Project Argonaut, totally new, vintage style DH regulator

[Nemrod]

I am not much into my tank dragging behind me. As Luis mentions, the Argonaut has probably the most effective Venturi of any double hose regulator I have experienced. This combined with the super flexible diaphragms and HPR valve and the very low cracking effort these can be adjusted to, really goes a long way to making the Argonaut less sensitive to tank position.

I am a rebel here, just not much into the tank position thing, fore and aft anyways, close to my back and roughly centered between my shoulder blades, I call it good and go about my business. And the Argonaut allows me to go about that business better than ever. Thank you.

N

---------- Post added November 30th, 2014 at 12:07 PM ----------

Uh, just one thing, if y'all gonna do surgical implantations I think the Argonaut will have to come in a special surgical titanium version.

You know, twin hose diving is no longer vintage. I can be fully 21st Century and dive double hose, amazing. Can you imagine that people used to dive with those old fashioned twin hose things! The Argonaut is so sleek and modern in comparison. I am a man of the age, not a diving fossil.

John, have you heard of chaos theory and entropy? I think you may have some of it going on. If Sheldon took up SCUBA, well, you and he would have to work it out .

N

 

[John C. Ratliff]

Nemrod,

I have done a lot of experimenting with positioning of double hose regulators. Last summer the question came up about the Cousteau divers using a triple tank configuration with the double hose regulator on the outside tank, away from the diver's back. They were using Royal Mistrals, and this was on their dives on the Britannic shipwreck, in very deep water. The regulator positioning seemed all wrong, so I configured my doubles as independent doubles and dived them as depicted above. I found that the breathing effort did vary with the positioning, and if I dipped my right shoulder so that the Mistral was lower in the water column, it breathed better. I also put a double hose regulator on a Dacor Nautilus, which holds the regulator a bit high and about two inches further off my back than normal; again it breathed harder, but I could compensate by swimming along the bottom in about a 45 degree angle head-down.

The venturi does make a difference, and I'm sure that the Argonaut has a venturi which nearly breaths for the diver. I have several regulators that have that powerful a venturi and it is very helpful. But what we are talking about is cracking effort, and that is affected by the position of the regulator in relation to the center of the diver's lungs. Single hose divers experience this too, when even the best-performing single hose second stage is positioned about a foot or more above the center of the lungs when the diver is vertical and looks up at the surface; the diver can feel the inhalation effort difference. Again, this has nothing to do with the engineering, but with how the regulator is worn underwater.

If you'll look at my buddy diver Sid Macken using a Phoenix Aquamaster, you can see the "head" of water pressure developed by the regulator's position in relationship to the center of his lungs. It is actually above where a single hose regulator would be in the water column. My point is that by dropping the regulator down lower, especially with doubles, the advantages of the double hose regulator are maximized.

Concerning my being associated with Chaos Theory, I admit to it. This probably rubbed off from my USAF days, where in our rescue exercises we would say, "An luck would have it..." or "As fate would have it..." and say that something chaotic had happened we had to contend with. But Chaos Theory says that systems are sensitive to initial conditions, which is what I'm pointing out. Concerning Entropy, I've read about it, but will leave it to my two sons, Brian and Nathan, who are the engineers and mathematicians of the family (respectively). Though I do have a "gradual decline into disorder," my wife tries to keep me on an even keel.

John

PS, the photo of Sid was taken with a Nikonos II, 28 mm lens, and natural light.

 

[Luis H]

Regulator Position
We all agree that regulator position is very important to the cracking effort and breathing performance, but only the relative vertical position is what matters for pressure differential in the water column. Horizontal position is totally irrelevant. Therefore, if a diver’s tank was truly horizontal in the normal swimming position, the tank and regulator location on the divers back would make no difference.

The reality is (from many observation, etc.) that the most common swimming position (even for technical divers) includes a slight slope on the scuba cylinders. By observation and measuring pictures (of even the most stringent technical diver) I have seen a slope that rages from as low as 5 degrees to many as close to 15 degrees. In these observations, I am not counting the “bad form” from over-weighted divers that have to constantly kick in a highly sloped posture to keep from sinking to the bottom. I am only referring to divers with neutral buoyancy, but in a comfortable swimming position looking forward. (See picture at the bottom of the next post)

At a high average of 10 degree slope, moving the regulator 2 inches on the divers back towards his feet translates into a vertical displacement of 0.34 inches (this is just basic trigonometry). I picked 2 inches because that is the maximum range difference that I have measured between the height (of the valve outlet) from a single tank valve to a set of vintage double tank manifold. I took these measurements on different valves and manifolds using the top of the tank neck as the reference datum line.

So I agree that it makes a slight difference, but we can easily reach points of diminishing return.

As I mentioned the effect in water column pressure differential is only affected by the vertical location in the water column. Therefore, far more important than the position down the divers back is that the regulator needs to be touching the divers back. Of course, small diameter tank/ tanks help a lot with that. More in this subject later.

BTW John, those center outlet double manifolds are vintage and not readily available to the modern double hose diver. This thread is about a totally modern regulator with strong vintage roots and I would like to keep the thread relevant to diving with modern gear. Bringing up vintage knowledge and diving style is relevant information, but those manifolds are not modern and most modern divers may not going to be interested in setting up a small set of double. If you want to discus this further, could you please start a new thread. Thanks

I also found it interesting that you posted pictures of your double with two of the worst performing double hose of all time (The Dacor and the Trieste). Yes, I am aware that you have done a lot of modifications and work on them, but really...

I have regularly adjusted the cracking effort on an Argonaut to a very stable and very repeatable 0.1 to 0.2 inWC, but obviously I have to detune to about 0.5 to 0.6 inWC for actual diving (that is the radius of the exhaust valve). I have not come across a regulator to date that can be adjusted to that low of a cracking effort, with that precision, stability, reliability, and repeatability. Again, because of the diameter of the exhaust valve it is not practice to tune it to anything less than 0.5 inWC, because it will developed a small free flow in some diver position (when the top edge of the exhaust is higher than the center of the diaphragm).


The Argonaut designed to optimize performance by bringing the regulator closer to the divers back and lower in the water column.

When I started designing the Argonaut decided to start with a mostly clean sheet of paper (actually CAD drawing and 3D model). I say mostly, because I obviously have a strong influence of 43 years of experience working with a number of different regulator designs.

One of the early decisions that involved trade-offs was how much did I want the regulator to stick-out away from the tank. The more it sticks out the closer it get to the divers back therefore better performance, but more chances of interference with some existing back-plates, backpacks, and BC’s.

I didn't have to think about it too long to decide that I wanted a double hose regulator that performed the best possible even if it wasn't compatible with some BC's in the market. I designed the regulator for performance, not for a mass market.

As a mater of fact, Bryan had some resistance to selling the regulator with a DIN adapter, because the adapter made the regulator stick out further from the tank, it did not look good and makes it more susceptible to damage if dropped. At first I agreed until I saw that a number of the DIN valves were mounted on very large fat tanks. In that situation the DIN fitting has the advantage of bringing the regulator close to the divers back (actually touching) where it belongs.

The Phoenix experience

Almost 10 years ago when I designed the Phoenix I was not very happy with the space/ length that the Phoenix needed to be, in order to have all the ports and meet all the other design limitations. It was like most things a very calculated compromise between all the requirements.

During the first redesign I was able to shorten it by 0.1 inches, but it was still relatively long.

The flip side is that it brought it close to the divers back and it could be positioned to perform great with the proper back-plate.

The experience with the Phoenix pointed to the need for a double hose specific back-plate to enhance performance, but that it could work with modern gear.

The back-plate

Almost 4 years ago, I decided that we needed a new simple back-plate made specifically for a double hose regulator. I liked the concept of the US Divers "Dog Bone" backpack, but I wanted something simpler and easier to make. I also had a simple Seacraft back-plate that was simple, but wasn't going to work with modern BC bladders and used large metal hose clamps to attach to a tank.

I decided to make my own design similar to the Seacraft in that it uses a simple flat plate, but I had to modify just about all the dimensions to fit the modern needs (BC wings, modern tank bands, etc.).

The new backplate has two set of slots to accommodate most BC wings available in the market. I designed it to use modern tank bands and the same 2 inch webbing used by all modern back-plates. The original Seacraft backplate also used two inch webbing, but I changed the method of attachment and the actual location of attachments to provide a more comfortable location (for lower backplate placement).

I also used the crossed shoulder straps to add lateral stability (so that it holds the top of the tank and regulator in the correct place). That concept was also used by the Seacraft design, but I first became familiar with the concept from its used in mountaineering and alpine backpacks. It is also common in a number of modern backplates.

The backplate is only 1/8 inch thick and it allows the regulator to stick through it and touch the divers back. If properly adjusted it will place the regulator touching the back of a diver between the shoulder blades (or lower if so desired). Just as important is that with the proper well adjusted harness, it will hold the regulator in place even with an inflated BC wing attached to it. A crotch strap is important and a sternum strap can be very beneficial to hold the kit in place.

My personal backplate is adjusted to make it very comfortable and it hold the regulator touching my back in what I consider to be a perfect location. I often feel the bubbles rolling down my back when I am swimming down. I can move lower or higher, anywhere on my back that I care to place it, but I have adjusted it to where I like it.

I sometimes say that of all the double hose regulator performance improvements I have designed, the backplate can be considered one of the most significant because of the position it places the regulator.

We travel a lot on dive trips and the backplate works great with the typical rental aluminum 80 found in most dive destinations.

IMHO, the combination of the Argonaut and the backplate (with a small wing) makes an ideal modern double hose dive kit with very strong vintage roots, but with the modern advantages: a good performing (well balanced) BC, a pressure gauge attachment (or computer transmitter), air sharing octopus, and most important a great performing regulator.


Regulator position and center of pressure sensation

BTW, the pressure differential that is most critical to diver comfort is not from the regulator to the center of the diver’s lungs, but from the regulator to the center of pressure sensor center on the diver. The location where we feel pressure (according to several physicians and the researchers at NEDU) is not in the lungs but around the back of our throat, toward the top of the throat. This is the reason why in a swimmers position with your head tilted forward (to look forward), the center of pressure sensation can be perfectly level with a well position double hose regulator.

John, I realize that you are going to want to argue this point, but if you what to argue, you need to take it to NEDU and other physicians I have talked to. I am just passing the information I got when I was there. It is not just an opinion that I formed or anything like that. If you want to start a new thread on the subject, please go ahead, lets try to keep this thread related to the Argonaut.


BTW, I dove with Sid in the Tacoma, Washington area a few months ago. Super nice guy. It was my first time diving in Puget Sound. It was some great dives.

Here is a picture of Sid. Yes, he should lower that tank.





---------- Post added December 6th, 2014 at 01:04 AM ----------




Talking about the Argonaut (getting the thread back in track)

I noticed that the regulator that Couv is trying in this picture (with a DSV type mouthpiece) is my original Argonaut, one of the original four.
I wanted him to try/test the mouthpiece.
This is in Cozumel, November 2014.

That same regulator was in Cozumel in 2012 and 2013.

It was under the ice in March of 2013

It was chromed in April of 2013

It was in Roatan, Honduras, in May of 2013:

It got new cans in November of 2013 in Cozumel:

It was in Bonaire in May of 2014:

In September of 2014 it did 46 dives in the Philippines:






Notice in this picture in the Philippines that in my normal swimming position my tank slope is about 8 degrees.
That regulator is touching my back and at 8 degree slope it will only move about 1/8" vertically for every inch that it moves down my back.






Between all this dives trips it has also done a lot of dives in the cold temperatures of Maine (and a few other cold water dives in Tacoma, Washington):





I am using the same regulator in all the pictures (some of the pictures show different hose loop).
In all this dives the regulator was only serviced once when I took it apart in March of 2013 to have it chromed. Since then it has been operating perfectly and I have no intention on servicing it for several more years.

 

[halocline]

Regulator position and center of pressure sensation

BTW, the pressure differential that is most critical to diver comfort is not from the regulator to the center of the diver’s lungs, but from the regulator to the center of pressure sensor center on the diver. The location where we feel pressure (according to several physicians and the researchers at NEDU) is not in the lungs but around the back of our throat, toward the top of the throat.

Yay......

Quite a post, Luis.

 

[reefrat]

I have no intention of hijacking this thread and if any moderator would like to move it- please do so! However it does relate to the subject matter and the people most knowledgeable to comment are already engaged in this thread- so here goes:
I have owned and dove a few RAM's over the years and intend to purchase one of the next batch of Krakens, which are the result of an absolutely outstanding effort on the part of all involved. My primary interest in in getting a little closer to marine life for video without using a rebreather and over the last few months I have been thinking quite a bit about what exactly I would like to see in a double hose reg.
The Kraken is definitely the best option out there but there are just 3 potential design mods to the general double hose design that I would like to throw out there for comment:

1. Is it possible to position the yoke (or DIN) fitting off-center near the top of the can with an internal gas channel to the demand valve, as opposed to the usual central position of the yoke? This would allow the tank to be positioned in a more typically modern position with the can still located low and central to shoulders.
2. Could the upper half of the exhalation side of the can be perforated with a large number of very small exhaust holes (around the upper outer edge) instead of the usual few large ones in order to break up the exhaust into a cloud of bubbles? This diffuser effect would presumably make the exhaust bubbles quieter and the lower half of the exhaust can could have the usual larger holes to vent gas in the event that the diver was breathing hard enough to exceed the capacity of the upper exhaust diffuser.
3. A mouthpiece that allows the use of preferential mouthpieces (comfobite, seacure etc) would complete the picture for me!

Cheers RR

 

[Luis H]

The Kraken is definitely the best option out there but there are just 3 potential design mods to the general double hose design that I would like to throw out there for comment:

1. Is it possible to position the yoke (or DIN) fitting off-center near the top of the can with an internal gas channel to the demand valve, as opposed to the usual central position of the yoke? This would allow the tank to be positioned in a more typically modern position with the can still located low and central to shoulders.
2. Could the upper half of the exhalation side of the can be perforated with a large number of very small exhaust holes (around the upper outer edge) instead of the usual few large ones in order to break up the exhaust into a cloud of bubbles? This diffuser effect would presumably make the exhaust bubbles quieter and the lower half of the exhaust can could have the usual larger holes to vent gas in the event that the diver was breathing hard enough to exceed the capacity of the upper exhaust diffuser.
3. A mouthpiece that allows the use of preferential mouthpieces (comfobite, seacure etc) would complete the picture for me!

Cheers RR

Those are good questions about the Argonaut potential.

Question 1: It is possible to design a totally different regulator with the geometry you suggest, but like with everything, there are always trade offs. The geometry you suggest will cause interference with most BC bladders and many tank valves.

If you look at the Argonaut case, I actually cut away from the lower back of the case all the possible volume to provide more space for a wing type BC bladders. The same is true about the reason I designed the can with a tapper front and back.

We also go back to my previous statement about "diminishing return" to the design investment. What I mean is that the gains can become very small compared to the trade offs.

If you go back to my previous post, you will notice that I was trying to point out that moving the regulator up-or-down in the same axis as the tank doesn't bring as much benefit as moving away from the center-line of the tank (and tank valve). That is what makes it touch your back. Again, think about the swimming position, when the axis of the tank becomes close to horizontal.

I did a lot of design trade-offs analysis during the early stages of the design. I paid a lot of attention to the demand valve position.

In many ways some may say that the Argonaut is just a refinement of the Royal Aqua Master, and I will not disagree that it takes a lot of elements from it. But if you look at the Mentor, you could say the same thing. There are a lot of detail differences between the three regulators, but the basic geometry builds on a proven design that works with our basic dive gear configuration we have.


Question 2: I have been experimenting with different way of creating an exhaust diffuser. The plan is to make it an optional add on, but it is imperative for it to have enough flow area to not restrict the exhaust resistance.

It also needs to separate the bubbles enough so the don't just join again just outside the surface. Some of the geometries I have tested seem promising, but it is to early to tell.

The use of some screens, just allowed the bubbles to join again just outside/ above the screen.

This is on my to do list of optional equipment, but it is relatively low in the priority list.


Question 3: This item is has the highest priority in my to-do list. Three of the different mouthpieces that I took to Cozumel in November had standard replaceable mouthpiece bites (normally used on single hose regulator). One of them was also an of-the-shelf rebreather DSV type mouthpiece.

I have a very good idea of how I want my mouthpiece unit to look and I have some of the drawings and model started, but I was taking some data and making observations about some of the trade-offs.

Again, like everything in life, there will be trade-offs.

I hope that I have answered your questions. Just stay tuned and you will see more developments on question 2 and 3. The real good thing is that they will items that will be backwards compatible.



One more comment about "backward compatible": If you notice, whenever possible I try to make my designs compatible with existing hardware.

For example, the can on the Argonaut can be replaced with a vintage metal can. The new can performs better (in many aspects), but the metal can works fine. I don't allow the backwards compatibility dictate or limit my design, but if I can accommodate it, it has a lot of advantages to have commonality.


Thanks for the questions.


---------- Post added December 6th, 2014 at 09:20 PM ----------

I have owned and dove a few RAM's over the years and intend to purchase one of the next batch of Krakens, which are the result of an absolutely outstanding effort on the part of all involved.

Thanks for the comments. The development has been a group effort, and it is not really over... There will always be some room for improvements or specialized options.

What most people don't realize is that for me this is purely a hobby. But as most hobbies, it is also passion. I have no financial affiliation with the production of the Argonaut (no gain or loss). I don't even own a production Argonaut, but I do have several prototypes (almost production quality).

The big benefit to me is that I get to own and dive a regulator and backplate kit that I specifically designed to meet or exceed the characteristics that I felt were most important.

My primary interest in in getting a little closer to marine life for video without using a rebreather and over the last few months I have been thinking quite a bit about what exactly I would like to see in a double hose reg.

You are the type of individual that I had in mind when designing the Argonaut. I like to get close to marine life without disturbing it. I do a little photography and some video also, but I mostly observe.

 

[herman]

Thanks for the comments. The development has been a group effort, and it is not really over... There will always be some room for improvements or specialized options.

What most people don't realize is that for me this is purely a hobby. But as most hobbies, it is also passion. I have no financial affiliation with the production of the Argonaut (no gain or loss). I don't even own a production Argonaut, but I do have several prototypes (almost production quality).

The big benefit to me is that I get to own and dive a regulator and backplate kit that I specifically designed to meet or exceed the characteristics that I felt were most important.

You are the type of individual that I had in mind when designing the Argonaut. I like to get close to marine life without disturbing it. I do a little photography and some video also, but I mostly observe.

The same goes for me, I have a lot of time invested in the Argonaut and dive one of the prototypes, many of the parts in mine (and most of the prototypes) were made in my shop off Luis's drawings but I have no financial part in the regulator. The experience of being on the front line of it's development and seeing it go from drawings, to a working prototype to an actual product will no doubt be a highlight of my diving life.

 

[John C. Ratliff]

Luis,

First, thank you for the detailed response to my post. My idea was to get people thinking about that regulator positioning, and I used what was available to me in photos (those are ones I've taken that illustrate some of my adventures with regulators). The Dacor is actually on R-4 body with a Dial-a-Breath cover, and after I worked with it a lot, became a regulator I could dive in open water (not really good, but okay). The Trieste II is highly modified, and is a very good performing regulator. But I used these photos simply because they were already taken. And, I agreed about the regulator positioning shown in previous Argonaut photos.

Concerning the center of the lungs verses the back of the throat, I have for years been using the very early work of Bill Barada (Barada, Bill, Let's Go Diving, U.S. Divers Company, Santa Anna, CA, 1962, pages 28-29; see that diagram below) for that. While I am very interested in the physiology, I have seen no references to the back of the throat being the throat. I'll look through the research and see whether I can independently confirm that finding. I do note that, in a completely horizontal position, the back of the throat and the center of the lungs, according to Bill Barada's Diagrams, are in the same location. I agree with you about the degree off the horizontal; we really are not in much disagreement here.

By the way, I've recently looked at the interior routing of my "vintage" valves, which I bought new--especially the Sherwood twin post that I see you are also using (maybe that says something about me being vintage, right Nemrod ). The Sherwood twin post twin tank valve, unlike the USD center post twin tank valve, seems to almost act like a restrictor orifice at very low tank pressure, as the air is routed from the center position up about 3/4 inch (USD routes it down from the seat to the outlet about 3/4 inch) to the seat, goes by the seat then down, making a 180 degree turn, than out to the regulator after traversing about one and 3/4 inches in the small-diameter tube. The seat of this valve only opens about two turns (a little over 1/8 inch), which seems to also restrict the air flow. This may, especially at low tank pressures, cause the Argonaut to not perform to its potential. What this means is that your use of the single tank with a modern valve with the special backplate for positioning may actually improve air flow through the Argonaut when compared to the same regulator in the same position but on a Sherwood double tank manifold (vintage), especially at low tank pressures.

By the way, the best argument for an underwater naturalist or photographer to get a good double hose regulator, such as the Argonaut, rather than a rebreather is found on this thread concerning a rebreather accident that recently occurred.

SeaRat

 

[John C. Ratliff]

One other question, Luis, is where did you get those beautiful yellow Jet Fins?

John

 

[Tug]

One other question, Luis, is where did you get those beautiful yellow Jet Fins?

John

Scubapro came out with colored jets last year. Some shops might still have them. I believe diveseekers.com has them still


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---------- Post added December 9th, 2014 at 02:43 AM ----------

http://www.diveseekers.com/ScubaPro_Jet_Fins_Yellow_p/sp-jetfin-yellow.htm



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