'U' v 'O' shaped wings - does it matter?

[cool_hardware52]

What advantage does the U-shaped bladder have over the O-shaped bladder?

You're asking if more difficult air migration will really be a problem. What would it solve??

Jonnythan,

In my experience the advantages of a "U" over an "O" is in the manufacturing processes, and compromises that are forced by a Donut design.

Most (not all) Donut wings are welded from a single layer of Urethane coated Nylon.

The advantages of this approach is there is no need to be able to access or install an inner bladder, because there isn't any, and they can't trap water between the inner bladder, and outer shell.

The downsides of this approach are:

The range of urethane coated materials available is limited

The shapes possible are impacted by the need to weld, as opposed to sew

Single bladder wings are in many cases impossible to repair, requiring replacement.

The advantages of "Double Bladder" (not redundant bladder) designs are:

Much more robust materials are available, ex 1065 denier Ballist nylons instead of ~400 denier nylons coated with maybe .001-.003 of Urethane. Thick urethane inner bladders .012" vs maybe .001-.003 of Urethane on a single bladder type.

More freedom in final shape, because the outer shell is sewn, not welded. Ever seen a tailored suit that was welded?

Ease of repair. Because the inner bladder is easily accessible, and not highly stressed, pin holes etc are routinely fixed with AquaSeal. Even if the inner bladder is beyond repair a replacement is ~$30.

The downsides of "Double Bladder" designs are:

Cost

Difficulties making "Donuts" Donut type double bladder designs are possible, but require a full perimeter zipper, either around the outside, or inside. Zippers are a weak link in any sewn item. (Ever have a zipper fail in say a dive bag, sleeping bag, wetsuit?) We use the largest, toughest molded tooth zipper made (#10 YKK), but these don't like to make small radius bends around the inside of a narrow singles wing.


Donuts don't suffer from a performace problem, they work fine. It's the construction compromises that I don't like.

In my opinion, a well designed, narrow, singles specific wing, with a central inflator and a "right sized" inner bladder will be very close in performance to a Donut. The advantages of the Double Bladder design outweighs any small advantage in ease of venting.



Tobin

 

[cool_hardware52]

The plastic inserts in the DSS plate are making a feature of a cost savings - it's cheaper and faster to mold and insert plastic bits than it is to finish the metal. If they ever fall out, get ready to get out your file.

Henry,

I usually just bite my tonge in the face of this sort of uniformed spewage, but

You are displaying your ignorance here. Have you ever seen our plates? Are you aware that the "Plastic bits" you reference are infact overmolded directly onto the plate. By this I mean the plate is actually IN THE MOLDING MACHINE when we make them?

Do you know for a fact that individually molding 4 seperate parts, one on each corner of each plate, i.e. each plate visits the molding press 4 times, is faster and cheaper than passing the plate over our deburring bench? Wow I'm impressed, you must have acces to our time studies, and found something I missed........

Deburring is a chore, so much so infact I built a special machine to do it, as we still have to deburr the tank strap slots and the other penetrations in our plate. I can guarrantee you I can deburr a plate faster than I can cycle a molding machine 4 times.

Fall out? They can't, they are part of the plate!

Why do I bother? It makes a better product.


Tobin

 

[Tanked Monkey]

Then you can count me as favoring the "O" for singles. I have Eclipse 30# and 40# wings and love them. I dive a "U" for doubles (Explorer and Abyss) until Halcyon decides to make and "O" for doubles.

Hmmmm, interesting that you should say that about wanting an "O" for doubles. I have seen a prototype from a certain major manufacturer (who will remain nameless) of a doubles "O" wing :yelclap: It's still being field tested right now. Hopefully it will be on the market by the time I get a doubles rig. <fingers crossed>

Mike

 

[Grajan]

Tobin,
I'm all for having manufacturers engaged in the board but there are times when standing back and learning from the discussion might be (have been.....) a wise move.

We have already had an extensive discussion offline and you are clearly not an unbiased consumer here so please try not to derail what was shaping up to be a useful and educational thread.

Thanks

 

[JeffG]

you are clearly not an unbiased consumer here so please try not to derail what was shaping up to be a useful and educational thread.

I appreciate that he is trying to squash bad information, and he has every right to do so.

 

[jonnythan]

I appreciate that he is trying to squash bad information, and he has every right to do so.

I agree. I think Henryville was talking out of his butt and Tobin had every right to defend his product from libel.

Henryville is of course welcome to prove his point..

 

[jetfixer]

Grajan, I thought Tobin's input was very informative and not pushing his product. Please dont discourage the manufacturers from participating.

 

[Grajan]

Completely agreed - the damage was done by then, as a clearly biased observer it would have been better to keep out in the first place - then there would have been no misinformation to squash......

I got a lot of great info before this thread went off the rails. Thanks to all.

I appreciate that he is trying to squash bad information, and he has every right to do so.

 

[Rick Murchison]

My Stiletto has a U wing and is a single tank rig. Would you mind telling me why you don't like to match a single tank with a U wing?

U wing tends to taco more than O wing on single tank
U wing tends to trap gas on one side when maeuvering for that perfect photo in a head down position, upsetting the neutral dynamic stability essential to such a task
O wing, since it transfers gas side-to-side easily when head down is self stabilizing
Rick

 

[MXGratefulDiver]

IIRC, the Pioneer has no separate bladder, while the DSS does. I don't know if the whole DSS bladder is therefore replaceable but if it is you might consider that an advantage.

It's replaceable. How do I know? Because I replaced mine after the TSA monkeys damaged my wing on my return from Roatan a few weeks ago. I had a new bladder from Tobin within less than a week, and it took all of 10 minutes to replace the damaged one.

On the plates, I have several from various makers including Halcyon and I have found the finishing of the Halcyon slots among the best I have owned (FredT is number one.) The plastic inserts in the DSS plate are making a feature of a cost savings - it's cheaper and faster to mold and insert plastic bits than it is to finish the metal. If they ever fall out, get ready to get out your file.

That would be a neat trick ... the inserts are built right into the plate. I imagine you could remove them with a dremel tool or something, but I don't think it would be possible for them to "fall out".

BTW - I also own a FredT plate, and although the quality of that plate is impressive, I prefer both the workmanship and features of the DSS plate.

... Bob (Grateful Diver)