I went back and forth with Luis for a long time as I wanted to stick with the DRAGER DSV design because it was so simple and had been in use for so long. As Luis pointed out there were a few things about the DRAGER design that were not so great, paramount being the angle of the mouthpiece while in use. The DRAGER comes straight out just like the US Divers original double hose mouthpiece and puts much more strain on the teeth and jaw muscles when using it. I immediately gave up the DRAGER style design idea after diving with one for a week in Bonaire....OUCH.
The manufacturing process has been strained since day one but I do not have an real answer as to why. The manufacture I chose was given 3D files and a very detailed description with pictures and dimensions as to what was required for the project and ample time to ask questions before they gave me a price to make it.....
What I believe occurred is they tried to make all the parts by molding. This was evident by the first sample pieces. If they could make all the parts by molding the process would be fast and much more profitable for them.
After the critique of the first samples we established that secondary machining steps would be required to get it right. The maufacturer machined the wagon wheel grooves and that was about it. The second sample parts had fantastic wagon wheel and the diverter was good but the rest was garbage. The inner tube was not concentric, the outer tube lacked the correct chamfering around the outlet and the groove for the center O-ring was not stable.
Once again I allowed them time to come up with a "gasket" to use in place of an O-ring to seal the outlet opening. They struggled with this for way longer than I should have allowed before deciding that their idea was not going to work.
The only solution was to have two additional machining steps to produce the precise tolerances needed for the center outlet opening O ring and the chamfering of the outlet of the outer tube. If you are still reading this......They had to fill in sections of the mold so material could be left to machine. The center outlet O-ring groove was filled in the mold and the step was done by machining after it came out of the mold. The outer tubes inner diameter was filled in slightly so they could machine the center bore for precise alignment......Machining the O ring groove on a cylindrical shape has been challenging for them to say the least. With machining steps comes finishing steps and there has been an ongoing disagreement over who should bear the cost of all these extra steps added to the process.
The last sample parts that Luis and I have could be used for diving with some minor hand finish work as Luis said........I need to keep this part to a minimum as I don't have time to do it nor am I going to pay for a finished product that I have to tinker with to make it 100%. If I were only making a dozen of them it really would not be a big deal. I expect these to be in high demand so I ordered several hundred and doing fit and finish on all of them is something I have no desire to do considering I'll have to assemble and test them all anyway!
I think we are very close and if the results from diving with the samples I think there will still be time for everyone to get some late summer/early fall diving done with the new DSV.
Picture below shows the mouthpiece sans a couple of screws I don't have yet.
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Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB