Patrick:
If you want to split hairs Patrick, the center panel in our wings is really about 3 1/4 inches wide, but it can vary just a bit due to it being a sewn feature. I'd guess that the center panel in your wing is slightly wider than 2 inch webbing, i.e. 2+ inches.
If you understand the geometry involved it is difficult to argue a 1/2 inch at this point has much effect the inflated volume.
Consider the volume in the wing a this point.
The space occuppied by the wing where the tank meets the plate is roughly triangular.
Does a triangle 1/2 inch deep x maybe a 1/4 tall the lenght of the tank really contain meaningful volume? (1/2 x 1/4)/2 = .0625 sq inches x 16 inches (lenght of the plate) = 1 cubic inch
1 cubic x 2 (each side of the tank) 2 cubic inches of gas will provide (2/1728) x 63 = .08 lbs of lift, not enough to "shift the paradigm" very far. Rerun the numbers using 3/4 inch per side, and you have added ~0.11 lbs of lift compared to a wing using a 3 1/2 inch center panel.
Now let's assume that due to your required use of a STA, that the added volume on your ~2 inch center panel wing, where the tank meets the plate, is really 3/4 wide by 1 inch tall. These are generous values. The resulting volume is still less than 1/2 lbs of lift.
That's not the case the further you move from the center line of the tank. If the center panel is approximately as wide as the cylinder, i.e. 6-7-8 inches, the tank does little or nothing to constrain the inflated shape of the wing. This wide center panel is typical of the wings you market, and all others I know of, that predate our LCD wings.
When we reduced the center panel from 7-8" i.e."as wide as the cylinder" to ~ 3 inches the effects were pretty dramatic. Reducing it from ~3 inches to ~2 inches due to the geometry has almost no effect.
Patrick:
It is insurance just in case you need to get access to the bladder. About two years ago Halcyon came out with some prototype Evolve wings that had no zipper or access to the bladder. They were tortured for that design on this same list.
Interesting, I had no idea Halcyon had tried this. I'm sure they were tortured. New ideas are tough for some to accept.
More importantly; did the wings work? Were the bladders tough enough? Did they suffer routine failures? Has the MachV bladder suffered routine failures?
I know the 22 mil bladders in our Torus wings are performing well. We've had two out of hundreds returned, both replaced same day. Again, most divers don't carry a spare bladder, or the tools required to change the fittings. Most bladder repairs and replacements end up either at the dive shop or returned to the manufacturer, whether there is a zipper or not. Because we have the capacity in house to do these repairs the down time for the user, in the rare event repair is necessary, is minimal.
We don't need to ship the wing cross county, and export it to foreign lands, and have it lost in customs and then sent back across the country. We just fix them, and return it to the customer.
Patrick:
In my opinion, the only time you do not use a zipper is if you use a bladderless wing.
Good Point. Most BC's and many wings sold today don't have access to the bladder. "Single Bladder" or as you prefer "bladderless" wings do not provide access to the bladder. Are these known to routinely fail?
Patrick:
If zippers are not needed, why don't you remove them from all your other wings? It will save time in sewing and cost in the zipper.
I've explained why in depth many times. Short zippers in the top arc of a horeshoe wing is a very different thing than a 360 degree zipper in the center panel of a horeshoe wing. We use only #10 YKK zippers when we install a zipper. What do you use for a zipper in the Mach V?
A
Patrick:
lso, for what it is woth, OxyCheq has been the proponent for longer, slimmer wings since we began making wings ---longer than three years.
If our innovative design, i.e. using the plate and cylinder to control the inflated shape of the wing is so little value why are you reacting by having your line redesigned?
Patrick:
You shaved a couple of inches in width from my Sig Series wing and now claim to be the originator of narrow wings. I shave a couple of inches from your wing width and now it is insignificant.
1/2 inch or even 3/4 inch a side is insignificant down where the tank meets the plate, see above, do the math. 2-3 inches per side, from out board of the cylinder, is significant.
Can you show me any wing Oxycheq markets that predates our LCD wings where the center panel was significantly narrower than the cylinder?
Tobin