D420! How about that?
- Thread starter axxel57
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Dang! I do want one..... (but have no interest in a MK25)
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I want two
I could live with my S600 as an octo.....
- Messages
- 17,268
- Reaction score
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- Location
- Somewhere between here and there
- # of dives
- 2500 - 4999
As you know Bob, I'm pathologically OCD, I need both my seconds to match.
How will you be able to dive the F8???
- Messages
- 17,268
- Reaction score
- 9,471
- Location
- Somewhere between here and there
- # of dives
- 2500 - 4999
I've just watched Rob's video-very nice. I like what one poster said, "the only thing better than ripping a new toy out of the box apart is watching someone else do it ."
Brave to do it "live" and well done.
Brave to do it "live" and well done.
Here is a link to Part II of the Unboxing videos. If you're not tired of me yet, you will be soon!!
This near-half-hour video drones on and on
about two cool aspects of the D420: minimum sealing pressure for the center-balanced poppet of the D420 (0.5 inches wc!!) and the relationship of Case Geometry Fault (CGF) to minimum cracking effort. The engineers among you will note that I cheated on demo'ing the cracking effort, by just using a magnehelic on screen instead of that gauge plus an IP gauge so you could see when it dropped. But I'm within 0.1"-0.2", and you'll get the picture. I didn't have the heart to redo it all when @couv pointed out the missing info, when I sent him my rough cuts. Some guys are just SO picky! 
While the D420 doesn't have a coaxial diaphragm/exhaust valve, it instead uses its CGF to make breathing in the standard diving position (looking down ~30 degrees) virtually effortless. Coupled with the ease of disassembly and service, this is looking to be one very cool regulator!
The last video in the series, currently under construction, is going to (finally!!) be a disassembly for you DIY guys, so you can get a look at the hard plastic knife edge. I think you'll be pleased! You'll see just how easy this reg will be to service, especially compared with the D400 scrotum.
We'll also put the reg on a flow bench, and use Pete Wolfinger's technique from Regulator Savvy to compare the output of this reg's center-balanced poppet, with an A700 using a classic S-wing poppet (where gas has to flow past the poppet and through the spring instead of right out the door).
Again, I think you'll see that all the enthusiasm for the D420 is not misplaced, and that the tradeoff from a coaxial exhaust valve to a more standard case has provided the best flow on the planet for the majority of diving positions. I am SO pleased by this reg, thus far!
When the manual is released in a few months, we'll see if all this speculation is borne out by the Scubapro official position. And during April's trip to Bonaire, I'll put three regs on the Mk25 (D400, D420, A700) and compare them (not that you can trust me). If there are other regs you think I should compare (I know, I know, "A shiny chrome Balanced Adjustable!"), I'll see if my baggage allowance will permit it.
This near-half-hour video drones on and on
about two cool aspects of the D420: minimum sealing pressure for the center-balanced poppet of the D420 (0.5 inches wc!!) and the relationship of Case Geometry Fault (CGF) to minimum cracking effort. The engineers among you will note that I cheated on demo'ing the cracking effort, by just using a magnehelic on screen instead of that gauge plus an IP gauge so you could see when it dropped. But I'm within 0.1"-0.2", and you'll get the picture. I didn't have the heart to redo it all when @couv pointed out the missing info, when I sent him my rough cuts. Some guys are just SO picky! While the D420 doesn't have a coaxial diaphragm/exhaust valve, it instead uses its CGF to make breathing in the standard diving position (looking down ~30 degrees) virtually effortless. Coupled with the ease of disassembly and service, this is looking to be one very cool regulator!
The last video in the series, currently under construction, is going to (finally!!) be a disassembly for you DIY guys, so you can get a look at the hard plastic knife edge. I think you'll be pleased! You'll see just how easy this reg will be to service, especially compared with the D400 scrotum.
We'll also put the reg on a flow bench, and use Pete Wolfinger's technique from Regulator Savvy to compare the output of this reg's center-balanced poppet, with an A700 using a classic S-wing poppet (where gas has to flow past the poppet and through the spring instead of right out the door).
Again, I think you'll see that all the enthusiasm for the D420 is not misplaced, and that the tradeoff from a coaxial exhaust valve to a more standard case has provided the best flow on the planet for the majority of diving positions. I am SO pleased by this reg, thus far!
When the manual is released in a few months, we'll see if all this speculation is borne out by the Scubapro official position. And during April's trip to Bonaire, I'll put three regs on the Mk25 (D400, D420, A700) and compare them (not that you can trust me). If there are other regs you think I should compare (I know, I know, "A shiny chrome Balanced Adjustable!"), I'll see if my baggage allowance will permit it.
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