User avatar
luis
VDH Moderator
Posts: 1608
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Phoenix HPR second stage

Sat Mar 17, 2012 5:25 pm

Phoenix HPR Royal second stage

Talking to Bryan he mentioned that the new Phoenix HPR (High Performance Regulator) will be available very soon. The parts have been ordered and he will have it available long before Sand Dog.

Therefore, he suggested that it is time to explain and show the new second stage.

The reason for not showing more from the beginning is because the design looks very simple and very similar to many other basic demand valve second stages. A poor reproduction can be easily copied, but the performance is in the details.

At first glance some may say that it looks a lot like a Trieste second stage or maybe the second stage on some single hose regulator. The answer is that the details are very different from a Trieste, but it does take many refinements used on some of the better designed (but simple) single hose second stages.

I have considered many times how to make a balanced second stage for a DH, but with the mechanical advantage of the large diaphragm I have concluded that there is no need for it. The trick is in keeping friction down in the right places, take advantage of good mechanical lever, and have good control of venturi effect.

_______________________________________________________________________________

But before I talk about the Phoenix HPR, I want to start by going over the original RAM second stage as shown in the picture below.

Through the years we have all made some modifications to the original second stage to make more user-friendly and improve performance: we don’t bend the top of the horseshoe support hinges anymore, we don’t stake the nut to lock it anymore, we may file the edges of the hinges to smooth out all the contact point, etc. You can even see that I file notches on the horseshoe to allow better access to the hinge support screws.

In addition we spend some time aligning the horseshoe hinge supports with the horseshoe and the seat carrier in order to reduce any binding or friction. We then adjust the lever height and when we are happy with it we lock the nut with glue or nail polish or similar. And we hope that we don’t need to change the adjustment.

Then when we place the diaphragm we need to carefully align it so that the high spot on the curved tabs are just over the contact point on the horseshoe. But, that is not perfect, because the horseshoe is not perfectly lined with the center… but it is close.

Anyway you get the point.

When we are done some of them perform extremely well, but not all… and we go back and tinker with it some more.

The hinge supports just have too many contact points with the horseshoe that have to play together well to reduce friction and avoid any binding. The forces are hard to feel because that are very low, but that is the magnitude of the forces we are dealing with.


Image

__________________________________________________________________________

So now about the new second stage, what makes it high performance and very used friendly.

The unit is first of all simple. It is a module that can be preassemble and then installed. The lever height is easily adjusted after installation, and it may never need to be adjustment again.

Instead of several parts that need to be aligned, the lever is captured, but with plenty of play to avoid binding and minimize friction. The contact points of the lever are carefully controlled and the module is self contained. The lever has very good mechanical advantage with a very simple prying action on to specifically selected contact/ fulcrum points.

The second stage uses the same basic diaphragm used with single stage regulators. The need for special contact tabs is eliminated. There is no need to align any special points on the diaphragm with the lever. The friction is extremely low with the use of low friction plastic contact points at the tip of the lever. I have more information on this later.

The cracking effort of the regulator (not including the hose loop, which should be low) I have measure it to be consistently around 0.5 inWC. The best part is not how well it performs, but how consistently it performs well.

The venturi flow effect is very powerful and easily adjustable. I have been experimenting a lot with venturi effect on single stage and two stage regulators and have determine a good compromise between too much and too little venturi. But I still designed it to be adjustable so those who like to tinker can play with ultimate performance.

The venturi adjustment is based on the amount of bleed air allowed into the can to reduce the amount of vacuum generated by the high speed flow down the horn.

If too much bleed air is blocked, the venturi effect is so strong that the harder you inhale the more air is delivered and therefore it is wasted out the exhaust.


So not only not only does it has superb performance, but it is very simple, which makes it extremely reliable and consistent, and it is very easy to service.

The use of a diaphragm without tabs makes it very easy and quick to open and close the case (with a band clamp) for easy cleaning and service.

______________________________________________________________________

To make or adjust a regulator to breathe easier that this, it becomes basically impractical. Anything that would have a lower cracking effort (less than 0.5 inWC) will tend to free flow in any position where the exhaust is just above the diaphragm. I can adjust it to even lower cracking effort, but it is not recommended.

At the same time adjusting the venturi too high will also have a tendency to deliver more air than needed (and bypassing out the exhaust) when inhaling hard or at depth when air density increases. Again, this second stage can be easily adjusted to perform like that, but it is not practical.

I do not have a work-of-breathing test machine, but based on the instrumentation I have and 40 years of tuning regulators I find this to be the best DH regulator I have worked with.

As with any double hose, in order to get the best performance, it is imperative to place it in the correct location. That is were the VDH back plate comes in.

IMHO, the combination of the Phoenix HPR Royal and the VDH back plate will deliver the over all best performance possible for any open circuit Scuba system. Some performance criteria’s may be subjective, but I do feel that this combination will outperform even the best breathing regulator that is available.

____________________________________________________________________

Here are some pictures. These are just prototype units so they are a bit rough.

The plastic rivets in the prototype have the correct top shape, but the back is not the finished product.

The screws that you see on the side are basically just to keep the assembly from unscrewing. The spring tension can be adjusted by unscrewing the assembly every 180 degrees, but with the mechanical advantage and low friction of this lever, I have not seen a need.

Only one screw is needed, but I think it looks better with both:

Image


Image


Image



Here is a picture of the second stage module pre-assembled before installation.
I will be showing more pictures on the best way to install it and adjust it later.

Image
Luis

Buceador con escafandra autónoma clásica.

User avatar
luis
VDH Moderator
Posts: 1608
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: Phoenix HPR second stage

Sat Mar 17, 2012 5:54 pm

Infinitely adjustable venturi:

The screws can be replaced with these screws with shoulder washes to block some of the air bleed in order to obtain higher venturi effect.

Here is shown with both bleed air ports open for normal venturi performance:

Image

Image


Here one of the bleed air ports is mostly blocked to provide higher venturi effect.

Image


And here both bleed air ports are blocked. This will cause a venturi effect above the need of most divers.

Image


If you notice I cut the shoulder washers at an angle so it is actually possible to partially block either bleed air port.
Luis

Buceador con escafandra autónoma clásica.

User avatar
Bryan
Plank Owner
Posts: 5264
Joined: Fri Jun 24, 2005 11:40 am
First Name: Bryan
Location: Wesley Chapel Florida
Contact: Website

Re: Phoenix HPR second stage

Sat Mar 17, 2012 6:22 pm

A little more detail can be seen here.... I have cycled one of the prototypes almost 4000 times with zero movement or need for re-adjustment.

Image
Image
Image
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

swimjim
Master Diver
Posts: 1566
Joined: Thu Mar 23, 2006 12:28 am
First Name: Jim
Location: Belgium WI

Re: Phoenix HPR second stage

Sat Mar 17, 2012 7:08 pm

In two weeks I can hit the water again. I would really love to test this. Looks pretty sweet!

jim

User avatar
luis
VDH Moderator
Posts: 1608
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: Phoenix HPR second stage

Sat Mar 17, 2012 7:15 pm

I have done a lot of diving up here in Maine and in the Caribbean with one of the prototypes, and it has performed great.

For this project I got some help with computer modeling and prototype fabrication. It has been a good group effort.

Thanks
Luis

Buceador con escafandra autónoma clásica.

User avatar
2THDIVR
Master Diver
Posts: 104
Joined: Sat Jan 02, 2010 4:01 pm
First Name: Scott
Location: Venice,FL

Re: Phoenix HPR second stage

Sat Mar 17, 2012 7:20 pm

Very nice. I'm definitely going to need 1 or 2 or maybe even 3

User avatar
cloudflint
Skin Diver
Posts: 47
Joined: Sat Oct 09, 2010 3:49 pm
First Name: jake
Location: Scotland
Contact: Website

Re: Phoenix HPR second stage

Sat Mar 17, 2012 7:58 pm

It looks like a very simple design and as with all things which appear incredibly simple I suspect a huge amount of thought, planning and experimentation has been put into it, very nice! :)

User avatar
Herman
VDH Moderator
Posts: 1264
Joined: Thu Oct 25, 2007 1:45 pm
Location: Raleigh NC

Re: Phoenix HPR second stage

Sat Mar 17, 2012 8:14 pm

cloudflint wrote:It looks like a very simple design and as with all things which appear incredibly simple I suspect a huge amount of thought, planning and experimentation has been put into it, very nice! :)
I can only guess the hours Luis spent on the project but I know for fact he was on the phone and email quite a bit. :) This is not only just the nozzle but the lever and LP seat holder are new as well. There is a lot of time and energy spent to produce a product like this....and a lot of screwed up prototypes - I have a bag full of them. :)
I really hope the double hose community enjoys the nozzle and appreciates the improvement it makes to the double hose reg. It has been fun doing the prototypes, I am glad I got to help with the project.

What are we going to do next Luis??
Herman

User avatar
Drado
Master Diver
Posts: 646
Joined: Mon Feb 07, 2011 6:11 am
First Name: Eduardo
Location: Manila, Philippines

Re: Phoenix HPR second stage

Sat Mar 17, 2012 8:38 pm

Only one word for this: Brilliant! :D
Herman wrote: I really hope the double hose community enjoys the nozzle and appreciates the improvement it makes to the double hose reg.
I'm very sure we'll all enjoy this!
_______________________________
Ed

User avatar
Herman
VDH Moderator
Posts: 1264
Joined: Thu Oct 25, 2007 1:45 pm
Location: Raleigh NC

Re: Phoenix HPR second stage

Sat Mar 17, 2012 8:52 pm

Bryan, a question. I know it may be a little early for details but I was wondering, are the nozzles going to be sold as a kit - all necessary parts in one package- or is it going to be available as individual parts?
Herman

User avatar
EHowe
Master Diver
Posts: 200
Joined: Sun Aug 28, 2011 2:59 pm
First Name: Edward
Location: Chicago

Re: Phoenix HPR second stage

Sat Mar 17, 2012 9:07 pm

Very cool. How much $$? And how many available on the 1st run?

User avatar
Drado
Master Diver
Posts: 646
Joined: Mon Feb 07, 2011 6:11 am
First Name: Eduardo
Location: Manila, Philippines

Re: Phoenix HPR second stage

Sat Mar 17, 2012 10:21 pm

Quick question on the diaphragm needed: If I rotate the current 2 stage diaphragm 90 degrees so the tabs are out of the way, will it work just as well - or will the coefficient of friction between the SS plate in the 2 stage diaphragm against the plastic nubbins on the lever as compared to the plastic plate in the single stage diaphragm be higher?

Additionally, when adjusting lever height, would getting the height right be similar to using Bryan's Mistral lever height tool?

(I know I'm getting way ahead of myself - but I'm just excited! :D )
_______________________________
Ed

User avatar
8dust
Master Diver
Posts: 548
Joined: Wed Aug 05, 2009 11:39 am
Location: Nashville's North Shore

Re: Phoenix HPR second stage

Sat Mar 17, 2012 10:44 pm

Well done fellows! :D

Looking forward to having one.

Good questions Ed. I'll add a +1.
Freddo
NAVED member #201

User avatar
luis
VDH Moderator
Posts: 1608
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: Phoenix HPR second stage

Sat Mar 17, 2012 10:50 pm

Drado wrote:Quick question on the diaphragm needed: If I rotate the current 2 stage diaphragm 90 degrees so the tabs are out of the way, will it work just as well - or will the coefficient of friction between the SS plate in the 2 stage diaphragm against the plastic nubbins on the lever as compared to the plastic plate in the single stage diaphragm be higher?
I knew it wasn’t going to be too long before someone asked that… and I should have know (well I actually suspected) that it would be you. :roll: :wink: :lol:

luis wrote: The second stage uses the same basic diaphragm used with single stage regulators. The need for special contact tabs is eliminated. There is no need to align any special points on the diaphragm with the lever. The friction is extremely low with the use of low friction plastic contact points at the tip of the lever. I have more information on this later.
I guess this is later…

OK here is the deal. You could use the metal plate diaphragm by bending the tabs out of the way; the new lever is actually narrower than the tabs. But...

The problem is that the coefficient of friction as I have measure it is going to be too low. Yes you read it right, too low. With the plastic (nylon) tips on the prototypes lever the cracking suction was well below the 0.5 inWC and I could not increase it by lowering the IP (and the second stage spring pressure was at its max).

I will test it all again with all the production parts, but so far the prototypes have all been very consistent in its performance. And it just worked best with the synthetic diaphragm disc.

Having too little friction sounds like it should never be a problem, but it would be if it causes free flows and that is what I was starting to encounter.


The other reason why I prefer the synthetic plate is because it is substantially lighter than the stainless steel plate. The weight of the plate was also affecting the performance and the actuation of the demand valve. Just the plain static weight at times was at the edge of actuating the lever (when the regulator was with the diaphragm facing up). The regulator should perform the same facing in all directions.
Luis

Buceador con escafandra autónoma clásica.

User avatar
luis
VDH Moderator
Posts: 1608
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: Phoenix HPR second stage

Sat Mar 17, 2012 11:03 pm

Drado wrote:
Additionally, when adjusting lever height, would getting the height right be similar to using Bryan's Mistral lever height tool?
Adjusting lever height is not at all critical. With the super flexible silicone diaphragms this regulator doesn’t care if there is a small gap from the lever to the diaphragm.

I actually like leaving a small gap to accommodate any potential seat compression.

I have taken plenty of vacuum measurements and notice I while back that with the mouthpiece valves in place the vacuum inside the can seldom returns totally back to zero after taking a breath. The vacuum stays around 0.2 inWC. That is just enough to keep the diaphragm against the lever waiting for the suction from the next breath to activate the demand valve again.

Drado wrote: (I know I'm getting way ahead of myself - but I'm just excited! :D )
Yes…
:roll: :lol:
Luis

Buceador con escafandra autónoma clásica.

Return to “Phoenix and Argonaut Specialty Area”

Who is online

Users browsing this forum: No registered users and 2 guests