Twin Pipe (loop) Snorkel (DIY)

[artiz]

I didn't get this twin-pipe snorkel idea at first (see my response on this thread "A better snorkel for spearfishing", http://forums.deeperblue.com/threads/a-better-snorkel-for-spearfishing.99138/ ). However, I just fixed the video link on the other thread referenced in the original post: http://forums.deeperblue.com/threads/very-cool-diy-dual-tube-snorkel-for-about-6.97796/ and watched it. Ok I am beginning to see some potential advantages:

1. Reduces "Salt fog" - whatever that is. (BTW How does it achieve that?)
2. Clean purging - don't see why that would be but if it does that would indeed be a benefit. I would have expected that it might be worse, for example: might water sometimes be purged from only one of the 2 pipes? If so, you'd end up with water re-filling the mouth-piece
3. Hydrodynamic (streamline)
4. You can make it yourself, cheaply - or 3-D print it (brilliant!).
5. Probably less cumbersome in use that a normal mask-mounted snorkel. No need to remove & hold (for those who prefer to remove the snorkel when diving) - just drop it from the mouth.

Ok, I beginning to see some potential. Anybody using one for spearfishing regulary?

My assumption regarding salt fog is that it is created/formed when you purge/suck air hard... perhaps you tend to breathe back in a certain amount of salt laden steam/mist/breath back through the snorkel... but I'm afraid I'm actually clueless?
Anything nearer to a cleaner purge was definitely one of my main objectives... it has always irritated me when water is gurgling/whistling around in my snorkel; noise/stealth/over clearing etc... also still being a smoker doesn't help of course.
It feels easier/more natural perhaps to clear through 2 smaller (9.5mm) holes... you get more purge for your blow as it were... and with that added lung power also comes a far quieter, more stealthy and controlled purge... I'm not blowing like a humpback... which is a definite improvement! Also if you keep the (non-valve) snorkel in when diving you can rise slowly (still looking down) to the surface exhaling (breath allowing) just enough so that when you break the surface your purge can be minimised... more/better purge control is the biggest advantage so far for me! I definitely preferred the valved versions though!
Trying all 3 out in a pool was a revelation but not much of a test regarding waves/chop/weather etc.
I tend to keep my snorkel in mostly so another clear advantage is having the option to just open my mouth (when/if I so choose) rather than spit it out... which I always found uncomfortable doing. Also with it dropping down under my chin I can't think of a better place for a snorkel/mouthpiece regarding both convenience and hydrodynamics... its nice and small too.

I have to come clean though work has kept me out this year so the week after next I'm off testing all 3 in the wild at last.... regularly used no... but hopefully about to be... thanks for your comments Mr X

 

[artiz]

Apologies for photo quality

I've used a new IST donor snorkel for this version but I reckon you could do this with most snorkels that have those flexible/silicone extensions. I've used more of the donor snorkel as well as using both 3D printed mouthpieces/connectors/regulators... the first being the valved version (into my mouth) and the second (no valve) as the three way connector (at the back) for the twin pipes as well as the donor snorkels flexible/universal silicone connector which in turn connects to the longer plastic part of the snorkel which is mounted on the open style mask straps (Cressi F1)... on top/back of the head using the strap retainer already attached to the donor plastic pipe... together with an additional rubber/silicone snorkel loop attached to the lower mask strap.
Nothing from the donor snorkel is either cut/modified or destroyed this time but the all important 25mm, one way valve gasket (mushroom) from the IST donor snorkel will/may not survive being taken back out from the 3D printed mouthpiece... once you've fitted it... the 20mm ones I got from the states are useless.
Just about everything is easily adjustable to suit preference, comfort, snorkel height, optimum pipe bend/length for automatically popping out (by opening your mouth)/not popping out... even the inner diameter of the pipes can be anything between 11mm and roughly 15-16mm for added airflow... not forgetting the inner diameter of the 3D printed regulators are 2 x 9.5mm! It's also very easy to take apart and put back together again... the downside is that this version is not under £10... its actually quite expensive and still untried... until next week anyway... It does seem like a lot of pipe to fill up/purge through, making that one way valve even more important? Nothing to stop trying 2 valved mouthpieces or even better an appropriate donor dry snorkel perhaps (top valve)? Doesn't look particularly 'streamline' though... might even mess with my mask fit/stability... I'll let you know?

1. Donor snorkel (new) £11.95
2. Hose (new) £3.76
3. 2x 3D printed mouthpieces (iMaterialise.com) £46.51 (inc 10% designer fee, tax & delivery)
4. Snorkel loop £2.25

P.S. With a budget universal/correctly fitting top valve/dry donor snorkel... (£8.98)

 

[REVAN]

I didn't get this twin-pipe snorkel idea at first (see my response on this thread "A better snorkel for spearfishing", http://forums.deeperblue.com/threads/a-better-snorkel-for-spearfishing.99138/ ). However, I just fixed the video link on the other thread referenced in the original post: http://forums.deeperblue.com/threads/very-cool-diy-dual-tube-snorkel-for-about-6.97796/ and watched it. Ok I am beginning to see some potential advantages:

1. Reduces "Salt fog" - whatever that is. (BTW How does it achieve that?)
2. Clean purging - don't see why that would be but if it does that would indeed be a benefit. I would have expected that it might be worse, for example: might water sometimes be purged from only one of the 2 pipes? If so, you'd end up with water re-filling the mouth-piece
3. Hydrodynamic (streamline)
4. You can make it yourself, cheaply - or 3-D print it (brilliant!).
5. Probably less cumbersome in use that a normal mask-mounted snorkel. No need to remove & hold (for those who prefer to remove the snorkel when diving) - just drop it from the mouth.

Ok, I beginning to see some potential. Anybody using one for spearfishing regulary? Anybody tried one?

It is awesome to see that people are actually building loop-snorkels! It feels like I have made a difference in the world.

I thought I'd say a few things about the concept that would clear up some concerns by Mr.X that are probably not unique to him. Regarding comment #2, the scenario you posed will not happen and here is why:

In the dynamics of a purge, equal pressure in the 2 tubes will tend to accelerate the water out the tubes at equal rates. Water has mass, and once it is moving it will want to keep moving. However, if we use a hypothetical finger to temporarily block one tube and stop its purge, all the purge air would have to flow out the other tube. The air normally conveyed by 2 tubes is restricted to 1, so the velocity through the open tube will be doubled. The resistance to the flow is proportional to the velocity squared. A doubling of the velocity will require the pressure rise at the source to increase by a factor of 4, which is more than enough pressure to accelerate the water in the other tube once the hypothetical finger is removed to unblock the snorkel. So, even if they don't purge together, as long as the tubes are both unrestricted at some point during the purge, they must both purge. This is true as long as the tube diameters are not too large. If the tubes are too large the resistance of one tube during purge will have a lower pressure rise than the hydrostatic pressure of the water column in the tube, and then there can be a problem.

So, the trick to getting this snorkel to work correctly is to choose a tube diameter that feels resistive to breathing through only one tube, but is easy to breath through when there are two. It also helps to have a small enough tube diameter with a low reynolds number for the water column, that the water in the tube remains laminar during the purge so that it doesn't leave water residue behind in the tube. Ideally, we want to see two laminar columns of water being quietly ejected from the tubes. These elements combined can make for a very clean purging snorkel.

Cheers,
Ron

PS - The snorkel pictured above doesn't look like it will work very well. Have you tried it yet?

 

[artiz]

PS - The snorkel pictured above doesn't look like it will work very well. Have you tried it yet?

Ron, thanks for the post,

Yep, they all work to varying degrees of satisfaction, preference and modus operandi etc... but the one that most appeals to me personally as a good all-rounder is the 3D printed regulator with purge valve and no bite (bridged) mouthpiece... attached to straight thru 10mm inner diameter pipes cut to my personal height preference. It's simple, cost effective and comfortable. It's also definitely helped my particular style of basic hunting which is close in and species specific. It has allowed me to become more stealthy and in particular more quite when I have spotted my quarry but then need to resurface and purge. There's also less residue after a purge as you rightly point out above which cuts out all that extra huffing and puffing when trying to clear. I have far more all round snorkel control now... and I absolutely love it. The convenience of being able to pull your mask off and let it hang from your loop snorkel when you pull yourself out of the water is not to be underestimated either! With the added feature/option of allowing it to pop out of my mouth using the natural bend in the pipes it feels safer too when I'm pushing it depth wise... although I have to say serious apnea is not high on my agenda these days... mainly cos I'm getting on a bit. Your orginal idea was a cracking one Ron so a very, very sincere and personal thanks from me... I'm not sure anyone else is that interested though... but if your happy why bother changing I suppose... other than it's ten times better for spearfishing than a conventional snorkel?

Respect & Regards

 

[REVAN]

Perhaps it is time to really develop this thing. I like your idea for the rapid prototyping. In the time since posting the original video for the snorkel, I have invested thousands of dollars in a sophisticated 3D CAD suite. Lets collaborate on an update and see if we can make a really well refined design. Can you send my a solid model of your favorite model and let me know what you would do differently on a revised design? If you actually like the non-printed design better, can you show a picture so I know which configuration you are referring to?

 

[artiz]

Ron... this is the pipe set up I'm talking about which is similar to your mk 1 original... but fitted with the 3D printed regulators...(http://i.materialise.com/shop/search?query=snorkel) They make everything so much more simple and configurable. This is where I had my designs made and posted to me in the UK so I'm sure they can post to you in the States... both the version with valve and without work well but I tend to favour (very slightly) the purge valve version... but only cos I'm used to the same in a conventional snorkel. Over the summer I've been testing all of my configurations so I tend to keep changing my mind cos I haven't had anyone else testing to get a second opinion! I also get a bit distracted cos I'm hunting of course. Makes it all a bit haphazard I'm afraid. I do actually have an M.Sc. in Interaction Design so I should be more professional regarding my research and iterations but its all been a bit of fun and taking it serious wasn't on the agenda... until now!
I certainly know what I would do to make considerable improvements though... especially with a decent 3D software package like Solidworks which I already have experience with from work... although the free version of Google Sketchup has been very useful. I'll send a private message with my email address and we can discuss from there!

 

[REVAN]

The things I can think of that I would do differently is to use a thinner wall tube that is more flexible, and design more ergonomic bite buttons. My current design requires the thicker wall tubing to get it to fit the holes in the mouthpiece. If I'm making a custom mouthpiece, that will not be an issue. The other thing I always wanted to do was make it easier to attach and detach from the mask. My current setup has 3 snorkel keepers that need to be dealt with.

 

[artiz]

The things I can think of that I would do differently is to use a thinner wall tube that is more flexible, and design more ergonomic bite buttons. My current design requires the thicker wall tubing to get it to fit the holes in the mouthpiece. If I'm making a custom mouthpiece, that will not be an issue. The other thing I always wanted to do was make it easier to attach and detach from the mask. My current setup has 3 snorkel keepers that need to be dealt with.

For me it seems easier to leave it attached to my mask... which as a unit is also more convenient... two less pieces of equipment to carry or worry about when out of the water cos its hanging round your neck... although some kind of quick release makes sense too... strap attachments from my donor snorkels have also helped with that problem.
Ergonomics all round will be an important aspect of most of the improvements I would like to make...

I have emailed your smithaerospace hotmail address by the way...

 

[artiz]

This is my latest 3D printable Twin Pipe Snorkel regulator with dimensions... 'strait thru' type model... been working on this one for a while in Sketchup... now I've nailed it. I've managed to get rid of the void in the regulator so that I am now purging straight through... even more control/stealth. Standard 20mm x 30mm mouthpiece fitting. You've got a wider choice with your pipe ID's from 9mm/9.5mm (3/8") upwards to probably 13-14mm... tighter fit is better and reinforced hose is worth considering... trial and error needed here for your own personal requirements! I've ordered mine and should get it within a couple of weeks... shiny black plastic this time but if its good then a stainless steel copy will at last be mine.
I'll post up some photos and the link to imaterialise when my latest prototype arrives.

​

I'm also trying to improve on how I attach the TP snorkel to my mask straps at the back... I found one of these hose seperator clamps which helps to keep the pipes in the optimum position for height (out of the water), bend (for mouthpiece to pop out) and comfort/convenience...

so I'm now trying to attach it to a quick release snorkel clip...

Any further suggestions/ideas/solutions are much welcomed...

P.S. Suitable lower profile hose link...

 

[artiz]

Sorry... last one with a bit more style...

​

All the dimensions of the regulator flow or purge can be personalised to whatever suits individual differences or even sporting subleties regarding freediving, spearfishing, underwater sports/water polo etc. You can even pull it out of the mouthpiece even when/if it's in someones clenched teeth!

 

[artiz]

Keeping the mask attachment on the top of the head DIY I've just used snorkel clips from old/donor snorkels. The important part is the hose separator clamp pictured (big) above which secures the twin pipes in the exact position required (pointing upwards/backwards/correct height)... the one I have used is a 13mm (£3.89) to match the new 10-13mm hose I am using for the 'strait thru' regulator configuration... you could use two hose separator clip/clamps... although it seems better for the top one to be adjustable along the pipes! Attachment to the suitably cut down snorkel clip is a simple self tapping screw into an appropriately drilled hole through the clip and into the hose clamp. Whatever clips you use... the more movement they give... the better working adjustments you have. Leave your pipes long...ish and then cut to size after testing. If you are safety concious then a bit of dayglow, waterproof tape at the top could finish it off.

​

 

[Fredd]

Sorry... last one with a bit more style...

Hi artiz, did this final piece make it to the printers? Did you have one made please. I'd really like to order/have one made. It's
a great design.

Edit: I followed your link and found it at imaterialise. Thank You

 

[Jackin]

Hi all,

good work everybody, especially artiz (and Ron too of course).
Last month I try to make my own, inspired by original Rons design. Few days back I found this thread - you made me happy for this development lives.

I need an advice - which tubes are the best for loop snorkel:
1) XSPC HighFlex Hose 16/10mm
2) Tygon Norprene Tubing 12.7/9.5mm Black
3) Tygon Norprene Tubing 15.9/9.6mm Black
4) Tygon R3400 Tubing 12.7/9.5mm Black

Common PVC hose has low flex and it makes all design with huge diameter around your head. I want to use silicon or others.
Tygon Norprene is very flexible, mabye too - in computer water cooling is normal to use some support springs to eliminate wrap.
Because I have only normal silicone transparent tubes (only for prototype, it is rests from ma own computers cooling) and no experience with tygon and xspc tubes, I am asking for advice what to choose. Price is not cheap (some of them for over 10USD/m in our country from local shop) and I do not try all of them by my own. I am looking for tubes with minimal wrapping and optimal flex - for this application.

On picture is my own loop snorkel derivative (in my country we do not have something familiar with rons T-piece, it was hard to held original concept), there is few imperfection:
- long narrow tubes fittings (it makes wide front design few centimeters from face on both sides)
- solid PVC tubes (difficult to get mask on and to split mouthpiece off, but I think solid tubes is better on the other end to keep outlet at better position, maybe I am wrong - not enough tested by my own)
- only 10mm inlet for mouthpiece (I am waiting for sugru form UK, again - in our country sugru sale is prohibited by byrocracy), this is total disaster, but once a week this imperfection help to test another aspects of design (tubes lenght and position on a head exactly)
- no walve
I upload this only for Rons or other curiosity, what can arise from one idea. The mask is Technisub Micromask and it is in revert position.
Tubes are mix of PVC and silicone. Mouthpiece is from my old valve snorkel (I dont want to destroy it). T-piece I found over one year only by mistake at near shop with homeware, better I am unable to find.

For future:
I like Apneaddict concept (simple and fast to build for the start).
Also I want valve version of last artiz 3D model. Maybe with more angled house fittings. I think there is no need for fittings to be in round proportion. If fittings clutch, lets say - 90 to 120 degrees - it mybe will be enough and eliminate wide look and tubes wrapping. But I have very narrow face. Maybe it is not for everyone. Also I prefer short design, not bulky or long valve. More material and bigger 3D design, more fatique for my mouth I think. Replacable mouthpiece I want too.

After I get sugru and choose right housing, I try apneaddict design or combine it with artiz first version (not replacable mouthpiece, but with valve - it will be very short design). I really need it for summer time at the lastest.
Next will be 3D model by artiz (not totally cheap for one try) - Artiz, is there any chance to combine it with valve (drill and glue something) ? Or you make another 3D valve model ?

 

[REVAN]

1. Reduces "Salt fog" - whatever that is. (BTW How does it achieve that?)
2. Clean purging - don't see why that would be but if it does that would indeed be a benefit. I would have expected that it might be worse, for example: might water sometimes be purged from only one of the 2 pipes? If so, you'd end up with water re-filling the mouth-piece

I've been away from this issue for a while. I've been working on other projects, but maybe time to think more about doing something with this.... On the above quote:

I dive in the Northern half of the Sea or Cortez. It has a high salt content (as does the Mediterranean in many places). I would often have the issue where some seawater would remain trapped in the snorkel. As I breath through the snorkel, that water would tend to aerosol and the droplets containing the salt would coat my throat in a fog of salt. Over time it could get very uncomfortable, even painful when swallowing.

The idea with the twin tubes is to use a small enough diameter tube to get a low Reynolds Number water flow in the tube during the purge that the water in the snorkel slides out in a smooth laminar jet. When this is achieved, there is basically no seawater residue left in the tube. The water acts like a single object and uses its own viscosity to pull the water that wants to stick to the tube along with it. It self cleans in a way. My snorkel purges very clean, with the only water getting left behind being the water that gets stuck in the joint between the tubes and the mouthpiece. No need for a snorkel valve, because there is nothing left behind to push out through it.

The twin tubes are not there to make it look cool. They are there because getting the laminar jet requires a small enough diameter tube that the breathing resistance becomes an issue. Using two tubes provides an acceptable level of breathing resistance, but it also made the snorkel more practical by keeping it constrained like a necklace when you have the mouthpiece free and clear from your mouth. For scuba divers, it is an additional benefit of the snorkel acting as an extra mask restraint that your mask will not get lost if something knocks it off your head (less need to carry a spare mask on technical dives). So, there are other secondary benefits to the dual tube design beyond the original objective of a laminar purge.

Can it introduce a new issue where one tube clears, but not the other? Not really! When one tube clears before the other, only one tube is open and flowing. That means that during the purge, there will be twice the flow attempting to exit the one open tube, or actually twice the velocity of flow. Resistance to the flow goes up as a square of the flow velocity, so there is a 4x pressure rise for twice the flow speed. The stable configuration is for the unpurged tube to also clear, opening both tubes and lowering the back pressure by a factor of 4 in the process. It just works!

 

[REVAN]

The idea with the twin tubes is to use a small enough diameter tube to get a low Reynolds Number water flow in the tube during the purge that the water in the snorkel slides out in a smooth laminar jet. When this is achieved, there is basically no seawater residue left in the tube. The water acts like a single object and uses its own viscosity to pull the water that wants to stick to the tube along with it. It self cleans in a way.

A Post-Script to this section:

Laminar flow will be governed by both the diameter of the tube and the flow velocity in the tube. With this dual tube snorkel, you will get a cleaner purge if you don't blow too hard. Stay relaxed and just give an easy exhale through the snorkel to purge. If you blow too hard (like most are probably used to doing with other snorkels) you can overpower the purge and get water velocities in the tube so high that the water's viscosity won't be able to pull the residue that want's to stick to to inside of the tubes out with it. Like all things freediving, this snorkel concept works best when you stay relaxed and don't force it.

 

[Jackin]

Thanks Ron, I get it.
That means no valve needed. Only relaxed breathing.

The worst thing for me is lenght and position of tubing enter. Every monday I test another setup with no success.
I do not know how your works, but if I have 2kg neckweight, with normal setup (on your video) it is ok and working when I am stationary in a water (face forward, face down and face a little bacwards). But if I start swimming (surface), it is total dissaster - every move with orca I take a water in inlet/outlet. Hard tubes has also one feature to fall by own weight and own round shape by storage coil over head forwards (face down you take water when you swim) or backwards (face up/forward upright with surface you take water even if you are stationary). And this tests are in a pool, open water I have not chance to survive. AFter I choose and get my new tubing, also I pick up some anti-kink coils to attach this to ends (5-10cm) and make ends direct from a head. For wave and windy conditions I am thinking about oblique ends (not flat cut), maybe it helps a little with spash water. But all of it are only speculations.

Best position for tubing ends will be as this product, AMEO Powerbreather, which is exactly the same as your applied to swimming:
Amazon product ASIN B016X8DFLS
For better clips, I am experimentig with simple O-ring for keys (two of them for a mask strap). It could be fine for quick release, whole snorkel moves by own weight down under chin when you split it, but not tested it yet. And only top clip is needed to detach snorkel from a mask. Because O-ring stays on masks strips.

Which outer diameter will be better, 13 - 14 or 16 ? Kink/flex/memmory effect by storage ?

 

[REVAN]

I have my tubes tied together at the end such that they come together aiming the same general direction (like the end of a double barrel shotgun). It looks like you have yours taped together like a lap joint and aiming in opposite directions. My method raises the openings above the head for some clearance above the waterline. How much clearance do you have to the water?

 

[Jackin]

Previous foto was only one of the tests. I was testing side attachment end of tubes. Doesnt help anyway.
Tied together - yes. But I show you what I mean:
Normal freedive snorkel position on a Mr.Head, first looking forward in a water, looking on a bottom and slightly backwards


Yes, the last might be better, you can make a snorkel out of water.

Now loop snorkel, when stocking shape from coil direct the ends to the front (PVC tubes with silicone tubes on ends for lenghten only for testing):


And when stocking shape ends to the back:

- yes, back is fine for swimming, but do not try to look more forward.

I think with anti-kink coils and straightened shape of tubes it will be universal for any movement - it have to take right diagonal from mouth to backstrape. As AMAO Powerbreather - Amazon product ASIN B016X8DFLS . When you look on it from a side, it is straight line. And long over head.

Thats why I am asking for an advice to choose right tubes (PVC, silicone, Tygon, XSPC.........10/16.....10/13......) - it DOES matter.
For experiments, I have only normal garden clear PVC 10/13 and silicone 10/14.

I like these attachements:

 

[Jackin]

whats wrong with html/link code ? anyway, google AMAO Powerbreather or you can find it on amazon. I hope that it is not advertise. Admin can clean it as he can.

Ron - you are comfortable and with clean tubes at all positions stationary and swimming, or you also have "a black spot" and take a water in tubes sometimes (no waves this time) ?

 

[Jackin]

" are you comfortable....", Im so sorry for my language....where is edit ?