Argonaut workout

[Nemrod]

So, I decided to take the Argonaut for a spin. I first attempted on my Nordic Track but that was somewhat scary so I decided to mount the Argonaut and tank to my Centurion Prestige which winters on my trainer.





Now, I can, on a good day, still do a good 20 miles in an hour (maybe). Before the fractured leg I could make 25 in an hour (yeah, sure you could ). Not spectacular but okay for an almost 60 year old. So, I began with a full 63 cf tank and worked myself into my heart rate target zone before going to the Argonaut. I hammered hard and found it capable of providing more than enough air volume. However, exhaust is a limitation. I cannot get enough air through the system without having to exhale through my nose. But, I also ran a Scubapro 109, a RAM Phoenix, AL Titan XL, Conshelf XIV and NONE of them except for the Titan XL could hang any better than the Argonaut.

My speed was probably equal to, per my Cateye, to be 22 MPH, sustained for 5 minutes on the various regulators. This is very physically demanding and took me several days to do them all as each workout consumed about an hour from start to finish. I did each regulator the same. Only the Argonaut and the Titan XL had sufficient THROUGH PUT volume to sustain about 20 MPH, going to 22 MPH resulted in my having to exhaust through my nose and regulator.



The Argonaut has one of the lowest exhaust back pressures I have measured on my limited equipment (three Magnahelics with positive and negative scales). I am confident that the Argonaut will perform on par with any current regulator of any type for sport diving activities and depths and beyond.

Over the years, I have engaged in numerous, uh, discussions concerning the WOB. People often confuse cracking effort as being the most significant factor. I beg to disagree and I think physical studies have shown, exhaust back pressure to be the larger factor. In any case, I find it interesting that at my FULL OUT effort, none of the regulators I have at my disposal could flow enough air on the exhaust cycle to clear my lungs for the next inhalation.


http://s23.photobucket.com/user/JRWJR/m ... 3.mp4.html

Not conclusive, not the end all test, but best I can do without taking the fluid trainer to 100 feet. And yes, I was a little off balance on the bike because normally my knees come up into the area occupied by the butt of the tank. This caused me to choose a higher gear and a lower cadence than I would normally have. But, trust me, it felt real to me.

Nem

[swimjim]

Hey I'd settle for a repeat test in 60 fow! I've got a crappy Huffy you can use for the test! LOL.
I see we use the same Aero Bars!

Jim

[Nemrod]

Hey I'd settle for a repeat test in 60 fow! I've got a crappy Huffy you can use for the test! LOL.
I see we use the same Aero Bars!

Jim

Well, I am not putting my Centurion in salt water . I just rebuilt it two summers ago.

I bought that bike in the late 80s. I was scheduled to do a Bud Light Tri and my Pinerello came up lame and I needed a bike. A local shop loaned me the Centurion and it felt so good I bought it rather than give it back.

I do not really like aero bars but they do help on a triathlon since the old centurion is already challenged by the $5,000 dollars purpose built carbon fiber triathlon bikes. And, they cradle and aluminum 63 like they were made for it.



Nem

[Bryan]

When I asked you to test it while exercising I had no idea you would go to this extreme! I realize it's not exact science but it proves out what we have been saying about the regulator for a long time.
I'll bet Luis has seen this and is at home right now trying to figure out how to hook you and the bike up to his test bench.....I'm not entirely kidding either

I'm fortunate to have friends who enjoy being guinea pigs

Thanks for the great Christmas post!

[swimjim]

I've never heard of "Centurion" bikes, but she looked like a nice ride. Light and fast! Probably in the 18 lb range with my Klein. I've never liked the Aero bars myself as they make you ride on an important part of the anatomy. LOL. Hence the suggestion of a Huffy for the salt water test.
Personally I'm trying to motivate the local troops to do some diving below the ice sheet. It's not as easy as it used to be as we are all getting older and wiser. Ha

Jim

[luis]

I was talking to James recently about the breathing simulation test dummies they have at NEDU (Navy Experimental Diving Unit) in Panama City. He immediately said that he was not volunteering to have a pressure probe surgically implanted on the back of his throat.

The dummies measure the pressure associated to the sensation of WOB on the back of the throat near the top of the throat.


The Navy EDU and the ANSTI machines test diving breathing equipment at extreme realistic flow rates, 75 lpm (2.65 cfm) and 62.5 lpm (2.2 cfm), and a variety of depths (ranging to 198ft for regulators using air).

Well, I don’t have those facilities, therefore the best I can do is to do scaled simulations.

Without getting into all the technical background, let me just say that it is possible to take reasonable measurements using non-dimensional scaling numbers. In this case since I don’t have a pressure chamber to test at depth, what I did is increase the flow rates to match the same Reynolds number that the regulator would be working at depths. With flow rates of 15 cfm (and higher), the regulator is working as hard as it would at around 198 ft during very hard breathing/ working conditions (or about165 ft with extreme breathing conditions).

This is not as precise as doing actual depth simulations, but for that reason I used several well known regulators for comparison (side by side) testing, using all the exact same conditions. What I did is not only a depth simulation scaling study, but it was also a comparison study.

The highest inaccuracies doesn’t come from the scaling (for depth simulation), it comes not having equipment to simulate the actual breathing cycle. I am doing steady state flow rate capabilities of the regulator, not WOB. Therefore, it was very important to do the side by side comparison against well known regulators, used as bench mark.

I also did comparison studies with the metal versus the plastic can.

To obtain the flow rates I had to use a shop vacuum (James is in good shape… but I don’t think that he can’t suck that hard).



Results will follow later, but I can say that I am extremely pleased with the results.

Great job Nemrod!


BTW: at NEDU in the Ocean Simulation facility they had some stationary exercise machines (similar to stationary bicycles, etc.), that divers used in the wet chamber to do work simulation tests.


Here is my set up.



Here is the shop vac I used.

[Nemrod]

And something that I guess I knew but did not think about until talking to Luis is that an average flow rate is just that, an average. The peak value, at an instant, in an inhalation or exhalation, could be much higher. And this is what the ANSTI machine, if I understand, really gets at when they rate breathing performance. The Titan XL is rated at Superior which is the highest category. The Argonaut, in my opinion, is at least as good.

It was not the inhalation that was limiting me and causing me to "crash" or go anaerobic but the inability to purge my lungs and then take a full follow on breath. The exhaust effort was noticeable in both the Titan and the Argonaut, though much better than the others.

This is why I think one of the most noticeable differences in single hose second stage design over the years has been a steady increase in the exhaust valve size and attention to the exhaust manifold/plenum. The new SPG260, I think they upped the size yet again. I have not confirmed that but SP had already enlarged the exhaust valve in the G250 over the 109. There are other things that enter into single hose WOB, like case fault for example.

Along those lines, my 1966 Calypso J inhalation effort, just my feeling, is as good as my best Conshelf but the tiny little exhaust valve, like a 20mm-ish, and the lack of an exhaust plenum is a huge restriction on flow through put and seriously increases the WOB. And, the SP 109BA, yes, it is the little 25mm exhaust valve vs the 30mm (I think it is ) on the Conshelf XIV, Titan XL and the Argonaut, that holds the 109 back.

Anyways, it is good to discuss these things but the important thing to take away is that the Argonaut is performing on par or better than some very well respected regulators.

And, well, hmm, this could leave an opening, but, while I cannot out suck Luis' Shop Vac, all that swimming has given me, a brag or not, powerful diaphragm muscles, my peak or instantaneous value is probably pretty high. And it was this that I was trying to get a feel for with these tests, would the Argonaut satisfy my peak requirement which I am pretty sure, at my anaerobic threshold, exceeds any normal diver working at a normal effort even at 4 or 5 atmospheres. And it did , the exhalation was a surprise to me and I guess I knew that also, just did not think about it until I experienced the phenomena.

I have been tested back when I was seriously trying out in the triathlon sport back around 1984. I do not recall my VO2 max, but it is up there. I can suck some air, but not I am afraid like a Shop Vac.

Let me add something else, During inhalation, the diaphram muscle moves down and that column of air that extends over your head all the way to outer space and produces a force of 14.7 psi at sea level forces the air in. However, not the case upon exhalation, the diaphragm must actually provide an evacuating force to push the air out of the lungs. This is why exhalation is so sensitive to any back pressure and key to, IMO, reducing WOB.

And a last point, let me make it clear, the Argonaut has the lowest exhalation effort I have ever measured best I can remember with my test equipment.

Nem

[antique diver]

In a normal sort-of horizontal diving position the exhaust point will be higher in the water column than your lungs (at lower pressure than your lungs) when using a double hose reg. While diving that might make a noticeable assist in evacuating the slightly higher pressure in your lungs upon exhalation. At least it feels that way to me when using a DH reg.

[SurfLung]

- Hey Nemrod, your comment about having to exhaust out your nose rang a bell at the tip of my brain... Remember our discussion on swimming laps with a snorkel? I found the same thing when I am at about my maximum... The tendency to exhaust out my nose and mask is very strong and requires conscious effort to keep from doing it. I just thought the shut-off muscle was tired like the rest of me.
- Great test method by-the-way... And fun to read about and watch!

[Nemrod]

In a normal sort-of horizontal diving position the exhaust point will be higher in the water column than your lungs (at lower pressure than your lungs) when using a double hose reg. While diving that might make a noticeable assist in evacuating the slightly higher pressure in your lungs upon exhalation. At least it feels that way to me when using a DH reg.

I agree and surface simulations are always going to vary from the intended use in water. An advantage of double hose over the single hose.

- Hey Nemrod, your comment about having to exhaust out your nose rang a bell at the tip of my brain... Remember our discussion on swimming laps with a snorkel? I found the same thing when I am at about my maximum... The tendency to exhaust out my nose and mask is very strong and requires conscious effort to keep from doing it. I just thought the shut-off muscle was tired like the rest of me.
- Great test method by-the-way... And fun to read about and watch!

I did not have it on in the photos but as I pushed to 20 MPH I used a Speedo nose clip. It is a piece of wire that pinches the nose shut. I use them when I swim to prevent chlorine from going into my sinuses. I do sort of remember the discussion. . Here is the thing, on all of the other regulators except for the Titan XL and the Argonaut my maximum sustainable speed without exhausting through my nose and regulator and not crashing (going anaerobic) was about 16 MPH. With the Argonaut and the Titan XL I was able to sustain 20 MPH. Above 20 MPH, I went to 22 MPH, I went anaerobic and it was not sustainable.

My fluid trainer is designed to simulate road use, now does it exactly, no. But it is a good trainer and the results are relevant since all regs were tested on the same trainer with the same motor (me). On a bike (true of airplanes, anything) for a given flat plate frontal area, each time the speed is doubled, drag quadruples and so does the required energy to go that speed. So, a jump from 16 MPH to 20 MPH is a pretty good increase in motor output and to 22 MPH .

Antique Divers point is understood and in our snorkel discussion being slightly submerged, pressure at lungs being greater than at the ambient of the snorkel outlet/inlet you have that greater resistance working against inhalation but assisting exhalation, probably much like swimming horizontal with a double hose. The double hose regulator offsets that extra inhalation effort with a well designed and modulated Venturi effect. Luis did not just say, hmmm, that looks about right, he I am sure, calculated it . The Argonaut Venturi effect is powerful. And as you point out, when horizontal, the pressure differential between the mushroom exhaust and lungs can assist the exhalation effort.

This is why I am not concerned about the exhaust effort, despite it being better than the other regulators, once in the water the double hose design has that advantage. In the water, the Argonaut exhaust effort is, effortless and noticeably less than the DBEV equipped cans and noticeably less than a good single hose (when horizontal due to case fault). BGTW, the Tekna T2100 has a large exhaust valve, no hoses between it and the sea and no case fault. It has the lower effort I bet, I need to measure it.

Venturi effect, the ANSTI tests consider positive pressure on the inhalation cycle to be a negative if above positive .2 inches (I need to verify that again, I lost the report and cannot remember for sure). I have always liked a regulator that could be tuned to push air to me at depth. Going off on the Tekna, like many servo assisted regs, it would indeed push air at depth. Unfortunately, it also positively pushed air at 20 feet and would get a feedback effect producing stuttering. This was not due to Venturi but the servo assist. The Venturi effect of a double hose though behaves similar once the Venturi is established and therefore must be carefully designed (or luck) to be sufficient to help overcome the negative pressure differential between the center of the lungs and the diaphragm position but not so strong that it shoves air at the diver and blows air past the cage valves, over breathing, waisting air.

Well, I get to get going, long drive to New Orleans.

Nem

[luis]

With all these posts about regulator testing someone ask me if we where still in the testing and design fine tuning stage of the project. The short answer is not at all.

The mechanical parts and main body of the regulator were designed well over year ago and I did all the instrumented bench testing needed before we went to Cozumel in 2012.

Last summer I redesigned the can and had rapid prototype (3D printing) made for dimensional checking and testing. I did again a lot of bench testing and in the water testing. I did a lot of testing and diving with that prototype can.

After all that testing, I sent Bryan the can with final drawings to have the mold made.

In Cozumel 2013 Bryan showed up at the last minute with six brand new molded samples of the can and we swapped cans in the patio at the resort. We did a lot of diving with the sample Argonauts. We had about 10 Argonauts, several in metal cans and a couple with 3D printed prototype cans.

There have been no mechanical changes needed since the original design in early 2012. We did find some regulator were not adjusted according to my design, so I have added some indicator marks to make it easier to explain how to adjust the second stage volcano orifice. This was not a required change, but it makes it clear to the DIY/ tinkerer on what not to do. I will explain the details later.


So the question comes of why is it not on the shelves for sale already. Well, that has to do with the economics of production. Bryan is doing a Kickstarter program to get enough funds to do it right. If you haven’t read about it, you can see some information in this link.

http://vintagedoublehose.com/index.php? ... ort=normal


In the mean time, we are expanding the testing, not because it is required, but because we can.

We are also working on other possible future accessories, like hoses, mouthpieces, etc.

[Nemrod]

Yes indeed and the excellent performance above and below the surface is proof of the excellent design and standards.

Nem

[JES]

Nice work Nemrod and Luis!

[Nemrod]

I should have named this thread "Regulator Workout" and put it in the General Forums. It was not intended to be a validation of Argonaut performance. I was curious as to the elements of WOB and I just happened to have two Argonauts on hand to include in my play. Cracking effort, inhalation effort, exhaust effort. I think from reading so many discussions that people fixate upon cracking effort as being the most important of the three. My observations is that it is only important because it is easy to measure, other than that, it is actually the least important aspect. Inhalation effort in many if not nearly all regulators including the Argonaut (with it's powerful Venturi assist) actually show positive numbers during at least part of the inhalation cycle. So, to me, as long as volume is sufficient then inhalation is not the most limiting factor either. This is evidenced by the values being positive, therefore diver demand (volume) must be satisfied, otherwise the values would always be negative.

So, the remaining factor is exhaust effort. Our double hose regulators have an advantage here in that in typical swimming position the exhaust is above the center of the lungs, assisting the (chest cavity) diaphragm to evacuate the lungs. All of the regulators I used where tuned to my best ability, all satisfied inhalation demand and I found cracking effort not really a factor, what I did find instead is that the throughput, total volume of air moving through the system was limited by the exhaust back pressure.

The Argonaut was equal to the Titan XL in this regard but not better. BUT, in the water, the Argonaut, because of the reasons already mentioned, performs even better. Like all double hose regulators, exhaust effort in swimming position is assisted by it's position relative to the divers lungs. Advantage double hose. In actual use, in the water, the Argonaut is the lowest exhaust effort I have encountered and it is born out by my experience comparing to other regulators.

Single hose regs, due to case fault, usually have the exhaust valve slightly lower than the lung center, disadvantage single hose. I think this is why the SCUBA companies have steadily increased the size/area of the exhaust valves and reduced as much as possible the exhaust tees of their single hose second stages.

It appears, lol, that I have tweaked some 109 fans, sorry, it has a tiny exhaust valve, 25mm, and it has case fault. While it is still a fine regulator, I doubt seriously it would rate Superior on the ANSTI machine tests. And, it is not cracking effort, it is not inhalation effort that is it's limitation, it is the tiny exhaust valve compounded by case fault (not that 109 is worse here than most).

I would really like to get a G260 SP again. I used one briefly in the pool a few weeks back and it is clearly superior to the 109 and from my memory, the G250 and again, it is the exhaust effort, where the difference lies.

Nem