Carbon Fiber Backplates?

[tech_diver]

I got my CF plate simply because I like the way it looks. Anyone who has a problem with that is free to **** a bag of *****.

I can do better than CF for cost and questionable benefit. I got my hands on a titanium back plate. It's heavier than aluminum but lighter than steel and would retail for about $500.

It is the ultimate in expensive uselessness. But on the boat someone asks me what plate I dive, I get to look at them like Batman and say, "Titanium."

 

[Diving Dubai]

I have an ongoing debate with my dive buddy regarding the Bonex scooters and their CF hulls. And it comes down to what "problem" does the CF hull solve and is it worth the extra cost vs Alum or PVC? The benefits of CF are pretty much wasted on an application that is merely static (unlike a bike frame, or racing applications). Sure, they look cool but are you driving your SUV over them?

Interesting you brought this up. Bonex Scooters are high on my want list to replace mine and my wife's Dive X Sierra's.. The Reference RS has no competition regarding weight, thrust run time and manoeuvrability (for our needs)

I have a real issue with the CF tube, I've sat down with the Bonex people at a show in Germany and had a discussion with one of their engineers (the sales person left as the discussion went over their head)

I hear their arguments, however I worry that is real world use it won't have the damage tolerance of my ali tube against bumps and scrapes. Puncture the thin protective glass layer and start to damage the CF strands and it really does start to have an impact.

I asked for an Ali tube but to no avail. I really REALLY want one (two) but the CF tube doesn't give me confidence for longevity

 

[NAM001]

DSS made a CF backplate. I have one and have not used it for years. its OK just the steel one works best for me.

 

[saxman242]

Puncture the thin protective glass layer and start to damage the CF strands and it really does start to have an impact.

Surprises me that they don't do an outer kevlar layer instead of glass

 

[Manatee Diver]

$2000 dollar flight. $1500 lodging. $1000 diving costs.

Overweight checked bag fee? TOO MUCH!

At $400 round trip is adds up. And I would rather give my money to scuba companies.

Oh come on now

I can take a full SM kit (2 1st sages) plus a spare complete octopus (All Apex XTX 50) and basic tools and still be under the weight limit

You'd save more weight by converting 1 reg set from A clamp to Din

0.5 lbs (220g) is nothing

It all adds up, the last trip I took I was evaluating "Do I really need this?" because was at right at the weight limit on my diving bag.

So in reality a cam band induces more stress

Not really you are forgetting that the stress of a camband is divided over a much greater area. Where as the with a STA or a doubles rig all the force is on the area around those two bolts.

Personally I wear carbon fiber every day in all conditions, including getting soaked in both fresh and salt water. I get delamination, but you are talking about a leg that is used 12-16 hours a day having to deal with hundreds of pounds of forces for miles at a time. Aircraft like the 787 fly millions of miles a year taking the full force of pressurization and along the wings, carbon fiber has proven itself to be very resilient.

 

[jadairiii]

Interesting you brought this up. Bonex Scooters are high on my want list to replace mine and my wife's Dive X Sierra's.. .

As I posted, I own a Suex and should I replace it, I will buy another. I have looked inside the Bonex (my buddy's) and was somewhat surprised that it seems a tad cheap (for lack of a better word), especially some of the connectors and hardware compared to my older Suex. Which would cause me concern as to what else did they cut back on for the CF tube? Plus I like the way the nose attaches to the Suex vs the Bonex.

As hard as I am on my Suex I know for sure I would have had to purchase a new tube had I had a CF tube (or watch bike videos on repairing CF cracks), just by the gouges out of my PVC.

 

[Diving Dubai]

It all adds up, the last trip I took I was evaluating "Do I really need this?" because was at right at the weight limit on my diving bag.

I respect your stand point. But given I make 7 - 10 international trips with my and my wife's gear each my opinion on 0.5lbs differs

Not really you are forgetting that the stress of a camband is divided over a much greater area. Where as the with a STA or a doubles rig all the force is on the area around those two bolts.

With respect I'm not forgetting. A cam band is trying to fold the backplate around a tank, the surface area increased this effect, no load shedding/ A nut and bolt in this case (and there will be two which dissipate the torsional moment) have less because its in compression. I've over simplified this. I like to think I know what I'm talking about here, because none of the aircraft I made design calcs on have crashed (because of my failures)

Aircraft like the 787 fly millions of miles a year taking the full force of pressurization and along the wings, carbon fiber has proven itself to be very resilient.

Yes because its very much designed but in a much different environment - trust me on this, with Harrier, F18, Airbus 320, 330, 340 & Boeing 777 we went thorough massive testing and redesign on components. You'd be surprised how often the test rigs proved that our models were flawed or that we weren't as good as we thought we were. Coming in on a Monday Morning to a broken component on my desk was always a joy!

Pardon me if I cynically don't believe a CF backplate is a great idea. In the short term maybe, long term, Nah.

But it does look shiny

 

[Diving Dubai]

Surprises me that they don't do an outer kevlar layer instead of glass

You'd still need to encase it in resin (I'm no expert on Kevlar) The glass layer is just a tell tale, if the resin is damaged but not the glass layer, you can patch up the resin. If the glass is damaged, then the underlying CF layers maybe damaged.

The Glass layer isn't structural its almost (but not) sacrificial

 

[Manatee Diver]

I respect your stand point. But given I make 7 - 10 international trips with my and my wife's gear each my opinion on 0.5lbs differs

0.5lbs is the start there are lighter rigs than the Halcyon, someone mentioned they had a CF plate that was 0.5lbs that is a full 1.5lbs less than the lightest AL plate that I am aware of. Add in lighter weight titanium regs you can make enough of a difference that you can add more items. For example taking a boat coat on a trip where you might need it vs leaving it behind because you don't have enough weight.

With respect I'm not forgetting. A cam band is trying to fold the backplate around a tank, the surface area increased this effect, no load shedding/ A nut and bolt in this case (and there will be two which dissipate the torsional moment) have less because its in compression. I've over simplified this. I like to think I know what I'm talking about here, because none of the aircraft I made design calcs on have crashed (because of my failures)

And I would argue that you are either vastly overestimating the forces, or vastly underestimating the strength. You can make backplates out of freaking kydex. I wouldn't want to attach a pair of LP121s to a CF backplate, but I am quite sure that it has the strength to handle an average single tank.

Pardon me if I cynically don't believe a CF backplate is a great idea. In the short term maybe, long term, Nah.

It may not last forever, but sometimes you are willing to give a little durability in exchange for other benefits.

 

[Diving Dubai]

And I would argue that you are either vastly overestimating the forces, or vastly underestimating the strength. You can make backplates out of freaking kydex. I wouldn't want to attach a pair of LP121s to a CF backplate, but I am quite sure that it has the strength to handle an average single tank.

As I said - over simplified (clearly not enough)

You argued that a bolt was a greater stress point, than cam bands I was just trying to demonstrate why in this case it isn't. I wasn't saying the material couldn't take the load, that was you.