% O2.

This is too long for Dick and too short for Richard for deep diving, but there may be an application for the 40-50m range. At the moment it's the theory on the gas side I am looking at, and it looks OK so far. I'll not be doing any practical experiments until a lot later in the year and then with 10% He to start in the shallows-with plenty of bailout.

CCR trimix is the way to go for most diving in this range, but I'm interested in the theory side of things long before I get involved in diving the more entertaining gasses.

Thanks for all the input so far.

narked at 90 · 2nd March 2007, 23:53

hi david, you already know what im going to say! convert it to ccr it makes it sooo much nicer with out all the calcs to boot.
you know im only down the road if you need any help
personly i just ran mix in my unit and didnt think to much about it

but every one should do things there own way and not copy me

kind regards john routley

**Freef** · 3rd March 2007, 08:29

Hi John,

I'll probably go KISS at some point in the next 2-3 years, I'm interested in the theory at the moment, possibly some practical stuff in the shallows later this year. i don't think I would have the bottle to dive it deeper than about 50m anyway!

How are you getting on with the laser cutter? How many mW/W does it put out?

narked at 90 · 3rd March 2007, 10:35

Quote: (Originally Posted by Freef)

Hi John,

I'll probably go KISS at some point in the next 2-3 years, I'm interested in the theory at the moment, possibly some practical stuff in the shallows later this year. i don't think I would have the bottle to dive it deeper than about 50m anyway!

How are you getting on with the laser cutter? How many mW/W does it put out?

Hey David that is a very refreshing thing to hear...some one being honest and not all the chest beating that goes on on here, have a GREEN
the laser pumps out 30WATTS cw(constant wave) but pulses to 150 Watts!!!! more than enough to bash holes in stuff

but I've just found some thing even more dangerous to play with! pictures and video to come....if i survive
kind regards john routley
www.narkedat90.co.uk

1st March 2007, 22:08	#1 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,425	SCR Trimix I've been having a ponder, to save duplicating the posts see the below, and if anyone has a better way of doing it let me know. Ta http://www.rebreatherworld.com/semi-...r-dolphin.html __________________ David. Diving the mahogany rebreather.
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2nd March 2007, 01:03	#2 (permalink)
O.C.Diver Helium Addict Current Rebreather/s: Classic Kiss Other CCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Home Build Join Date: Mar 2006 Location: Salisbury MD USA Summers; Wandering Florida Winters Posts: 244	Re: SCR Trimix It can be done; it has been done; the few divers I know who have done it have moved up to CCR. SCRs are fine down to 100' or so. By the time you need to put helium in the mix, you will also need to start thinking about deco. If a true CCR is financially out of the question, think about converting your Dolphin. Diving an SCR with trimix is like sex with your clothes on, you can do it, and that's about all that can be said for it. Ted __________________ Consider this my opinion.......sometimes I'm even right, but remember.........YMMV. Ted Green Charter Boat "OC Diver" http://www.ocdiver.com
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2nd March 2007, 02:24	#3 (permalink)
gathan MixedGas Current Rebreather/s: Classic Kiss Other SCR Other Rebreather/s: Other SCR Join Date: Sep 2005 Location: Tottenham, Ontario, Canada Posts: 194	Re: SCR Trimix Quote: (Originally Posted by O.C.Diver) It can be done; it has been done; the few divers I know who have done it have moved up to CCR. SCRs are fine down to 100' or so. By the time you need to put helium in the mix, you will also need to start thinking about deco. If a true CCR is financially out of the question, think about converting your Dolphin. Diving an SCR with trimix is like sex with your clothes on, you can do it, and that's about all that can be said for it. Ted I've done quite a few 250'+ dives with this SCR Ted
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2nd March 2007, 03:19	#4 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,507	Re: SCR Trimix Quote: (Originally Posted by gathan) I've done quite a few 250'+ dives with this SCR Ted yeah but I bet you couldn't afford to buy one. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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2nd March 2007, 03:36	#5 (permalink)
gathan MixedGas Current Rebreather/s: Classic Kiss Other SCR Other Rebreather/s: Other SCR Join Date: Sep 2005 Location: Tottenham, Ontario, Canada Posts: 194	Re: SCR Trimix Quote: (Originally Posted by wedivebc) yeah but I bet you couldn't afford to buy one. You'd be right here Dave... Andre
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2nd March 2007, 13:19	#6 (permalink)
gibbogeo Gilberto Bonaga, Italy Current Rebreather/s: Classic Kiss Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Sep 2005 Location: italy Posts: 332	Re: SCR Trimix Quote: (Originally Posted by Freef) if anyone has a better way of doing it let me know When i used helium in SCR on my dolphin, i used a different formula that is not better and give the same results: FHe[loop] = (100-FO2[loop]) * FHe[cyl]/(FHe[cyl]+ FN2[cyl]) (all in "%") disclaimer part: I don't suggest anyone to use the Dolphin with different gases and jets than the one stated by the manufacturer. It is dangerous and not worth the risk. Moreover, if someone is not able to think this calculation by himself, i believe that he should stay far away from experimenting with helium in Dolphin. disclaimer end Said that, having tried personally i think that a conversion to CCR is easier, there are many different way to do it, plenty accessories for the transformation are available and the results is more satisfying.
(Online)

2nd March 2007, 19:24	#7 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,425	Re: SCR Trimix I find that the variables in planning trimix dives with SCR make the exercise a little too open to errors or problems for seriously deep diving. Using the formula devised I find that I would be getting close to 30% He in the loop with 26% O2. This is too long for Dick and too short for Richard for deep diving, but there may be an application for the 40-50m range. At the moment it's the theory on the gas side I am looking at, and it looks OK so far. I'll not be doing any practical experiments until a lot later in the year and then with 10% He to start in the shallows-with plenty of bailout. CCR trimix is the way to go for most diving in this range, but I'm interested in the theory side of things long before I get involved in diving the more entertaining gasses. Thanks for all the input so far. __________________ David. Diving the mahogany rebreather.
(Offline)

2nd March 2007, 23:53	#8 (permalink)
narked at 90 John Routley Current Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Other Rebreather/s: Other CCR Dolphin Home Build Join Date: Feb 2005 Location: middlands uk Posts: 1,073	Re: SCR Trimix hi david, you already know what im going to say! convert it to ccr it makes it sooo much nicer with out all the calcs to boot. you know im only down the road if you need any help personly i just ran mix in my unit and didnt think to much about it but every one should do things there own way and not copy me kind regards john routley __________________ *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Narked at 90 Go Military
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3rd March 2007, 08:29	#9 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,425	Re: SCR Trimix Hi John, I'll probably go KISS at some point in the next 2-3 years, I'm interested in the theory at the moment, possibly some practical stuff in the shallows later this year. i don't think I would have the bottle to dive it deeper than about 50m anyway! How are you getting on with the laser cutter? How many mW/W does it put out? __________________ David. Diving the mahogany rebreather.
(Offline)

3rd March 2007, 10:35	#10 (permalink)
narked at 90 John Routley Current Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Other Rebreather/s: Other CCR Dolphin Home Build Join Date: Feb 2005 Location: middlands uk Posts: 1,073	Re: SCR Trimix Quote: (Originally Posted by Freef) Hi John, I'll probably go KISS at some point in the next 2-3 years, I'm interested in the theory at the moment, possibly some practical stuff in the shallows later this year. i don't think I would have the bottle to dive it deeper than about 50m anyway! How are you getting on with the laser cutter? How many mW/W does it put out? Hey David that is a very refreshing thing to hear...some one being honest and not all the chest beating that goes on on here, have a GREEN the laser pumps out 30WATTS cw(constant wave) but pulses to 150 Watts!!!! more than enough to bash holes in stuff but I've just found some thing even more dangerous to play with! pictures and video to come....if i survive kind regards john routley www.narkedat90.co.uk __________________ *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Narked at 90 Go Military Last edited by narked at 90 : 3rd March 2007 at 21:12.
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