Buzz
Senior Diver
Posts: 64
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Post by Buzz on Nov 29, 2005 8:00:52 GMT -8
Sea Krakken and I have been brainstorming a project to work on together for prototyping a modern double hose reg that would contain all the features that would make it the best double hose ever built. Our guidelines are very simple. If we are unincumbered by all the company politics and beancounters that have produced a double hose like the New Mistral.....then we should be free to design in all the things that Double Hose lovers would want to have in a new reg. If done right, we could possibly win over lots of new converts. Our first thoughts centered around asking the members of this board to give us advice and councel. Where else could we find such vast expanses of knowledge and expertise? Our intention is to go thru the design process one step at a time and incorporate all the features that have won their way onto the design thru proper discussion and debate. We will then model the regulator using SolidWorks design software and post the pictures of the model(s) to this board as we go along. When we have a completed design, we will cut metal and build a prototype. We would like to begin at the most logical starting place ........the first stage (to include the yoke)!! We would like to know what type of first stage that everyone considers to be the best....balanced, unbalanced, diaphram, piston, etc,etc...... (this can be either double or single hose) Any particular brand/model that has won anyone's heart???....maybe just a particular configuration...or a particular part like a seal or...... ? We would appreciate everyone's participation and contribution to this project. Thanx in Advance, Buzz
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Post by VintageDiverMN on Nov 29, 2005 8:20:06 GMT -8
Your wasting your time. I would never give up my vintage Mistral, it's the perfect regulator, easy breathing and easy to maintain. But it's your time, have fun.
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Post by RMannix on Nov 29, 2005 8:48:43 GMT -8
I'd stick with Conshelf guts. Parts readily available and machining the nozzle or cavity should be relatively simple. Recently overhauled a Mares MR12 DFC and while cosmetically slightly different, the parts look interchangeable with the conshelf. Much longer pin though.
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Post by nemrod on Nov 29, 2005 11:21:36 GMT -8
You should get together with Luis as well.
-------------------------------------------------------------------------------- "Your wasting your time. I would never give up my vintage Mistral, it's the perfect regulator, easy breathing and easy to maintain. But it's your time, have fun. "
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LOL--yeah---but at the rate collectors are pushing prices it won't be many years before they will cost a ton of money and last I checked there are virtually no parts available for the Mistral such as the seat and when Gomez offered to have his machinest make some there were very few responses. So, just how comminted are people to the old stuff when and if something truely new but vintage in character shows up? Something you can actually use at a resort, dive charter etc without being banned.
I think you have a great plan---please proceed. I like the idea of solid modeling, we have that capability in my work place but if I slipped a program in and a regualtor popped out I don't think they would be very happy!!
The Conshelf is a great desgn but dated, if your going to start fresh unless your trying to captilize on existing parts I think it would be better to do something else.
Obviously, it must be vintage like in looks and must use the standard vintage type hoses and it must have multiple ports for LP and HP. It would not hurt if it were slightly smaller in size than a the RAM, perhaps more like the Trieste. I have yammered about what I want before but I kinda like piston first stages but have nothing agaisnt the diaphram design. I would like a servo operated second stage based on the Tekna design. This would allow the main sense diaphram to be smaller than the actual can diameter allowing plenty of room for two large mushroom valves to be INSIDE the can for exhaust instead of those stupid duckbills. All rubber parts need to be silicone and all metal parts need to stainless. Why a servo second stage? they can be very small and the cracking effort is very small and large flow rates can be had for little effort. Just consider that even if the can appears vintage in size or slightly smaller don't get locked into the thought that the diaphram must entirely fill the can. What if the can were the size of a standard USD can but the sense diaphram were half the diameter and offset to the side allowing room for exhaust valves and the mechanicals of the servo second stage. The new Mistral is a joke, balloon sized hoses, quacky design, parts bin engineering. Something new but at the same time having the "correct" look that can sustain real diving in the real ocean and not a quarry pit where one must have a BC, must have an alternate air source, must operate an spg, may need a dry suit etc must have something other than a rigged up old Mistral and even while it is possible to do all that with the RAM it requires a plethora of connections and looping hoses. Not optimum.
Whatever it is it must breath on par with any modern regulartor to win over new converts and justify high costs.
People laugh at my Teknas but here is what the manual says---"there are no parts within the second stage that will degrade significantly with time"---yep-----for the most part the statement is true. Of course, since we are still diving double hose regs that are 40 years old with the original parts in them I suppose that can be said of them as well--therefore---the bench mark is very high for a new design---vintage looks, top notch performance---will support all needed connections and devices----and absolutely reliable.
James
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Post by Gomez' echo on Nov 29, 2005 12:12:11 GMT -8
Absolutely marvelous idea. The concept of reproduction is the way to go. Obviously there are still many originals available, but as we have all seen, the prices go up and up. Once a collector with the $$$ gets the bug, he buys up all of the "good" ones and allows us "little guys" the scraps. So reproduction is a great solution. I would like to see the reg as original looking as possible. However, it must include a lp port or two and a hp port. Silicon hoses, mouthpiece, diaphram and valves is the way to go. A diaphram 1st stage is more cold water proof, but a piston maybe simpler. I am not too keen on the servo second stage. I understand they are extremely good breathers, but are they a bit more difficult to keep in tune? I also think that a mushroom exhaust valve would make servicing simpler. I particularly like the Nemrod Snark III concept in its exhaust valve. Size should not be an issue. The "large" DAs, Royals, Mistrals, etc. are so esthetic that I can't invision anything else. Good luck in your project. Allan
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Post by luis on Nov 29, 2005 14:30:41 GMT -8
Below I am recycling something I wrote earlier in reference to my opinion of the ideal modern DH. I think the Mentor or a copy of it is close. Here is a link to its manual: www.vintagedoublehose.com/downloads/MENTOR_INFO.pdfIt is nice sometimes to start with a clean slate, but sometimes I prefer to build on a well proven design. I have worked on a lot of original designs, but why reinvent the wheel (if you have a nice wheel to use as a pattern)? In reference to the first stage, I agree with RMannix. I like a flow through piston, but its geometry would be harder to fit in the conventional DH shape. The simplicity of a piston is beautiful (there is a reason why the Scubapro Mk 5 is the most copied 1st stage in the world), but the performance of the 1st stage in the Conshelf, Titan, Legend, etc., etc. is hard to beat. And parts availability is a major plus. Freezing temperature is not an issue in any type of 1st stage as long as the 1st stage is enclosed inside the air chamber of the second stage. A pneumatically (servo) assisted second stage are nice, but adds a level of complexity that is probably not necessary. I tend to like the large diaphragm with its mechanical advantage. It is beautifully simple. If I was going to build a regulator that looked like the Viking then I would look into the servo assisted demand valve. Again this brings me back to the Mentor. I have never seen one, don’t know how well it performs, but from the diagrams it looks great. I was looking at the parts break down on the Aqua Lung Mentor and it looks just like an upgraded Royal Aqua Master. It uses its own part numbers so I can’t confirm if they are the exact same parts, but the first stage parts looks identical to the Conshelf / RAM. It seems to even use the replaceable Conshelf volcano orifice I am planning on using in my new nozzle design. The second stage looks in part like a Voit Trieste II with the addition of an externally adjustable (and replaceable) volcano orifice. This will allow you to adjust spring tension from outside of the can with the diaphragm in place. It also has two LP ports, one HP port, and instead of a duckbill it has a large mushroom valve. Form what I can tell the Mentor basically incorporates all the improvements I would have redesigned into a new Royal Aqua Master II. It looks like a great unit!! Aqua Lung really blew it in not offering it to the public. I wish I knew the story behind it. Even better I wish I knew a way of getting one.
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Post by luis on Nov 29, 2005 14:38:59 GMT -8
Freezing temperature is not an issue in any type of 1st stage as long as the 1st stage is enclosed inside the air chamber of the second stage. This is one of the points were the modern Mistral totally blew it.
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Post by SeaRat on Nov 29, 2005 15:20:36 GMT -8
Let me throw in a few interesting possibilities. These are ones that have been in my mind for quite some time.
First, any double hose regulator has a disadvantage in certain positions against the single hose (with the second stage at the mouth) because of the difference in the water pressure between the regulator diaphragm and the center of the lungs. Years ago there was a paper written about how to eliminate this problem. With modern designs on the diaphragm, it should be easier now than ever to accomplish. There were two ways mentioned, both of which would work.
--Use an inverted regulator design (diaphragm higher than the lever in the water), and use a weighted diaphragm to offset the difference in pressure. This way has a disadvantage of putting the exhaust higher than the diaphragm, which could cause some leakage. But when swimming face toward the bottom, the weighted diaphragm pushes down against the demand lever, and slightly decreases the effort of inhalation. When the diver is swimming face toward the surface, the weight of the diaphragm would slightly offset the increased water pressure, and prevent water from being "pushed" to the diver's lungs.
--Use a lever system to weight the diaphragm in the normal swimming position. This would have the same effects as stated above, but on a normally-oriented regulator case.
I think I still have that paper somewhere in my files.
The other possibility is to use a lever system and a "Y" valve on the exhalation hose to use exhaled air for the BC. Exhalations have never been utilized since we went away from oral inflation, but this would be an advantage for a double hose regulator over a single hose.
Concerning the other remarks, I would keep the first stage inside the air chamber of the second stage, as an protection from freeze-up. I don't care whether it is a diaphragm or piston (I have and like both), but I do want the first stage balanced, and high-flow.
I think that current hoses are too short. If the regulator is properly positioned, then there needs to be enough hose to put it in the optimum position, and the second stage venturi should be one that can be adjusted for that hose length, or at least set up for a longer hose.
The inhalation resistence should be at about 1/2 inch cracking, going down from there. An effective venturi is actually the first single stage, double hose venturi design of the USD Overpressure Breathing regulator. This could be a hose-within-a-hose concept, with the hose in the mouthpiece directing air down the diver's mouth, much like the Scubapro or Dacor Pacer second stages allow air to go directly down the diver's mouth from the mouthpiece.
'Just some thoughts.
John
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Post by jrvance on Nov 29, 2005 17:27:42 GMT -8
also, make the reg compatible with 3500 psi tanks,(with a strong yoke) because the new PST High Pressure 80 is only about 20 inchsall, and would allow the reg to be much better positioned than an aluminum 80, although both tanks have diameters of 7.25 inches
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Post by luis on Nov 29, 2005 17:28:15 GMT -8
Oh yes, the hoses, mouthpiece, diaphragm and mushroom valves should be silicone. No duckbill. The hoses yellow and the mouthpiece black. We can have special edition hoses and mouthpiece made out of clear silicone. That is bound to freak someone out … ... as in what would a tech diver think of that…then again they may like it.
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Creed
Pro Diver
Posts: 189
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Post by Creed on Nov 29, 2005 17:30:34 GMT -8
Well, I guess I should talk about my design now. I based my ideas off of the new Mistral. Essentially, I am taking a Conshelf 1st stage body and replacing the spring retainer with a screw on 2nd stage. The 2nd stage would look much like the Aquamaster(two piece cylinder), with a smaller diameter. The hoses would connect the same way. The lp air is fed to the 2nd via a small hose, like the new Mistral. The advantages: no massive reengineering project, all of the replaceable parts are stock Conshelf(both 1st and 2nd) except for the duckbill and hose assembly, you have 1hp/3lp ports(more, if I use a later generation), it is designed for 4000psi, can be converted to DIN, the 1st stage is sealed away in the 2nd, etc. Disadvantages: There may be enough torque from the 2nd stage assembly to loosen the spring retainer. Not sure if this would be an issue or not. Conshelf 1sts can go pretty cheaply. I've got 4(with a load of metal 2nds) and I haven't paid over $100. So, I was hoping to make this a sort of DIY conversion kit. I've already got 2 guys who are interested in doing the brazing work. I'm just looking for someone to do the sheet metal forming for a prototype.
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Post by nemrod on Nov 30, 2005 0:58:34 GMT -8
I am not all hung up on the servo assisted thing, just think it is really the only way to get cracking effort down to single hose levels. Still, if one is practical, Conshelf parts in vintage styled cans that would be useable on actual vintage DA and RAM and the addition of the HP and LP outlets is all we really need. I like the idea of optional clear silicone hoses and mouthpieces. There is a lot of wasted movement it seems to me in the horseshoe and pivot shoes in a DA/RAM. There is a fair amount of friction there as well. Teflon coated surfaces and a more stable fulcrum would probably help big time as would perhaps a compound lever. I kinda like the idea of a weight balancing the diaphram but think a spring--acting as an over balance--for the main diaphram would work better and not be effected so much by gravity or movement of the diver and reduce waisted movement by keeping the diaphram up to the lever at all times. There are single hose units that use overbalance springs I am pretty sure. Yeah, it must be useable at pressures up to 4,000 psi and offer a conversion kit for DIN. I would prefer not to have any "New Mistral" like connecting hoses or any of that. Along the clear idea, if the housing were "Jet Air" like it could be made from clear plastic of the type used by Ikelite which is fairly tough. Neat--you can see the inards! As an option--lol. Stainless spring clips could be used to hold it together that could snap on and off or even stainless screws. James
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Post by RMannix on Nov 30, 2005 5:16:59 GMT -8
How about smooth bore hoses similar to modern BC hoses but of course larger diameter? the outside could have the new flat corrugations or appear vintage. this would allow hoses to be longer than necessary and trimmed as needed too. Seems the only double manifolds being manufactured now are the techie isolation manifolds with no center post. Doubt if they considered this on the New Mistral either.
Must accept standard replaceable mouthpiece.
Smaller box like a Trieste seems like a great idea, less volume should make it easier and faster to suck a vacuum and actuate.
the servo/pilot doesn't sound good to me, it's still a 2 hose and would be subject to freeflow too easily. Maybe if a pressure sensing line ran inside the supply hose to the mouthpiece. Would prefer simplicity and standard LP seat.
A removeable plug to allow fine tuning while assembled would be nice to have, especially during development.
Symmetrical: diaphragm should not need ears to contact the demand lever. A threaded box or ring allowing no tools whatsoever to open the box would be a nice touch. Not that I advocate the requirement to take apart underwater, but I really like to disassemble and clean diving salt water.
Most importantly if you use Lexan or another plastic for the box it will be difficult to make a gold plated commemorative version.
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Post by luis on Nov 30, 2005 8:13:41 GMT -8
Hi Creed I like your idea. Do you have any drawings or sketches that you can share? Do you need any help with drawings? I am not a draftsman (among other things, I am slow) but I do use AutoCAD.
The idea of using as many of the shelf parts (steeling from other regulators) as possible should keep cost down. My experience is that any low volume custom part you have to make will cost a lot more than mass produced parts you can buy; unless you can find the retired old machinist that used to work at your local aerospace company and he keeps his own lathe, etc. in his garage. I have known a couple of those guys in the past, but at this point I am out of luck. I think Broxton Chuck knows one of those guys.
As I mentioned, I do like pneumatically (servo / pilot) assisted demand valves, but they can be complicated and temperamental. A simpler alternative is a balanced second stage demand valve like Scubapro uses in several of its second stages. I have retrofitted several of my old Scubapro 109 and it is fairly simple clever mechanism. Again even this is more complicated than a basic down stream valve.
A balanced first stage is a most. The constant intermediate pressure of a balanced first stage can be adjusted to almost match the spring force of the basic down stream second stage.
On a related subject: my modified Royal Aqua Master 1st stage body is intended to use the 4000 psi Conshelf yoke or Conshelf DIN fitting conversion kit (that DIN conversion kit is not cheap). It would not have any problems with 3500 psi service since all the 1st stage parts are modern Conshelf parts. Now if I could just find that local retired machinist I am looking for… I would have a prototype soon.
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Buzz
Senior Diver
Posts: 64
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Post by Buzz on Nov 30, 2005 8:28:58 GMT -8
Fantastic !!!! these are some realy great suggestions. These will take a while to digest.... keep them coming To give everyone a glimps of the parameters that are under consideration at present, here is what I have been thinking. - All metal pieces to be stainless (polished or brushed) Vintage shape and size!!! - Body (or can) halves to be held together with socket head cap screws for easy opening (similar to Dacor double hose design). - Internals to be easily dissassembled with a minimum of tools (standard tools, no special tools) - 3 LP ports/1 HP port - Yoke (with big knob) and first stage designed for 4500 psi. - Yellow hoses (to begin with) Yellow mouthpiece. Hoses to have a screw-on connection to the mouth- piece and regulator. - All hoses, valves, mouthpiece to be silicone - Mouthpiece to be two pieces (hard silicone body using standard off-the-shelf mouth insert) - Manually operated purge by pulling on the inhale hose - Manually operated over-balance fine adjust lever that is easy to reach, but with a subdued look and placed so as not to detract from the vintage look. Also a coarse adjust small knob (or screw) that can be made external to the reg. If any of these gives heartburn to anyone.....please speak up....love to hear from you ;D Buzz
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