AMF VOIT Swimaster Titan II MR12

[Greg Barlow]

The late Jon Hardy of ScubaLab and I tried to come up with a way of attaching a double hose model to the ANSTI breathing simulator. It is designed to use "mouthpieces" that replace the standard ones used on single hose regs. It would have taken some engineering work and the mag didn't want to invest the money for a one-time shot.

I'm not certain if the companies that manufacture rebreathers have ever had the machines adapted for their use.

One of the reasons why Poseidon didn't offer some of their models for testing is that they relied upon positive pressure breathing. This is where the reg delivers more gas than what is desired. Some divers like the whoosh effect, but the majority don't care for the unnatural feel. The new Xstream reg doesn't rely on positive pressure and is reported to be a great breather.

A reg that has a cracking pressure under 1.0" is usually unstable at the surface and is very prone to free flows. I can usually set a Mares reg at 1.25" and have it perform wonderfully. Regs with an adjustable second stage for breathing effort are merely adapting the spring tension on the poppet valve to suit the needs of the diver. Most of these models should be set to actually free flow when turned all the way out. They should also be stored in this fashion as it adds to the longevity of the second stage seat.

Greg

 

[John C. Ratliff]

Greg,

It would be fairly easy to hoop up a double hose regulator to your machine with a Hope-Page Mouthpiece. It uses the same opening as standard single hose units use today. This is somewhat of a collector's item, but it could be done. It would adversely affect the performance, but at least it could be tested. I would recommend that the intake non-return be removed for the test, to better simulate the USD hose system. The Hope-Page Mouthpiece was used for a while on the U.S. Divers DA Aqualung regulator, before they came out with the Klear-Easy mouthpiece/hose system. It was also used on the Healthways Scuba regulators when they originally came out.

Concerning the breathing characteristics you describe, I mostly agree with you. Where we part is with the ScubaPro A.I.R. I regulator, which I still think out-performs most (if not all) of today's regulators. It has an extra-large exhalation valve (the regulator diaphragm, to be exact), and its breathing characteristics are outstanding. I've enclosed the chart ScubaPro put out on it from tests done in 1979.\

Compare these results with those published at the following websites, for today's regulators:

http://www.zeagle.com/reg2001_design.htm

http://www.zeagle.com/test_links.htm

http://www.beuchatdiving.com/regulators1.htm

http://www.atomicaquatics.com/reviews/a9708_2.html

ew1usnr

The older USD and AMF Voit double hose regulators have very easy exhalations, and pretty good inhalation resistance. I don't currently have a water manometer, and will need to make it again. Some years ago I gave mine to the University of Oregon Marine Lab at Winchester Bay, when I was doing some work for them.

I believe, based on earlier tests, that my Snark III has a breaking resistance of less than 1 inch of water. I seem to remember testing a USD Jet Air (plastic body, maroon color--beautiful reg), at about 1/2 inch of water, and with a very dynamic venturi. My AMF Voit Trieste II probably has a breaking resistance of less than an inch and a half of water. I'll give better readings later this week when I again build a water manometer (thanks for spuring me on )

SeaRat

 

[Greg Barlow]

John,

I will forward the idea for utilizing the Hope-Page mouthpiece for the ANSTI machine. The simulator scores for the regs are quite interesting for divers to ponder. I am a bit puzzled as to why Zeagle varied their inlet pressure. This is not standard protocol for testing.

Regs are fascinating, and I belive they are about as good as what is mechanically feasible.

Greg

 

[John C. Ratliff]

I have made a water monometer, and tested two of my double hose regs on it, the Snark III and the Trieste II. The setup is not the greatest, but here's the preliminary results:

Snark III cracking pressure: 1 cm or 0.4 inches of water.
Snark III max resistance: 4 cm or 1.6 inches of water.

Trieste II cracking pressure: 2 cm or 0.7 inches of water.
Trieste II max risistance: 4 cm or 1.6 inches of water.

Please note that these are highly modified regulators, and that these were out-of-wate tests using pretty primative equipment.

The Snark III has a Hope-Page mouthpiece, with the intake non-return valve removed. It also has an extra baffle in the regulator, which keeps the venturi pointed down the inhalation hose. The older Snark III regulators have five holes, with only one pointed directly down the regulator's inhalation hose. The other four are pointed in that general direction, but the outer two actually push up on the LP diaphragm. This tends to counter-act the venturi effect. Because of its sensitivity, this regulator leaks a bit when in the completely verticle position. That is because the exhaust is a mushroom valve in the outer cover of the case, and is larger than a centimeter from the center of the diaphragm.

The Trieste II has also been modified, with a hand-made LP diaphragm, one plugged hole in the LP nozzle, and a baffle in the mouthpiece to keep its venturi from cycling through the exhaust hose and out into open water. I could probably improve the performance a bit more by removing the silicone mushroom non-return valve in the mouthpiece's inhalation side.

With the Trieste II regulator, I can initiate a breath, remove my mouth, and the regulator will continue to flow when out of the water. That pretty good for any regulator.

I will test others, including my DA Aquamaster, over the weekend.

SeaRat

 

[Greg Barlow]

John,

Let's hear your report! Long live the vintage divers!

Greg

 

[scubafanatic]

Hi ew1usnr,

....that sure is a nice photo of your Trieste/Odin 'combo'! Everytime I see your 'interesting' inventions/adaptations of vintage gear it gives me ideas of cool stuff I need to try out with my vintage regs.

(I've got 3 Trieste II's--including 1 NIB--but all in great shape, as well as a mid-1990's Nemrod Snark III --in mint condition as well ,all with 'modern' multiple HP and LP ports!)


Karl

 

[John C. Ratliff]

I just tested your more regulators. Here's the results (again at the surface, and at ~1500 psi):

DA Aquamaster

Breaking: 2 cm (0.8 inches) of water
Max: 4 cm (1.6 inches) of water

USD DX Single Stage (the first USD single stage regulator)

Breaking: 5 cm (2 inches) of water
Max: 7 cm (2.8 inches) of water

USD Calypso IV

Breaking: 2 cm (0.8 inches) of water
Max: 3 cm (1.2 inches) of water

Sherwood Blizzard (without vanes), early 1980s

Breaking: 1 cm (0.4 inches) of water
Max: 5 cm (2 inches) of water

I think this shows that the older regulators are pretty good. While I cannot evaluate them on the basis of the sophisticated breathing machines, I can say that these are pretty good regulators.

One point; the above data was at 1500 psi. I don't have any low tanks right now, and so cannot evaluate the USD DX at low tank pressure. In a post above, I stated that I had evaluated a USD Jet Air (DW, plastic) regulator at less than half an inch of water pressure. That was at a low tank pressure, probably below 500 psi. The single stage, upstream regulators (USD Mistral, DW, DX; Healthways Scuba and Scuba Delux) all breathed a bit harder at high tank pressures. But you knew you were getting low on air when they breathed like a dream.

The DA Aquamaster was set to almost leak at <500 psi. It therefore was a but harder breathing at 1500 psi than it would be at 500 psi. So I would expect the performance of the DA Aquamaster to improve at the 500 psi range of tank pressures.

One of my dreams was to take a Mistral, modify a tank valve to accept a LP hose from a second stage, and attach the mistral to a second stage that reduced the interstage pressure approximately 135 psi. This would allow me to take a twin tank setup, invert the tanks, and place the regulator on a line from the first stage, place the regulator in the exact anatomically correct place on the back, have the valves accessable (DIR, are you guys reading this?), and even passible capturing the exhaust for inflating a BC. It would also give both LP and HP ports for a SPG, octopus, etc. I haven't yet been able to act on this (I thought about it about 20 years ago), but I'm getting in a better position to do it now.

SeaRat

 

[ew1usnr]

scubafanatic once bubbled...
....that sure is a nice photo of your Trieste/Odin 'combo'!

I saw that Jetstream on ebay for $40 as a "buy it now" and couldn't resist. It works great as an octopus on the Trieste.

I met some friends and did some diving this weekend. My circa 1972 Healthways Sonic worked great. The low air warning sounded just like an alarm clock. My modified 50-Fathom was great. I took my Trieste to 115 and had no complaints. Maybe it was the narcosis, but it seemed to breathe better the deeper I went. I also tried my brother's ancient metal-body, metric-fitting Poseidon Cyklon 300. It breathed teriffic. At about 90-feet I could feel the metal 2nd stage get cold with each breath. It was great.

A friend brought his compressor and we were filling our tanks on-site with a special multi-gas breathing mix (see attached). From left to right is a Dacor R-4, a DA Navy Approved, a Voit 50-Fathom, and a Voit Trieste.

 

[John C. Ratliff]

ew1usnr,

This is the mouthpieces baffle I took out of a Healthways Scuba Delux regulator mouthpiece, and put it into my AMF Voit Mouthpiece for my AMF Trieste II regulator with modifications to the venturi. This is what makes the venturi work, without bypassing the diver and blowing through the regulator. It should be exactly in the center of the mouthpiece, verticle to the plane of the mouthpiece and at exact right angles to the incoming air. Good luck,

SeaRat

 

[Bob3]

My darn ebay sniping software is on the blink, I just missed a MR12, it sold for $13.