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Post by technidiver on Feb 18, 2019 20:27:38 GMT -8
If you ever notice how a DH becomes a positive pressure breather when you get on your back, that is basically what chest mounted does to a DH. It is still a demand valve, it is just biased to work in a positive pressure mode. You actually have to hold your mouthpiece with your teeth. It would work with a full-face-mask if you had to dive in contaminated water. One big disadvantage of chest mounted is that now you can end up with a lot of bubbles in your face. If you do a search for chest mounted you will find a number of related threads. Here are a couple of links. From 2009: www.vintagedoublehose.com/forum/viewtopic.php?f=4&t=3773&hilit=chest+chest+mountFrom 2012: vintagedoublehose.com/forum/viewtopic.php?f=4&t=6513&p=56100#p56100From 2015: vintagedoublehose.com/forum/viewtopic.php?f=4&t=8042&p=65950&hilit=chest+mounted#p65950During Sand Dog IV (in 2007) I tested a new Mistral on a chest mounted configuration. Since the first and second stage can be easily separated, it made it very easy to try it in this configuration. The cracking effort was biased towards a positive pressure breather, but that did not resolve the lack of any venturi assistance. This was in June 24, 2012.
Luis, what Regulator body is that? Are those FX Cans in the second photo? Looks like an aqua master second stage that has the plug in it. I would like to recreate one of those. TD
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Post by SeaRat on Feb 18, 2019 20:34:52 GMT -8
The Royal Aquamaster performed much better than any of the single stage regulators. As I said earlier, I had tried mounting this setup with the Healthways Hybrid Scuba regulator (Gold Label innards, original box), but that did not work too well. I think that setup needed a higher pressure with this valve to work. Here it is with the Healthways Hybrid Scuba regulator. This problem probably isn't the regulator's, but rather the Sherwood valve. John
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Post by SeaRat on Feb 18, 2019 20:42:43 GMT -8
Okay, here's a comparison of the center section of the Sherwood twin tank manifold and the U.S. Divers Company (now Aqualung) center sections. If you look at the routing of the air, the air in this Sherwood manifold comes from the two outside tanks, to the center section's middle, then up the middle to the turnoff valve. It then goes down the valve's section to the place where the regulator attaches. This is a rather convoluted routing, in that the air must turn 90 degrees, go up, turn 180 dergees, and go down then turn 90 degrees again. This seems to set up a lot of turbulent flow, causing the hard breathing at low air pressures demanded by this chest-mounting system. Here's the USD valve: Looking down at the air routing through this valve, the air comes straight in from the tanks on either side, makes a 90 degree turn, then heads down toward the regulator, where it makes another 90 degree turn. It is a much more straight-forward routing than the Sherwood system. I think that U.S. Divers Company at that time probably had a patent that extended to the routing of the air flow through this manifold. I cannot explain why Sherwood would use the routing that they did otherwise. Saying that, I have no problem with any of my single stage regulators mounted directly on a Sherwood manifold and used in the normal manner. There must be something more to it, but it does seem that the valve routing plays a roll. John
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Post by pabloo on Dec 18, 2023 2:49:03 GMT -8
Hello,that is interesting idea...I made small chest mounted set with Polish reg KAIMAN R7. It needs only small tune - was to "sensitive" on the chest position. Breathing resistance was similar on every diver position. Regards Pawel
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Post by SeaRat on Dec 18, 2023 9:26:18 GMT -8
Hello,that is interesting idea...I made small chest mounted set with Polish reg KAIMAN R7. It needs only small tune - was to "sensitive" on the chest position. Breathing resistance was similar on every diver position. First, welcome here! It's good to have someone new posting here. I have had some problems with this chest-mounted setup, and have not been experimenting with it since these postings in 2019. John
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Post by pabloo on Dec 18, 2023 10:43:09 GMT -8
Hello John I found somewhere "chart" comparing two hose with single hose breathing resistance. I put extra label "chest mounted double hose" . The reg is (should be) directly on the chest and the mouthpiece also can be close to exhaust valve level. I am not a diving physiologist but "harder exhalation" makes me less fatigue than "harder inhalation"... I thing that for breathing muscles is easier "compress" than "suck" the chest under water - am I right ? The regulator with normal (backside) mount regulation was very sensitive and easy makes "air blows" - with tuning works better. After my set testing breathing is very similar on every position with "positive pressure" inhalation during diver's horizontal position. So even simple (unbalanced , without suppor) vintage double hose regulator can be "nice breathing" machine when is "chest mounted" Regards Pawel
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Post by vance on Dec 18, 2023 16:28:20 GMT -8
First of all, welcome to the forum! It's great to have you on board.
Do I detect an Eastern European "accent" in your writing? Also the Kaiman reg could be a hint?
Anyway, I have also been curious about chest mounting DH regs, but never pursued it to the point of an actual working and tested setup.
I have a Soviet AVM-3 (a DH second stage only regulator) for which I made some adapters to hook up a remote US made first stage. I also had some Narghile (Spiro hookah regs) that I considered for chest mounting. I also made adapters for these, but I never followed through with making a harness to try either of these models out.
I sold the Narghiles and am listing the AVM-3 on eBay, so it's unlikely I'll ever do this. It's an intriguing idea.
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cg43
Senior Diver
Posts: 87
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Post by cg43 on Dec 18, 2023 16:41:49 GMT -8
Hello John
If I see it right , you are using hp component's for Ip ? For an realistic test with IP feed you must use a second stage reg. with only the second stage connected and all the air chanel not less then 5mm diameter .
If you only want to test the influence of the chest mount , it's better to use a reg. with weak or better no ventury . The ventury tends to level the differences in the inhale .
I made tests with the Medi doubelhose (only second stage) and an rebreather with chest mounted counterlung .
I will write about my experience later .
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Post by SeaRat on Dec 18, 2023 18:03:15 GMT -8
Pabloo and cg43, My adaptor for the chest-mount was a center section of a double manifold, as shown below: IMG_1045 by John Ratliff, on Flickr I think the interior diamoter was okay, but my implementation bad. I used an Aquamaster double hose regulator, rather than a Mistral and Healthways Scuba (two single stage regulators). But I bypassed the first stage of the Aquamaster, by hooking into the hookah adaptor in the Aquamaster. I had mounted it on my Para-Sea BC, but it flopped around, and I had some other problems that dive, and ended up abandoning the concept. I used two first stages, set at about 140 psig. It appears that the internal diameter is less than the 5mm you suggested, which may explain why my experiment failed. John
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Post by pabloo on Dec 19, 2023 0:33:02 GMT -8
Hello Vance Yes, you are right, I am from Poland and apologize for possible language mistakes The "vintage diving" is not so popular idea in my country that's why I am here:) Some time ago I was interested about chest mounted DH regulator and I found plenty examples of using reg in this position... Even belly mounted by modern, professional diver if you like Finally, I found an article about Poumondeau by Georges Herail. He made innovative scuba regulator also in chest mounted version. And small front mounted apparatus. Compact set for "shallow water fish watching" is very interesting...you can easy take it with suit and basic gear in to one bag. Or give it to your child to show "underwater world" beauty ... So I have to make one like that:) I used my KAIMAN R7 single stage unloaded with venturi nozzle regulation - it's easy to maintain on the chest position. Tanks 2x2L per 200 bar are not so big/heavy so could be easily care on belly. Second regulator (UAN-82) and pressure gauge was added for safety. Regulator was tuned and tested few times up to 3m and was OK. I found a contact with retired Navy diver experienced with Kaiman. He was the one of first divers tested and putting the Kaiman in to Navy service in the 1970s also serviced them for years. He was surprised but happy that someone is so "crazy" to do something like that with old gear. He has a lot of original spare parts and he agreed to check & prepare my regulator for "safe" deeper diving. It will be nice I hope that now all will be well visible...thank you again Vince
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Post by vance on Dec 19, 2023 9:28:15 GMT -8
Hello Vance Yes, you are right, I am from Poland and apologize for possible language mistakes The "vintage diving" is not so popular idea in my country that's why I am here:) Some time ago I found an article about Poumondeau by Georges Herail. He made innovative scuba regulator also chest mounted ...and small front mounted apparatus. Compact set for "shallow water fish watching" is very interesting, you can take it with suit and basic gear in to one bag. I have to make one like that:) U used one of my KAIMAN R7 single stage, no need stage separator, so easy to maintain on the chest position. For chest mount required regulation of opening tension and Venturi nozzle. Tanks 2x2L per 200 bar are not so big/heavy so could be easy care on belly. Set was tuned and tested few times up to 3m and was OK. Second regulator (UAN-82) and pressure gauge was added fir safety. I found a contact with retired Navy diver experienced with Kaiman. He was the one of first divers tested and putting the Kaiman in to Navy service in the 1970s also serviced them for years. He was surprised but happy that someone is so "crazy" to do something like that with old gear. He has a lot of original spare parts and he agreed to prepare my regulator for safe diving. It will be nice It was the occasional lack of articles in your writing! I do not criticize! Your English is excellent, and far better than my Polish. I always admire people who can communicate in a second (or more) language. For posting photos on the board, please read here: vintagescuba.proboards.com/thread/5473/using-imgur-post-photos and here: vintagescuba.proboards.com/thread/5261/using-flickr-host-site-postingWe'd all love to see photos of your equipment!
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Post by nikeajax on Dec 19, 2023 9:43:33 GMT -8
Pabloo, tak, cześć! BRAWO PAN!!!!! Jeśli chodzi o szaleństwo, nigdy całkowicie nie ufam nikomu, kto twierdzi, że jest zdrowy na umyśle. W Stanach Zjednoczonych mamy takie powiedzenie, że ktoś jest „szalony jak sójka”. Więc po co być normalnym? Pabloo, yes, welcome! BRAVO SIR!!!!! As for being crazy, I never completely trust anyone who says their normal. In the States, we have a saying that someone is as “crazy as a jaybird”, why be normal? JB (Jaybird)
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Post by pabloo on Dec 19, 2023 10:24:33 GMT -8
Thank you Vance Yes, I have a small problem with adding the pictures (firstly to Google) so it makes disorder, sorry of that gents. I will following your hint, thanks.
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Post by antique diver on Dec 19, 2023 13:04:18 GMT -8
Pabloo, tak, cześć! BRAWO PAN!!!!! Jeśli chodzi o szaleństwo, nigdy całkowicie nie ufam nikomu, kto twierdzi, że jest zdrowy na umyśle. W Stanach Zjednoczonych mamy takie powiedzenie, że ktoś jest „szalony jak sójka”. Więc po co być normalnym? Pabloo, yes, welcome! BRAVO SIR!!!!! As for being crazy, I never completely trust anyone who says their normal. In the States, we have a saying that someone is as “crazy as a jaybird”, why be normal? JB (Jaybird) Wow... JB, my eccentric friend... I always thought that reference was really just about the actual bird with blue feathers. Now I'm beginning to understand!
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Post by nikeajax on Dec 19, 2023 15:43:23 GMT -8
Pabloo, tak, cześć! BRAWO PAN!!!!! Jeśli chodzi o szaleństwo, nigdy całkowicie nie ufam nikomu, kto twierdzi, że jest zdrowy na umyśle. W Stanach Zjednoczonych mamy takie powiedzenie, że ktoś jest „szalony jak sójka”. Więc po co być normalnym? Pabloo, yes, welcome! BRAVO SIR!!!!! As for being crazy, I never completely trust anyone who says their normal. In the States, we have a saying that someone is as “crazy as a jaybird”, why be normal? JB (Jaybird) Wow... JB, my eccentric friend... I always thought that reference was really just about the actual bird with blue feathers. Now I'm beginning to understand! California scrub jay (Aphelocoma californica) JB
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