New DSV Mouthpiece Coming soon!

[uwstlth]

Good discussion, looking really sharp! The message about torque (or jaw fatigue) is exactly why DSV designers have designed threaded rings on the ends of a DSV where the hoses attach in stead of zip ties etc directly to the barrel as I have mentioned in previous posts. This allows the diver to adjust the pressure from either a downward or upward force whilst it is in your face... and maintain a closed loop. There has been years of research to support this design idea

As well some threaded rings are made out of brass and act as a built-in weight to make the DSV neutral in water (as I dive with).

You guys are awesome, the thought and process you have gone through with this project is truly inspiring, KEEP IT UP!!!!

[luis]

Good discussion, looking really sharp! The message about torque (or jaw fatigue) is exactly why DSV designers have designed threaded rings on the ends of a DSV where the hoses attach in stead of zip ties etc directly to the barrel as I have mentioned in previous posts. This allows the diver to adjust the pressure from either a downward or upward force whilst it is in your face... and maintain a closed loop. There has been years of research to support this design idea

As well some threaded rings are made out of brass and act as a built-in weight to make the DSV neutral in water (as I dive with).

You guys are awesome, the thought and process you have gone through with this project is truly inspiring, KEEP IT UP!!!!

Yes, I totally agree, but that is also part of the reason why rebreather DSV start at about $300 and go up from there. As part of the price of a $5,000 rebreather the cost of the DSV is not as significant, but I was not about to design a DSV that cost more than half of the cost of the regulator.

We had to explore some alternate design options and they are in progress.

The cost of an item is normally proportional to the parts count and complexity of the parts in the item. Every extra part adds to the cost (and complexity).

If you read my post with some of the emails quotes, you will see some of the other details I am working on. A quick release clamp would actually accomplish the same purpose, would be more economical, and it would have several other advantages.

More to follow, but some things have to come one step at a time at a time. I have nothing to do with the production, but I do understand the need of a positive cash flow to move forward. The DSV is ready for production and it can use a number of hose clamps that are available at the moment. Following it up with a quick release clamp will depend on several issues (technical, financial, and the combination of both).


Sometimes the solution has to be a procedural solution. Sometimes it is just not cost effective to have the ideal piece of hardware. Our military has been learning that in a hard way.
Note: this last paragraph is actually somewhat related to my primary job.

[Bryan]

It took me 2 dives to get the mouthpiece in the position that was comfortable for me and I never changed it for the rest of the week of diving. I think most divers will have a similar experience.

It would have been easy to duplicate the DSV's used in the rebreather community. But there is ZERO market for a $500.00 mouthpiece in the double hose world. Plus with the $420.00 you saved buying the Argonaut DSV you can buy a few more double hose regulators.

[luis]

uwstlth,

That is great feedback. Please keep it coming.

I didn’t realize that Bryan was also going to answer.

Just to add some related information. Rob and I looked once at trying to reproduce just the Hope-Page style mouthpiece with the threaded connection (no DSV feature) and the cost of all the parts just added up to a price point that didn’t seem reasonable.

[luis]

DSV (Dive Surface Valve) style of mouthpiece

Features:

1) Simple design with minimal number of parts to increase reliability and keep production cost down.
2) Closing feature is accomplish by rotating hose / hose clamp assembly. No lever sticking out of the front of the assembly.
3) There is a removable mechanical stop that limits the rotation and gives positive feedback that the DSV is open or closed. The stop also keeps the two cylinder in alignment. The stop is removed in order to disassemble the DSV.
4) Water in the mouthpiece byte tube can be purged before opening mouthpiece. This keeps the loop completely dry.
5) There are traditional check valves (inlet and outlet) on both sides of the mouthpiece, but if the diver purges the little water inside the byte tube, there will never be any water entering either hose that will need purging. Purging by just blowing (or raising the MP above the can) is always possible as with a traditional MP.
6) Mouthpiece was tested as completely water tight. Test showed that after 25 consecutive dives, regulator and inlet air hose were totally dry.
7) There is no special maintenance required for the mouthpiece and since the regulator will be kept dryer, the maintenance on it will be reduced.
8 ) The mouthpiece has five O-rings:
a) The two on the wagon wheel valves are static O-ring and will probably outlast the silicone mushroom valve.
b) There are two radial O-ring that provide a controlled amount of friction to the DSV rotation (They are not sealing O-rings).
c) There is one O-ring that seals on the mouthpiece opening (or in the closed position). This O-ring can be easily inspected while rotating the DSV and it is easily replaced. The O-ring is captured, it only sees about 10% to 15% compression during operation, and has smooth surface to slide into with a nice rounded edge.
9) Air passage in mouthpiece is very large and optimized to minimize flow resistance.
10) Flow diverter provides smooth flow transition into and out of divers mouth.
The inlet and outlet ramp angle are different. They are designed for the difference in the flow velocity.
11) Flow diverter is optimized to take full advantage of Argonaut Kraken maximum possible venturi flow. See note.
12) Several flow diverter were designed and tested. The attached sketch shows three of the flow diverters tested. They have different height and flow angle. The 2 dimensional drawing is a bit misleading about the true flow path areas, but it should give an idea of the design.


Note: The Argonaut Kraken was specifically design to have a very adjustable cracking effort and venturi flow.

The lowest reasonable cracking effort is limited by the radius of the exhaust valve (about 1/2”). If the cracking effort is adjusted lower than 1/2 inWC, the regulator will tend to have a light free flow when the top edge of the exhaust is higher than the center of the diaphragm.

The amount venturi flow had to be limited to avoid the excessive flow from blowing past the mouthpiece and out the exhaust. The flow diverter in the mouthpiece was specifically designed to take advantage of the strong venturi flow the Argonaut can be adjusted to. No excessive air is allowed to blow-by past the mouthpiece. All the air is directed towards the diver. Once flow is initiated, only the air used by the diver will be supplied with minimum inhalation effort (with no wasted air out the exhaust).

The sketch below shows three different diverter that were analyzed and 3D model prototypes were tested.

[uwstlth]

uwstlth,

That is great feedback. Please keep it coming.

I didn’t realize that Bryan was also going to answer.

Just to add some related information. Rob and I looked once at trying to reproduce just the Hope-Page style mouthpiece with the threaded connection (no DSV feature) and the cost of all the parts just added up to a price point that didn’t seem reasonable.

You've got it Luis, anything I can do to help I'm happy to do (love your design work!) I dive 3 different DSVs on 3 differnet rebreathers regularly; Drager (on a MK25), Scott (old MK15), PRISM 1st gen (on my MK15.5). Each is different in design but essentially the same operation. The Drager DSV is the smallest and lightest being all POM with minimal SS snap rings but the most complex with regard to servicing and requires special tools to do so. The Scott is the most simplistic and easy to service with a simple slotted screw driver and use. The PRISM is inbetween but is the heaviest and most neutral in water. So each has it +/- and I wouldn't say any is better than the other however. They each serve a niche purpose and that's what they were designed to do.

I agree with Brian, it;'s absolutely freakin' ridiculous what places like Gloem charge for a DSV, it's stupid criminal. But some guys who have tech boners for RB gear pay it so they charge it- stupid. I think Martin at Tecme ( http://www.tecme.de/ )has decent pricing on his stuff and if you want someone to chat with about tooling etc, he's a solid guy and knows Drager better than anyone.

One other thing that seems to be missing is an external lever to rotate the internal barrel. That would require a redesign to have the hoses mounted to the external barrel. Not trying to throw any wrenches but the reason for this is also so that the hoses can stay in place whilst the loop is opened and closed once a satisfactory hose position has been determined by the diver and locked into place (but can be changed on the fly again if needed), but I'm sure you know this.

Keep up the great work, I'm excited to see the progress and hope to buy one of these once they reach production stage-Kevin

P.S. I do understand and agree the cost of tooling etc for a single person like Brian is a big factor and respect that. I too see the military waste daily

[luis]

One other thing that seems to be missing is an external lever to rotate the internal barrel. That would require a redesign to have the hoses mounted to the external barrel. Not trying to throw any wrenches but the reason for this is also so that the hoses can stay in place whilst the loop is opened and closed once a satisfactory hose position has been determined by the diver and locked into place (but can be changed on the fly again if needed), but I'm sure you know this.

Yes, that was done intentional by design. See line #2 under the features post above.

I am aware of at least one rebreather DSV that is based on a similar design principle (the Inspiration DSV, the diver also rotates the hoses to close it: http://www.apdiving.com/en/rebreathers/features/ ).

During my tradeoffs of alternatives study, I decided that my design would reduce the number of parts and keep it simple. Keeping it simple normally translates into lower cost, improve reliability, and easier maintenance. I think that this design is accomplishing those goals.

There are always tradeoffs on any design. IMO, the key is to optimize it for the intended application.

In a DH you would only close the DSV to take it out of your mouth (as opposed to a BOV), therefore it is not an issue to be lined up in the closed position.

There are a few other advantages of not having a lever, but more on that later.

Thanks

[Bryan]

Crowdfunding the new Argonaut DSV has begun! Please visit the website store for details and to jump in with the team for the big win!

[video]https://www.youtube.com/watch?v=-PDod3V ... load_owner[/video]

[Dave2]

Crowdfunding the new Argonaut DSV has begun!

Funding sent! Looking forward to production updates.

Dave

[Drado]

Exciting times! Looking forward to March!

[Bryan]

Thanks for the support gang! We are well on the way to making it happen.
I consider myself very fortunate to have such great friends and customers supporting the project.

[Bryan]

Luis and I in Cozumel a couple weeks ago, testing the new DSV on our Argonaut Krakens.

[luis]

Nice picture.


Here is my dive profile for the wreck dive (in the picture above), the Felipe Xicotenantl C-53.
All my dives were done with the prototype 3D printed mouthpieces.





Here is my dive profile for Devils Throat (La Garganta del Diablo), in Punta Sur.
It worked just as well in 140 ft as it did in 20 ft dives.

[uwstlth]

Brian mentioned some manufactures and retailers are selling DSVs for outrageous pricing- and he's right! Really, it's sick to see. One such manufacturer is well known in the RB community for having pricing based on a King's Ransom and crappy customer service, I stumbled across a few GoPro housings this guy is selling and just about barfed my coffee up when I saw the pricing, I got the GoPro itself camera for less:

http://www.golemgear.com/p-636-golem-go ... -back.aspx

So, with that I say Brian's pricing is much more in-line with reality. Just another POV.

[Pedro]

Brian mentioned some manufactures and retailers are selling DSVs for outrageous pricing- and he's right! Really, it's sick to see. One such manufacturer is well known in the RB community for having pricing based on a King's Ransom and crappy customer service, I stumbled across a few GoPro housings this guy is selling and just about barfed my coffee up when I saw the pricing, I got the GoPro itself camera for less:

http://www.golemgear.com/p-636-golem-go ... -back.aspx

So, with that I say Brian's pricing is much more in-line with reality. Just another POV.

To be fair, pretty much all aluminum housings are WAY more expensive than the cameras they house. This one for example:
http://www.bhphotovideo.com/bnh/control ... &A=details
is also rated to very deep depths and the price is not nicer. If you browse through DSLR housings your wallet will start crying and the credit card will flee in terror.

That being said, I'm not familiar with DSV prices. All I know is that VDH's looks good and seems to do exactly what I need for a price that won't break the bank. Couldn't ask for more!


Edit: except that housing is not made of aluminum, but anyway the point still stands. High quality housings are unfortunately more expensive than the cameras.