Sheerwater vs VR3 for an EVO 4th cell?

**Dave Sutton** · 16th February 2007, 14:09

Quote: (Originally Posted by Mdemon)

As for your DSV/BOV/HUD/4th cell, you need to complete the job and add the ADV to it.

I'll look at the ADV as a feature as well, all one would need to do really is to have the BOV selector select exhaust valve "on" as well as loop "off" and vice versa and the same second stage could do both jobs. Let me do a little thought on that. Could be delivered Tuesday if you would like to post a suitable R&D/Production fee today, Let's say.... 10K sterling would motivate me to give up the weekend... shall I forward my bank details?

Probably the way to do this would be to remote the electronics for the HUD with a cable up the inhale hose to the rig. My original system carried the HUD board and the battery under the DSV. With the second stage added I think that the form factor would get a little large for practical use.

Dave

**fireman** · 16th February 2007, 15:44

On a slightly relevant note, I saw the heads up mask at OWUW, very slick if somewhat expensive and perhaps over complicated. Hypothetically one could have all the info you wanted right there, and video games for deco...

divetheworld · 16th February 2007, 18:04

[quote=divetheworld;96726][quote=JonnyB;96724]

Quote: (Originally Posted by divetheworld)

Yup, the Shearwater will parallel with any unit that I have encountered because it has a very high internal resistance.
It will not affect the APECS, and the APECS will not affect it.

The software routine for calibration is matched for the Meg perfectly too.

However............

As Bruce has just informed me there is no hole in the head to allow it. There are three holes, primary, secondary and HUD.
You would have to do a little work to fit it like fitting your own gland to a user made hole.
If you do decide to go this route, give Bruce a shout as he has plenty of experience his electrickery and Megs! Its worth getting advise from those that know, rather than those who have half the picture like me.
Alternatively, the Shearwater meg conversion..........

Brent

seppu · 18th February 2007, 15:52

hai
ist a bit of topic,but sometimes helpful.there is a picture from my permanent fitting revodreamholder on a shearwater.i dont like the brig on my hand

gruss sepp

NickK · 25th February 2007, 16:24

Quote: (Originally Posted by Gill Envy)

thank you everyone for your feedback on and off line.

I'm veering toward the sheerwater at this point for the following reasons:
-better match of deco with the vision
-extremely efficient on batteries, which just seems like a sign of a well engineered system.
-Build quality is impressive
-auto on switch
-HUD option
-very intuitive screen layout
-back light does not suck up the battery...can be left on a lot.
-manufacturer is on the way to some of my favorite diving!
-When i graduate to home building it can be my primary

just kidding

Hi Gill,

Glad to see you are on right truck. The Shearwater computer the way to go.
Why to waist money just to get PPO2 monitor if you can get "full meal deal" with Bruce's computer. PPO2 monitor, deco computer, also O2 solenoid controller for your next home built project. All in one, so far no reported problems with it, even display info close to Vision with matched GF algorithm (best match on the market IMO), and, according to my friends on Vancouver Island, Bruce is a fine gentleman and active diver, also in our neighbourhood. No hidden costs, secret pins or other PITA issues.
What for fittings, personally I am using John's 4th cell adapter with future provision to use sensors in this configuration: 1-2-3 (as per factory default) for Vision and 1-4-3 for Shearwater. In about of week time will have an answer from one of our suppliers if they can supply me "V" adapter coax cable with SMB connectors make Shearwater connections to Vision's head O2 sensors easy, without any changes to original configuration.
Let us know of your honest opinion on GF when you will start using it.

Nick

P.S. Moving to Vancouver Island - NA North West Mecca of Scuba Diving - in April and hope my ali boat will be built by September - October, as promised, so we can meet one day and go for some nice dives.

**Gill Envy** · 25th February 2007, 20:30

Nick, thanks for your thoughts. Glad to hear you are moving to this neck of the woods. By all means look us up when you move out this way for some diving. I head up to BC several times a year.

I have been contemplating hooking up the Shearwater GF the way you suggest, to two of the three vision cells. It's only natural to want to want to unleash the Shearwater. My reluctance in pursuing this approach is that it goes against the "isolationist" approach that Dave and others have convinced me has Merritt.

Here is my current understanding:

So the theory goes: if salt water ingress or some other short causes voltage irregularities, I don't want there to be a chance that the Shearwater will get polluted with errant current.

This of course has to be balanced with the fact that with only a 4th cell connected to the GF, you have no voting logic for comparison. I'll take on the isolationist theory here, as well as I can (Dave et all chime in if I go astray), even though the jury is still somewhat out for many of us on weather or not cross over voltage contamination between cells to a back up system is really a possibility.

The thinking goes: except in an emergency, you are not relying on the fourth cell, your're mostly relying on the primary. I think we can all agree, a single fourth cell has limited value and would only be relied entirely upon with significant caution and for short duration.

In the isolationist paradigm of independent system cross check, the 4th cell would be there primarily to alert one to discrepancy... no shared batteries, no shared cells. In the instance of significant discrepancy, you'd do a flush and determine which cells/cells to believe while you end the dive. The only time you'd be relying on the 4th cell entirely is to the surface and end the dive...

to the isolationist, the value of total independence outweighs the temporary hazard of bailing with the 4th cell...which you'd only do if you can verify proper functioning with a flush, and then of course there is always your OC BO bottle, when all else fails.

The 4th cell would be verified for voltage limiting at the beginning of the dive with the rest of the cells and replaced if it goes AWOL before continuing to do the dive. It seems to me that the value of the 4th cell and totally isolated system is that you never really look at your electronics as a whole, but two separate systems to cross check. On the vision, if there is no HUD display blinking, no buzzers buzzing, and all three cells are pretty much in the same ball park, it's all too easy to assume everything is OK and not really be critical in one's thinking...to even become lulled into complacency. I'm hoping that having a totally isolated system will help instill critical thinking habits on top of the added benefits of redundancy. Isolation in redundancy is one of the elements in mCCR's, the KISS in particular, that i am convinced contributes to their zero fatality rate and merits integration in eCCR's.

To date, I know of one common failure point in the vision electronics that can lead to a total system failure. If B1 fails suddenly (Wrong battery brand or I suppose a bad battery) the hand off mechanism to B2 can become disabled... if you want an example of that open up the battery compartment, hold the batteries in place while you power up...go through the start up and then allow the battery from B1 to drop out...screen goes blank, B2 does not take over. Voltage cross over to the back up controller through the o2 cells may turn out to be a second, yet seemingly a more obscure possibility.

In any case I love the vision electronics, am happy it has one screen and some built in redundancy, but am also pretty convinced of the wisdom of a truly isolated, independently powered and independent o2 cell guided back up system regardless of what rebreather I could have chosen...and am happy to have that system be a completely different brand than the primary.

g

Quote: (Originally Posted by NickK)

Hi Gill,

Glad to see you are on right truck. The Shearwater computer the way to go.
Why to waist money just to get PPO2 monitor if you can get "full meal deal" with Bruce's computer. PPO2 monitor, deco computer, also O2 solenoid controller for your next home built project. All in one, so far no reported problems with it, even display info close to Vision with matched GF algorithm (best match on the market IMO), and, according to my friends on Vancouver Island, Bruce is a fine gentleman and active diver, also in our neighbourhood. No hidden costs, secret pins or other PITA issues.
What for fittings, personally I am using John's 4th cell adapter with future provision to use sensors in this configuration: 1-2-3 (as per factory default) for Vision and 1-4-3 for Shearwater. In about of week time will have an answer from one of our suppliers if they can supply me "V" adapter coax cable with SMB connectors make Shearwater connections to Vision's head O2 sensors easy, without any changes to original configuration.
Let us know of your honest opinion on GF when you will start using it.

Nick

P.S. Moving to Vancouver Island - NA North West Mecca of Scuba Diving - in April and hope my ali boat will be built by September - October, as promised, so we can meet one day and go for some nice dives.

laurawood · 31st March 2007, 11:32

I don't believe that the shearwater electronics fits the new co-axial connections installed with the new O2 cells. I have a new loom & the new cells on my inspo classic & wanted to install a HUD (as I lost both handsets on a dive recently due to battery bounce with no warning that no O2 was injecting). Bruce informed me that at present the only option would be to run the HUD on one 4th cell. Has anyone done any home mods to enable the use of either the HUD or computer with the new coaxial cells?

If I can't find a suitable HUD that works with the new cells I guess my only option for this would be to go down the evolution route.

bgpartri · 31st March 2007, 21:53

Quote: (Originally Posted by laurawood)

I don't believe that the shearwater electronics fits the new co-axial connections installed with the new O2 cells. ....

The only way I would recommend using the Shearwater GF or the HUD on the Evolution is as a 4th cell monitor.

One of my customers came up with a cool idea. Put three coax connectors on the GF running through the Beanie adapter. Plug one of them in to a 4th cell and plug the other two with a dummy. It serves as an independant monitor. But then comes the cool part. If for some reason your Vision electronics dies in Timbuktu, plug the GF into the three cells and dive manually.

laurawood · 1st April 2007, 08:52

Is there no t piece type adapter available to enable an extra cable to be routed out from the new cells? Hence enabling the new cells to be used with the Shearwater HUD/ GF on all three sensors?

bgpartri · 1st April 2007, 17:18

I've never seen an Evolution connection except on the web, so I really don't know.

No one I dive with here has one.

Bruce

16th February 2007, 14:09	#31 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: Sheerwater vs VR3 for an EVO 4th cell? Quote: (Originally Posted by Mdemon) As for your DSV/BOV/HUD/4th cell, you need to complete the job and add the ADV to it. I'll look at the ADV as a feature as well, all one would need to do really is to have the BOV selector select exhaust valve "on" as well as loop "off" and vice versa and the same second stage could do both jobs. Let me do a little thought on that. Could be delivered Tuesday if you would like to post a suitable R&D/Production fee today, Let's say.... 10K sterling would motivate me to give up the weekend... shall I forward my bank details? Probably the way to do this would be to remote the electronics for the HUD with a cable up the inhale hose to the rig. My original system carried the HUD board and the battery under the DSV. With the second stage added I think that the form factor would get a little large for practical use. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
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16th February 2007, 15:44	#32 (permalink)
fireman rEvo combat swimmer Current Rebreather/s: rEvo Other CCR Other Rebreather/s: rEvo Other CCR Join Date: Nov 2006 Location: chicago Posts: 549	Re: Sheerwater vs VR3 for an EVO 4th cell? On a slightly relevant note, I saw the heads up mask at OWUW, very slick if somewhat expensive and perhaps over complicated. Hypothetically one could have all the info you wanted right there, and video games for deco... __________________ Heres to you Capt. Bill Never Forget, and stay safe everyone.
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16th February 2007, 18:04	#33 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,636	Re: Sheerwater vs VR3 for an EVO 4th cell? [quote=divetheworld;96726][quote=JonnyB;96724] Quote: (Originally Posted by divetheworld) Yup, the Shearwater will parallel with any unit that I have encountered because it has a very high internal resistance. It will not affect the APECS, and the APECS will not affect it. The software routine for calibration is matched for the Meg perfectly too. However............ As Bruce has just informed me there is no hole in the head to allow it. There are three holes, primary, secondary and HUD. You would have to do a little work to fit it like fitting your own gland to a user made hole. If you do decide to go this route, give Bruce a shout as he has plenty of experience his electrickery and Megs! Its worth getting advise from those that know, rather than those who have half the picture like me. Alternatively, the Shearwater meg conversion.......... Brent __________________ Attitude and self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe Last edited by divetheworld : 16th February 2007 at 18:06.
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25th February 2007, 16:24	#35 (permalink)
NickK New Member Current Rebreather/s: Evolution Other Rebreather/s: Evolution Join Date: Nov 2005 Location: Vancouver Island Posts: 90	Re: Sheerwater vs VR3 for an EVO 4th cell? Quote: (Originally Posted by Gill Envy) thank you everyone for your feedback on and off line. I'm veering toward the sheerwater at this point for the following reasons: -better match of deco with the vision -extremely efficient on batteries, which just seems like a sign of a well engineered system. -Build quality is impressive -auto on switch -HUD option -very intuitive screen layout -back light does not suck up the battery...can be left on a lot. -manufacturer is on the way to some of my favorite diving! -When i graduate to home building it can be my primary just kidding Hi Gill, Glad to see you are on right truck. The Shearwater computer the way to go. Why to waist money just to get PPO2 monitor if you can get "full meal deal" with Bruce's computer. PPO2 monitor, deco computer, also O2 solenoid controller for your next home built project. All in one, so far no reported problems with it, even display info close to Vision with matched GF algorithm (best match on the market IMO), and, according to my friends on Vancouver Island, Bruce is a fine gentleman and active diver, also in our neighbourhood. No hidden costs, secret pins or other PITA issues. What for fittings, personally I am using John's 4th cell adapter with future provision to use sensors in this configuration: 1-2-3 (as per factory default) for Vision and 1-4-3 for Shearwater. In about of week time will have an answer from one of our suppliers if they can supply me "V" adapter coax cable with SMB connectors make Shearwater connections to Vision's head O2 sensors easy, without any changes to original configuration. Let us know of your honest opinion on GF when you will start using it. Nick P.S. Moving to Vancouver Island - NA North West Mecca of Scuba Diving - in April and hope my ali boat will be built by September - October, as promised, so we can meet one day and go for some nice dives. Last edited by NickK : 25th February 2007 at 16:37.
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25th February 2007, 20:30	#36 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,347	Re: Sheerwater vs VR3 for an EVO 4th cell? Nick, thanks for your thoughts. Glad to hear you are moving to this neck of the woods. By all means look us up when you move out this way for some diving. I head up to BC several times a year. I have been contemplating hooking up the Shearwater GF the way you suggest, to two of the three vision cells. It's only natural to want to want to unleash the Shearwater. My reluctance in pursuing this approach is that it goes against the "isolationist" approach that Dave and others have convinced me has Merritt. Here is my current understanding: So the theory goes: if salt water ingress or some other short causes voltage irregularities, I don't want there to be a chance that the Shearwater will get polluted with errant current. This of course has to be balanced with the fact that with only a 4th cell connected to the GF, you have no voting logic for comparison. I'll take on the isolationist theory here, as well as I can (Dave et all chime in if I go astray), even though the jury is still somewhat out for many of us on weather or not cross over voltage contamination between cells to a back up system is really a possibility. The thinking goes: except in an emergency, you are not relying on the fourth cell, your're mostly relying on the primary. I think we can all agree, a single fourth cell has limited value and would only be relied entirely upon with significant caution and for short duration. In the isolationist paradigm of independent system cross check, the 4th cell would be there primarily to alert one to discrepancy... no shared batteries, no shared cells. In the instance of significant discrepancy, you'd do a flush and determine which cells/cells to believe while you end the dive. The only time you'd be relying on the 4th cell entirely is to the surface and end the dive... to the isolationist, the value of total independence outweighs the temporary hazard of bailing with the 4th cell...which you'd only do if you can verify proper functioning with a flush, and then of course there is always your OC BO bottle, when all else fails. The 4th cell would be verified for voltage limiting at the beginning of the dive with the rest of the cells and replaced if it goes AWOL before continuing to do the dive. It seems to me that the value of the 4th cell and totally isolated system is that you never really look at your electronics as a whole, but two separate systems to cross check. On the vision, if there is no HUD display blinking, no buzzers buzzing, and all three cells are pretty much in the same ball park, it's all too easy to assume everything is OK and not really be critical in one's thinking...to even become lulled into complacency. I'm hoping that having a totally isolated system will help instill critical thinking habits on top of the added benefits of redundancy. Isolation in redundancy is one of the elements in mCCR's, the KISS in particular, that i am convinced contributes to their zero fatality rate and merits integration in eCCR's. To date, I know of one common failure point in the vision electronics that can lead to a total system failure. If B1 fails suddenly (Wrong battery brand or I suppose a bad battery) the hand off mechanism to B2 can become disabled... if you want an example of that open up the battery compartment, hold the batteries in place while you power up...go through the start up and then allow the battery from B1 to drop out...screen goes blank, B2 does not take over. Voltage cross over to the back up controller through the o2 cells may turn out to be a second, yet seemingly a more obscure possibility. In any case I love the vision electronics, am happy it has one screen and some built in redundancy, but am also pretty convinced of the wisdom of a truly isolated, independently powered and independent o2 cell guided back up system regardless of what rebreather I could have chosen...and am happy to have that system be a completely different brand than the primary. g Quote: (Originally Posted by NickK) Hi Gill, Glad to see you are on right truck. The Shearwater computer the way to go. Why to waist money just to get PPO2 monitor if you can get "full meal deal" with Bruce's computer. PPO2 monitor, deco computer, also O2 solenoid controller for your next home built project. All in one, so far no reported problems with it, even display info close to Vision with matched GF algorithm (best match on the market IMO), and, according to my friends on Vancouver Island, Bruce is a fine gentleman and active diver, also in our neighbourhood. No hidden costs, secret pins or other PITA issues. What for fittings, personally I am using John's 4th cell adapter with future provision to use sensors in this configuration: 1-2-3 (as per factory default) for Vision and 1-4-3 for Shearwater. In about of week time will have an answer from one of our suppliers if they can supply me "V" adapter coax cable with SMB connectors make Shearwater connections to Vision's head O2 sensors easy, without any changes to original configuration. Let us know of your honest opinion on GF when you will start using it. Nick P.S. Moving to Vancouver Island - NA North West Mecca of Scuba Diving - in April and hope my ali boat will be built by September - October, as promised, so we can meet one day and go for some nice dives. __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°> Last edited by Gill Envy : 25th February 2007 at 20:44.
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31st March 2007, 11:32	#37 (permalink)
laurawood New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2007 Location: Dorset Posts: 8	Re: Sheerwater vs VR3 for an EVO 4th cell? I don't believe that the shearwater electronics fits the new co-axial connections installed with the new O2 cells. I have a new loom & the new cells on my inspo classic & wanted to install a HUD (as I lost both handsets on a dive recently due to battery bounce with no warning that no O2 was injecting). Bruce informed me that at present the only option would be to run the HUD on one 4th cell. Has anyone done any home mods to enable the use of either the HUD or computer with the new coaxial cells? If I can't find a suitable HUD that works with the new cells I guess my only option for this would be to go down the evolution route.
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31st March 2007, 21:53	#38 (permalink)
bgpartri CEO-Shearwater Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Titan Join Date: Apr 2005 Location: Vancouver, Canada Posts: 423	Re: Sheerwater vs VR3 for an EVO 4th cell? Quote: (Originally Posted by laurawood) I don't believe that the shearwater electronics fits the new co-axial connections installed with the new O2 cells. .... The only way I would recommend using the Shearwater GF or the HUD on the Evolution is as a 4th cell monitor. One of my customers came up with a cool idea. Put three coax connectors on the GF running through the Beanie adapter. Plug one of them in to a 4th cell and plug the other two with a dummy. It serves as an independant monitor. But then comes the cool part. If for some reason your Vision electronics dies in Timbuktu, plug the GF into the three cells and dive manually. __________________ http://www.shearwaterresearch.com Good judgment comes from experience. Experience comes from bad judgment.
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1st April 2007, 08:52	#39 (permalink)
laurawood New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2007 Location: Dorset Posts: 8	Re: Sheerwater vs VR3 for an EVO 4th cell? Is there no t piece type adapter available to enable an extra cable to be routed out from the new cells? Hence enabling the new cells to be used with the Shearwater HUD/ GF on all three sensors?
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1st April 2007, 17:18	#40 (permalink)
bgpartri CEO-Shearwater Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Titan Join Date: Apr 2005 Location: Vancouver, Canada Posts: 423	Re: Sheerwater vs VR3 for an EVO 4th cell? I've never seen an Evolution connection except on the web, so I really don't know. No one I dive with here has one. Bruce __________________ http://www.shearwaterresearch.com Good judgment comes from experience. Experience comes from bad judgment.
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