Mares Axis Octo freeflow
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Former FLL Now MSP Diver
Contributor
I've been experiencing the same problem with my daughter's 2nd and octopus. One or the other would slightly leak every few dives and we'd have to take it back to the LDS to be adjusted.
This past weekend it started again. We went to another shop to have it looked at that was next to the beach we were diving from. Though not a Mares shop, they took both regs and adjusted them, using gauges (UNLIKE the LDS who normally looked after them and would just crank something down inside the 2nd's) to set the IP in all three stages.
They said that Mares were known for having soft valve seats, and they don't always seal properly. This causes the first stage IP to creep up over successive uses, and the higher pressure would cause the the two second stages to leak.
They also made all the adjustments at no charge.
It's coming up on the yearly service for this reg, and even though they aren't an authorized shop I think I'll be taking it there to be done. So much more professional and knowledgable.
Hats off to Dixie Divers in Deerfield Beach, FL.
Marc
This past weekend it started again. We went to another shop to have it looked at that was next to the beach we were diving from. Though not a Mares shop, they took both regs and adjusted them, using gauges (UNLIKE the LDS who normally looked after them and would just crank something down inside the 2nd's) to set the IP in all three stages.
They said that Mares were known for having soft valve seats, and they don't always seal properly. This causes the first stage IP to creep up over successive uses, and the higher pressure would cause the the two second stages to leak.
They also made all the adjustments at no charge.
It's coming up on the yearly service for this reg, and even though they aren't an authorized shop I think I'll be taking it there to be done. So much more professional and knowledgable.
Hats off to Dixie Divers in Deerfield Beach, FL.
Marc
I've seen an Axis do the exact same thing that you are describing, basically it just takes a tech who will take the time to tune the regs out properly. One thing that may cause a problem is that some Mares regs use hex adjustment screws and not your standard slotted type (for which most shops have a tool to make adjustments while the set is under pressure.) This makes for a tech who has to pull the hoses off, make an adjustment, put the hose back on, test...hrm...pull the hoses off, make and adjustment, and on and on. That may be why you aren't getting you reg tuned well - it's just too labor intensive without the proper tools and a dozen other regs on the bench waiting to be serviced.
ScoobieDooo
Guest
Regulator Technicians correct me if I am wrong, but I believe the problem is that the Mares does not have adjustable orifices, so that creates a 2nd stage that isn't really adjustable for 'cracking pressure' due to design. The only way to stop this diemma is to 'detune' the demand lever so that its takes more demand lever travel to make the reg begin to flow. However, this makes inhalation effort higher. If I am correct, it has something to do with the fact that Mares wanted to make their 2nds have less working parts and be easier to service, albeit, the tendency to free flow.
My suggestion, buy an Apeks, Scubapro, Aqua Lung, Poseidon which sports an inherently better design.
PS I'm not flaming Mares, as I know for a fact that they are easy breathers (I used to own an Axis), however, this 'easy breathing' AND lower price makes for a reg that free flows constantly.
My suggestion, buy an Apeks, Scubapro, Aqua Lung, Poseidon which sports an inherently better design.
PS I'm not flaming Mares, as I know for a fact that they are easy breathers (I used to own an Axis), however, this 'easy breathing' AND lower price makes for a reg that free flows constantly.
After having my Mares Abyss & Axis Octo for about 2 years (and many dives) the Octo actually started to free flow in Bonaire on the very first day we were there.
When it was taken apart, it was discovered that the LP seat was no good on one side. So we flipped it over & I used it without incident the entire time. However, now that I'm home I'll have it replaced.
To my knowledge ALL regs are downstream regs so that they will be "fail safe". IOW, if they fail, they do so in the OPEN position, resulting in a free flow.
Upstream would mean they would fail CLOSED. Not a good idea, IMHO.
~SubMariner~
When it was taken apart, it was discovered that the LP seat was no good on one side. So we flipped it over & I used it without incident the entire time. However, now that I'm home I'll have it replaced.
To my knowledge ALL regs are downstream regs so that they will be "fail safe". IOW, if they fail, they do so in the OPEN position, resulting in a free flow.
Upstream would mean they would fail CLOSED. Not a good idea, IMHO.
~SubMariner~
ScoobieDooo
Guest
Taat2d,
Cracking pressure is the amount of force that a reg require to open the valve in the 2nd stage to let air flow into the reg - this is measurable on test machines for both inhalation force and exhalation force.
The amount of 'travel' or effort required to make this happen is whats measured and evaluated according to parameters the US Navy has established for their requirements.
At least, thats MY understanding of cracking pressure. If you go to Beauchats web site you can see a visual graph of what this measurement looks like for a reg when measured on test machines.
http://www.beuchatdiving.com/frame3.htm
To quote Beauchat, the following are measured:
1. Initial inhalation point. Effort necessary to induce air flow. Specifies diver breathing resistance.
2. Inhalation curve. The closer this curve is to horizontal axis, the easier the work of breathing, thus representing minimum effort required from the diver.
3. Venturi effect maintains a constant air flow, minimizing breathing effort.
4. Exhalation curve, the flatter the curve is, the easier the exhalation is for the diver.
5. The area between the inhalation and the exhalation curves represent the combined work of breathing effort during the breathing cycle.
Hope this helps...
Cracking pressure is the amount of force that a reg require to open the valve in the 2nd stage to let air flow into the reg - this is measurable on test machines for both inhalation force and exhalation force.
The amount of 'travel' or effort required to make this happen is whats measured and evaluated according to parameters the US Navy has established for their requirements.
At least, thats MY understanding of cracking pressure. If you go to Beauchats web site you can see a visual graph of what this measurement looks like for a reg when measured on test machines.
http://www.beuchatdiving.com/frame3.htm
To quote Beauchat, the following are measured:
1. Initial inhalation point. Effort necessary to induce air flow. Specifies diver breathing resistance.
2. Inhalation curve. The closer this curve is to horizontal axis, the easier the work of breathing, thus representing minimum effort required from the diver.
3. Venturi effect maintains a constant air flow, minimizing breathing effort.
4. Exhalation curve, the flatter the curve is, the easier the exhalation is for the diver.
5. The area between the inhalation and the exhalation curves represent the combined work of breathing effort during the breathing cycle.
Hope this helps...
I don't know if the solution has been posted yet, as there are a lot of replies. But a couple years ago, when they first came out, I was on a boat with a Mares rep, and I asked her about the problem. (I dealt with a lot of rental regs that freeflowed. )
The Solution/Problem
The Axis 2nd stage requires a different adjustment gauge than the previous Mares regulators, but many were shipped after being adjusted with the wrong gauge. This is easily adjusted with the correct adjustment gauge, or by simply backing off the adjustment nut inside the 2nd stage until the freeflow stops.
The Solution/Problem
The Axis 2nd stage requires a different adjustment gauge than the previous Mares regulators, but many were shipped after being adjusted with the wrong gauge. This is easily adjusted with the correct adjustment gauge, or by simply backing off the adjustment nut inside the 2nd stage until the freeflow stops.
ScoobieDooo
Guest
In other words, 'detuning' the reg...
chrpai
Contributor
Sorry for jumping in late, I just noticed this thread.
I have a Mares MR12 Axis rig. Both my 2nd stage and my octopus had issues where they would hiss. ( Freeflow is an overstatement. ) First it was one, then the other. Each time the LDS checked the Intermeddiate Pressure and it was fine. Then they went in and adjusted the cracking pressure and it was fine. They said all their rental regs did it also so it didn't seem like any suprise to them.
Well I since got tired of wasting 500psi on a dive when it would do that. So I figured out how to dissasemble my 2nd stages and do it myself. They go in through the side with a special tool to remove the plug and another special tool to reach in and grab the bolt. I go in through the front. My fingernail removes the "lock" pin and then unscrew the face plate. Remove a retaining ring and diagphram and all is exposed. A leathermen can easily get to the nut that controls the cracking pressure and give it ever the slightest adjustment.
Now I like my regulator just fine, this doesn't bother me. But for the person I saw post saying they put this on a bungie DIR style. I do hope someone trying to go for that kind of rig uses a more approriate regulator --- ie one with an external adjustment for cracking pressure.
Chris
I have a Mares MR12 Axis rig. Both my 2nd stage and my octopus had issues where they would hiss. ( Freeflow is an overstatement. ) First it was one, then the other. Each time the LDS checked the Intermeddiate Pressure and it was fine. Then they went in and adjusted the cracking pressure and it was fine. They said all their rental regs did it also so it didn't seem like any suprise to them.
Well I since got tired of wasting 500psi on a dive when it would do that. So I figured out how to dissasemble my 2nd stages and do it myself. They go in through the side with a special tool to remove the plug and another special tool to reach in and grab the bolt. I go in through the front. My fingernail removes the "lock" pin and then unscrew the face plate. Remove a retaining ring and diagphram and all is exposed. A leathermen can easily get to the nut that controls the cracking pressure and give it ever the slightest adjustment.
Now I like my regulator just fine, this doesn't bother me. But for the person I saw post saying they put this on a bungie DIR style. I do hope someone trying to go for that kind of rig uses a more approriate regulator --- ie one with an external adjustment for cracking pressure.
Chris
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