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D420! How about that?
- Thread starter axxel57
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Wonder when they were made?
- Messages
- 17,586
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Oh boy do I want to get my hands on one....
- Messages
- 17,586
- Reaction score
- 9,842
- Location
- Somewhere between here and there
- # of dives
- 2500 - 4999
I'm champing at the bit for two, I asked again today and was told they are unlikely to be sold separately for at least 6 months.
Looks like we'll have to wait a bit longer. I'm ok with that as it gives Rob time to put them through their paces. That's two horsey similes (?) in one post.
When I was young the MK5 - 109 were made here, in Casarza Ligure (near Sestri Levante, Genoa).
I visited the factory, and I was trained servicing these units. It was 1977.
But soon later, SP launched the Pilot, and that was coming from US.
Form what I was told at the time, US manufacturing had much more QC problems than the Italian factory, and those Pilots, albeit being the best regulators of the time, were quite unstable and almost impossible to service.
Hence SP abandoned them quickly, and moved to their plastic clones (Air 1 and following) which again were manufactured here, and were much more stable and without problems of servicing.
To the point that several Pilots sold here were quickly modified, installing internal parts of Air1.
Thank you very much for your video . As you well know ( because you rebuilt mine ) the pilot to be in tune leaks 6 bubbles a minute . So I would have to agree that slight leakage would not faze myself . I believe Scubapro purposely de-tunes the D420 for reliability . My Pilot is a fa-nominal breathing reg but she is temperamental as hell . That's why my go to reg is the balanced 109 . She takes a licken and keeps on ticken . No servo or viva . But there is no doubt in my mind that when I send my pilots to you for service they are in very good hands as their performance attests to that .
My wife once told me I should have never left my job as an aerospace quality inspector because, "You're good at finding fault."Some guys are just SO picky!
Never-the-less, @rsingler your videos are very informative. Before I watched, I wondered what's the big deal about a new D model. In fact, at first I was disappointed to see SP removed the coaxial exhaust valve and moved it higher in the water column. While the advantage of the coaxial valve (zero CGF) was sacrificed, I would be willing to bet the overall work of breathing with the new and re-positioned exhaust valve has been reduced.
I think we need to recruit @Nemrod to do a work of breathing test on his bicycle contraption all hooked up to a plethora of hoses and gauges. I cannot find the page with his last WOB experiment, but it was certainly enlightening.
I wish there were a scale on this thing:
If the valve crack in the bottom right corner is -1.25", then each of the horizontal lines are 0.5". Since the CE tests are at depth, we have thick air contribution to Venturi, and might not see the shift to a positive ?0.25"? assist in shallow water like I think we're seeing here.
Can't wait to get it on the rotameter. If 1-2 cfm is an average heavy workload RMV, it'll be interesting to see what the magnehelic shows at 8-10 cfm. I'll have to defer to @Luis on this, because he knows all that Reynolds number stuff, but I gather there's a very rough correlation between 8-10 cfm at 1 atm (on my bench) and 2 cfm at 4-5 atm (>100 ft). If we see a similar drop in inspiratory flow resistance as we seem to see on this CE graph, that'll be very good news! From Regulator Savvy, that capability is all critically dependent on case design and Venturi flow. And Venturi flow is where the center-balanced poppet design excels.
I also think they've also added the expiratory boost in redesigning the exhaust tee, like they did when they went from the S600 to the S620Ti. See around 3:30 in this video:
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