|
Post by nemrod on Nov 30, 2005 10:44:04 GMT -8
About those hoses, I think it would not be wise to stray very far from the standard USD hose design/size/opening diameter/appearance. They are virtually perfect. The one thing that I hate about the New Mistral the most is the giant Shop Vac hoses. I really do not believe those corugations in the inside hurt anything but whatever about that the outside should be the same appearence as USD hoses and should be compatible with vintage units so they can be retrofitted.. I don't much like screwing stuff together in saltwater---does not work. The standard 1 inch X 1.5 inch slip over hoses are just fine and are one of the things that probably cannot be improooved upon without causing other problems. Maybe make them a alittle longer or offer a long and a short etc and of course the silicone will make themso much more flexible anyway. Keep the mouthpiece similar to curent vintage units as well so it can be retrofitted. It is light, simple, and works fine. The only thing that might be worth incorporating might be a removable bite piece--maybe. Nothing spils the vintage look (and performance) faster than those ugly rebreather hoses and honking huge mouthpiece things. The only reason I suggested plastic is that it can be injection molded rapidly and can be made in colors or even clear. Metal is always better of course but a plastic/composite can on a metal body would be acceptable--maybe---. James
|
|
|
Post by nemrod on Nov 30, 2005 10:49:22 GMT -8
One other thing, design by commitee is how you get something to look like the south end of a jackarse going north! At some point one must decide---this is how it will be though that is not where I think you are now. From a vintage point or any point for that matter--asthetics are extremely important. If it does not look right it is doomed out of the gate. People don't readily admit it but looks count more than anything else but in the end it must also be good on the inside where it counts for real. James
|
|
|
Post by luis on Nov 30, 2005 11:01:34 GMT -8
- All metal pieces to be stainless (polished or brushed) Vintage shape and size!!! If any of these gives heartburn to anyone.....please speak up....love to hear from you ;D Buzz I would not used stainless for any machined part that are assembled in close contact. For the cans would probably be ok, but there are several reasons why most regulators have been made of bronze / brass. Just to mention a few: • The cost and difficulty of machining stainless is higher • Most stainless will require passivation treatment to reduce corrosion, even 316 will spot rust (and you don’t want to pay for something like 17-4PH) • Stainless threaded parts will cease together in a salt water environment if not serviced regularly (or use anti-cease compounds, we have used Teflon tape for isolation). It is not too bad in small hardware. • I don’t know about the current price (per pound) of stainless vs. bronze I have taken apart chrome plated bronze (with highly deteriorated chrome plating) after a couple of decades of neglect with out much trouble. I remember in the 70’s Sportways introduced a stainless first stage. That thing seemed like it wanted to rust into one solid piece of junk if you didn’t service it often. Bronze parts should be chrome plated, but even bare bronze holds up ok in a marine environment. Stainless is good for springs, for first stage pistons (that are isolated from other metals by O-rings), levers that require the strength (but can not freeze to the adjacent part), and other similar parts, but I would be very careful of using it for other parts. Stainless screws into a bronze piece is normally ok (look at the adjusting stud on a Mistral). Of the shelf stainless hardware is easily replaced. Now that we are friends with the Russians, the cost of titanium is becoming more reasonable, but designing with titanium opens a whole different can of worms. It is a great material in a corrosive salt environment, but machining it can be a challenge. Like I said, there are very good reasons why most regulators are chrome plated bronze. If it sounds like stainless can give me“heartburn” is because it can. Many stainless alloys have great properties, but it is not a one size fits all solution.
|
|
|
Post by treasureman on Nov 30, 2005 11:05:30 GMT -8
The horns should have a forward rake so as to remove stree and strain on the hoses. Instead of a duckbill, perhaps some sort of wagon wheel with valve could be made to fit into the the exhaust horn in the round portion. Ther is a small inner edge in the exhaust horn where a clip or retainer ring could be placed. No more sucked in duckbills.
Just my two cents worth
|
|
|
Post by jrvance on Nov 30, 2005 14:33:07 GMT -8
How about using the respirator hoses still produced like the ones seakrakken was selling or standard anestesia hoses, also, make the mouthpeice out of brass or bronze and use the coupling like fitting like the MEDI, that way the mouthpeice lasts forever and you only need to buy a replacement standard regulator mouthpeice
|
|
Creed
Pro Diver
Posts: 189
|
Post by Creed on Nov 30, 2005 16:06:09 GMT -8
Hi Creed I like your idea. Thanks. As far as I can see, if the price of the "modern" reg exceeds that of a Royal AM, why bother? So I went for something that would a) not require designing a new 1st stage from scratch, and b) not require extensive alteration of the "donor reg." Yeah, but I have no way to get it into the PC. I'm in Iowa, and my scanner is in Kansas. I will try to get some freebie cad program loaded and maybe flesh out a design. I happen to know quite a few people with access to machine shops who could do lathe work, but I don't know anyone who can form the box pieces. There are a few shops in Wichita that do this kind of thing for the airplane manufacturers, so when I have time I am going to try and visit them. James, do you know of anyone who does that work there? I was just going to use the standard 2nd stage Conshelf valve assembly, including the diaphram. I can't decide on the net effect on WOB would be, though. It seems like the smaller volume of air in the box(as compared to a AM) would make triggering the 2nd valve easier, but that's just a layman's guess.
|
|
Creed
Pro Diver
Posts: 189
|
Post by Creed on Nov 30, 2005 16:20:36 GMT -8
I would prefer not to have any "New Mistral" like connecting hoses or any of that. I agree, but it was the only way I could see to mount the second stage on the 1st stage body without a total redesign of the parts. Initially, I was going to base it on more of a Calypso style 90 degree body. But getting one cast would be a major undertaking. Just call it a triple hose regulator.
|
|
Creed
Pro Diver
Posts: 189
|
Post by Creed on Nov 30, 2005 16:22:26 GMT -8
Metal is always better of course but a plastic/composite can on a metal body would be acceptable--maybe---. James You're caving in, James! Next time you post a picture, I bet you have a plastic Mares 2nd in your mouth!
|
|
|
Post by seakrakken on Nov 30, 2005 17:29:12 GMT -8
What if we could make a mouthpiece that looked vintage but, also housed a second stage inside of it using a hose within a hose to do it?
|
|
|
Post by luis on Nov 30, 2005 17:41:29 GMT -8
I was just going to use the standard 2nd stage Conshelf valve assembly, including the diaphram. I can't decide on the net effect on WOB would be, though. It seems like the smaller volume of air in the box(as compared to a AM) would make triggering the 2nd valve easier, but that's just a layman's guess. I am going to recycle something I wrote a while back: "...naturaly they would breath better as they do not have that large diaphragm to move..." Actually the large diaphragm is what helps old two hose regulators breath easier. The force produced by the diagram (to move the horse shoe lever) is equal to the pressure differential times the area of the diaphragm. Therefore, the larger the area the less amount of pressure drop/ suction required to move the lever.
New regulators with small diaphragms require fine tuning and other mechanical advantages (pilot valves, etc.) that was not as critical with a big diaphragm. The diaphragm gave you the mechanical advantage. The original Mistral relied on that size diaphragm. I don’t think that reducing the volume of a Royal AM will make a noticeable difference, but that can be easily tested. I may have to try to get some plastic (like nylon, Delrin, or solid rubber ) that I can easily cut to fit into the empty spaces of one of my Royals and hold it in place with some sticky back tape. Obviously, I will have to be careful not to interfere with the mechanical movement of the second stage. What is WOB?
|
|
|
Post by Ron Hearn on Nov 30, 2005 19:16:34 GMT -8
Hi
To reinvent the double hose regulator to a point that its better than what was or what is today is going to be a great taskand I wish you the best of luck. Personally I don't beleave that the diving community would be interested. The market has moved on into rebreathers and that's were the market focus is. The reintroduction of the Mistral is and should be a prime example to you of what sells. The new Mistral was a flop and the cost to get it to market I'm sure out weighed its profits to Aqua Lung.
Good Luck
|
|
Creed
Pro Diver
Posts: 189
|
Post by Creed on Nov 30, 2005 20:28:02 GMT -8
Work of breathing.
|
|
|
Post by seakrakken on Nov 30, 2005 20:54:53 GMT -8
This is an effort to find what our intended market niche is interested in having. There will not be a large production run on the project. I should imagine, if it actually becomes available, it will go down in history as a lark. Maybe, not a bad name for this project. What do you think Buzz?
|
|
|
Post by duckbill on Nov 30, 2005 22:56:58 GMT -8
Most stainless will require passivation treatment to reduce corrosion, even 316 will spot rust (and you don’t want to pay for something like 17-4PH) Passivating stainless is a one-time event, and VERY simple. The finished part(s) is soaked in nitric acid(if I recall correctly) for about 20 minutes to dissolve ferrous steel particles imbedded into the surface of the SS during machining. • Stainless threaded parts will cease together in a salt water environment if not serviced regularly (or use anti-cease compounds, we have used Teflon tape for isolation). It is not too bad in small hardware. Stainless on stainless will seize and gall every time. Any vintage diver who has had the bright idea of using SS bolts and nuts on their cylinder bands has discovered this phenomenon if they have disassembled and reassembled them a few times. Sometimes it gets so bad that the bolt has to be cut of sheared to remove. I ended up using galvanized fasteners on mine. If they rust, they are cheap. I have found small SS nuts and bolts just as susceptible to galling and seizing. Even if you use stainless parts and must use threaded fasteners, use brass. I would second the suggestion of using the SCBA respirator hose- compatible mouthpieces. Nearly everything becomes obsolete eventually, so think long term. How many things can you think of which use hoses 1" on one end and 1 1/2" on the other, other than some of the old double-hose regs? 1" on both ends can be found even when the reproduction reg hoses go bye-bye again. The Hope-Page mouthpiece is ideal in many ways. Screw together connections for 1" hoses, and designed for a standard, replaceable SCUBA regulator mouthpiece. I think it will even take standard size one-way mushroom valves.
|
|
|
Post by SeaRat on Nov 30, 2005 23:04:21 GMT -8
One design feature that both the Sportsways Duel Air and Hydro Twin, and the New Mistral, share is an asymetry of positioning. Whereas the Aquamaster and Mistral designs, and most other double hose regulators, have the first stage directly in the center of the second stage box, these two design examples (Sportsways and New Mistral) drop the second stage in position. This gives the regulator about a 1-2 inch advantage over other double hose regulators for positioning on the back, and thereby decreases the water pressure differential between the regulator and the center of the lungs. Maybe this is something you might also want to use in this new design.
John
|
|