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Post by SeaRat on Dec 26, 2010 23:25:16 GMT -8
Years ago, when I was first getting into diving in the winter of 1958, I was looking at different regulators. I tried out four, as I recall. A Mistral, a Healthways Scuba, A Dacor Dial-A-Breath, and maybe an Aquamaster. Each had a different price, and I had a limited budget--my berry and bean picking money from the summer before. I used each of these in the Salem YMCA pool before deciding on the Healthways Scuba. I liked the even way it drew a breath. When I tried out the Dial-A-Breath, I was fascinated because I could pull my mouth away and it kept giving air; it was the only regulator that did that. But I could not afford it, so I went for the Healthways Scuba. Many years later, in the summer of 1972, I found and bought a Dacor Dial-A-Breath at a small dive shop at Lake Chelan, Washington. I found out later that this was the original Dacor regulator. I took that regulator, and broke it down, cleaned it up, and put it back together. I dove it a couple of times, then decided that I would upgrade it to an R-4. Dacor was an interesting company, in that I could buy all the parts to make this upgrade complete, including new hoses. I got it all together, and tested it out in a lake one the Oregon coast. It did not breath well at all, so I tried adjusting the levers, and get it going better. Over the years, I kept it going and dove it in Clear Lake, Oregon. Years later, I still had that regulator, and decided to figure out what was wrong with it. I determined that the primary lever had a semi-circle-shaped curve it in which caused the lever to slide down secondary lever (the one not touching the diaphragm), which actually decreased the mechanical advantage. Well, I did it in a primitive manner, so that there were still "ripples" in the lever (a hammer tends to do that). I tested it in a pool, and found that the breathing was much better, but that the ripples in the lever caused problems. So I gave the regulator to the Dacor rep, and he was going to give it to Dacor R&D. I never heard back, and finally talked with that rep. Rather than sending me back that regulator, they sent me a "new" Pacer regulator (I say "new" because I think it came from Dacor R&D as the exhalation holes were drilled, and not punched as the regular ones were). So ended my work with the Dacor R-4. Well, just before Christmas, I won a fairly-priced Dacor Model One Dial-A-Breath. I got it just before Christmas, and have had it apart, cleaned it up, and put it back together. I actually had to pound out the HP seat, as it was completely stuck inside the chamber. I cleaned things up with vinegar, and polished the sides of that HP seat. Reassembly created a surprise--there is no way to adjust the interstage pressure. It is dependent totally upon the spring, and there is a plate without the ability to adjust the interstage pressure holding the spring in place. The rubber products were in great shape. An overnight coating of silicone grease made them good as new, and that after 50+ years. I put the regulator together, and there was just a bit of a leak in the second stage. That leak went away as the seat took a set. I tried it out, and it did not breathe all that badly. I had read that the levers should be set at the height of the ledge of the intake housing, and they seemed a bit low. So I bent them up a bit, put it together, and took some more breaths off it. Breathing was better. I had put a set of Dan's Super-Flex hoses with a Hope-Page Mouthpiece on it, and that worked very nicely. My impressions are that the Dacor Model One Dial-A-Breath is better than a BroXton (no measurements) but not quite where an Aquamaster is performance-wise. But it is a very solid, easy-to-service unit which provides adequate air upon demand. The Dial-A-Breath feature is one I'll simply have to try out in the pool to test. John Attachments:
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Post by swimjim on Dec 27, 2010 18:34:32 GMT -8
The Dial A Breath was the second generation. The originals didn't have that feature. I had one. I've also owned a couple of Dial A Breath's. They have thwarted all my efforts to make them breath very well. I'm sure part of it has to do with 50 year old high pressure diaphragms. I thought about increasing the IP using a stainless steel washer between the high pressure spring and the plate that holds it to the reg body if that makes any sense. That would up the IP. There is no way I know to check what the IP is on one of those regs. The sandwich design is also a major PIA to work with. That being said, it's a cool looking unit which is one of the reasons I was interested in it in the first place. The other reasons is that I dove Dacor Olympic single hosers back in a day and still use them on my pony. They are excellent regs. I have only recently been working on Pacer regs which were pretty darn good in their own right. The comm system the Dive rescue team I belong to has a Pacer 900 as it's reg. I just rebuilt it and it's a sweet machine. Good luck in your endeavors Searat. If you like the look and want an honest to goodness really good breather, there's always the JetAir. I really like mine.
Jim
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Post by SeaRat on Dec 27, 2010 23:26:23 GMT -8
Jim,
It is interesting to me that you talk about the originals not having the Dial-A-Breath feature; the title of this thread is just as it is written in Fred Roberts book, Basic Scuba[/B]. He begins the chapter on Dacor with this:
I had not seen that footnote until you pointed this out to me.
I think that one of the things that can be done for ease of breathing is to adjust the lever height. Fred Roberts writes about this, and it does make sense--also I pretty well proved it with mine last weekend. However, I'm pretty sure that the original hose/mouthpiece system of the Dacor inhibited the breathing characteristics of the regulator; I currently have Dan's SuperFlex hoses and a Hope-Page mouthpiece on it.
Yes, I liked the Jet Air when I had it, but it has one disadvantage--it has to go against full tank pressure at the start of the dive. This makes it most likely harder to breath than the Dacor Dial-A-Breath Dual Diaphragm regulator. The Dacor had the same type of double lever system, but working off a two-stage concept, so the difference in pressure was much less than the Jet Air had. But, the Jet Air had a better venturi, so maybe they cancel each other out.
By the way, there is one other tidbit of information--this Dacor Dial-A-Breath regulator, was an American-design. I think it was one of the first American regulators, with only four before it, being Northill, DESCO, Scott, and DivAir. Dacor was not mentioned in the 1957 edition of Rick and Barbara Carrier's book, dive, the complete book of skin diving[/B], and so may have just started out at that time as a regional company.
John
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Post by Deleted on Dec 28, 2010 7:34:20 GMT -8
jim/john
It isn't just the 1st stage springs/seat IP adjustments that make the Dacor's poor breathers, it's that freaking double lever design...
I converted one of my semi junked Dacor R4's to a MB Mk2......one of my early 1st stage designs...........the 1st stage IP was easily adjusted....I cranked it up to 135psi.........however, the 2nd stage spring is too weak for that much pressure......so after many different attempts to solve that issue I got the 2nd stage to stop leaking and its pretty sensitive......."but not by using the levers"
The resistance and cobbled design of the levers does not lend itself well to a sensitive 2nd stage.........John you found this out way back when...............
Mine breaths like my AquaMaster.......even with a balanced 1st stage and my hose in hose experiment setup. But no where close to my MK3.....
My conclusion is the same as John's.....the lever system is faulty in design.........drag resistance of the levers to breaking is the problem......a single lever has no such problem.
John you can get the ripples out by heating the lever with a propane torch till it is orange........then pound it out.......reduces stress in the metal and gets pretty smooth surface.......then a lot of polishing.........
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Post by SeaRat on Dec 28, 2010 22:13:46 GMT -8
I have photos of the tear down and what the insides of this regulator look like: This shows the smaller parts, including the base plate, the high pressure seat assembly first stage, the spring for the second stage and demand valve assembly (primary lever), and the various screws which hold this regulator together. Here is the intake housing assembly, the exhaust ring assembly, and the cover. The tools shown are all that is required to disassemble this regulator (except, of course, the allen wrench and hammer used to remove the jammed high pressure seat). And here are the three diaphragms, the pressure regulator diaphragm, the intake diaphragm assembly, and the exhaust diaphragm assembly (complete with a functioning mushroom exhaust valve). The other is the silicone grease that I coated these in overnight. Here is the regulator fully assembled. Mossback, I did go back in and bend the demand valve lever (the top one) again just a bit. Then, when I tested it, I noted that this lever assembly does act more like the Mistral lever system than the Dacor R-4 levers. This means that the mechanical advantage is increased with increased demand, not decreased. I re-assembled the regulator, and then tested it. Breathing was pretty good; even better when I took the silicone non-return mushroom valve out of the Hope-Page Mouthpiece assembly. It breaths about like a Mistral (intuitive, not measured) at this point when the Mistral is at 500 psig. I'll have some more photos tomorrow evening, I think. John
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Post by puff on Dec 29, 2010 15:51:56 GMT -8
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Post by SeaRat on Dec 29, 2010 18:09:54 GMT -8
Puff, If that had come up a month ago, I would have gone for it as it has hoses and a mouthpiece. But now I have one, so I'll let this one go to someone else. OldMossback, I just tested the two regulators, the Dacor Dial-A-Breath and the USD Mistral, back-to-back. The cracking pressure seems comparable, but the "Uummph" of the venturi is not there for the Dacor Dial-A-Breath. Now, if I can get up the gumption to make a water monometer and test them, I could quantify that impression, and compare it with other regulators, including the Mossback Mk3. That would undoubtedly be a bad regulator to compare (meaning the Dacor would fair badly), due to about 60 years of technological difference (little things like a balanced, high-flow first stage, etc.). John
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Post by nikeajax on Dec 29, 2010 19:57:17 GMT -8
John, I remember you saying that the second generation Healthways, or "blue label", as you call them, is quite comparable to the Mistral; so how does the Dacor compare the the blue label? Jaybird
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Post by SeaRat on Dec 30, 2010 9:31:50 GMT -8
Jaybird, A bit of a correction; the third generation, the Gold Label Healthways SCUBA regulator, was equivalent (or slightly better) than the USD Mistral. How does the Dacor Model One (Original Unit) Dial-A-Breath compare? Well, I hope to find out more on Sunday when I dive all these, if there is no special event at the pool. Right now, with the levers bent up a bit to give them better "purchase" on the diaphragm, I would say that the Dacor Dial-A-Breath is comparable to the Mistral, and probably slightly better than the Blue Label Healthways SCUBA, which did not have a venturi assist. I found the photo of me diving my Dacor R-4, which I built up from parts from the Dacor Dial-A-Breath original unit (which I believe was termed the R-3). This was taken in Clear Lake, which is the headwaters of the McKenzie River, in about 1974. John
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Post by SeaRat on Jan 3, 2011 18:25:10 GMT -8
As I stated on the PJ Tanks thread, I had this regulator in the water yesterday, and have interesting observations on the original unit, Dacor Dial-A-Breath. I used it on the PJ tanks (twin40+), and it performed very well. I took it down to the reserve, and found an different phenomena when I got to very low pressure. The regulator would at first breath with resistance, then surge as the venturi kicked it. Breathing returned to normal when I tripped the reserve on the right cylinder (I have the reserve reversed on this set of tanks). I then switched to a single 72 tank, and played a bit with the Dial-A-Breath feature. There was a noticeable quieting of the regulator as the venturi diminished. It breathed comparably to the BroXton, which I also used, with the Dial-A-Breath on "hard" breathing. On easy breathing, it was about like a Mistral, but maybe not quite where the Mistral is at 500 psig. I did a bit of on-line research, and found some interesting links. This one shows that the original unit Dial-A-Breath did not pass the U.S. Navy tests: oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA040145www.dtic.mil/srch/doc?collection=t3&id=ADA040145If you want a copy of the actual report, look here: archive.rubicon-foundation.org/3844Go to the lower right side, and click the link to get the download. After reading parts of it, apparently there were several studies of this regulator, and it passed the second, only to fail in this 1959 study. The criterion had changed, and so even the second "passed" attempt would have failed the newer US Navy criterion. This means that it did not measure up to the Aquamaster. I have read that Dacor tested the Dial-A-Breath unit at -60 degrees F, and I mentioned that to my son. He said that this sounded like a Military Spec too, so perhaps they were trying to pass that for Antarctic operations (it apparently passed that test). I have been able to open and read the report, and have copied two of the charts out of it. I'm pretty sure that the "competitive regulator" is a USD Aquamaster. The inhalation resistance came close to meeting the US Navy standard, but exhalation did not. The exhalation through the dual diaphragm mushroom appears to be a major problem. The surface performance is not too bad, but look at the 180 foot performance--25+ cm of H2O pressure. That's huge. In also shows that test-breathing a regulator on the surface does not show its performance at depth. My pool findings were pretty much in line with this report. I find it interesting that Dacor was not able to rectify these problems with the R-4. John
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Post by SeaRat on Jan 7, 2011 19:36:05 GMT -8
Well, I just tore my Dacor Dial-A-Breath apart to try to up the interstage pressure with a nylon washer. Took it apart, put the washer into the plate, put it back together again, saw the HP pin sitting on my table top, tore it apart again, put the HP pin into its spot, put it back together, tested it on my twin 50s at about 2700 psig, and it leaked pretty badly. So I tore it apart again, took the washer out, re-assembled it (I'm getting pretty good at it), tested it on the tank, all okay, put the cover back on, and was tightening the screws when my wife drove in from work. If I'm going to do this, I'll have to use a pretty thin washer. But I don't think I'll work with it more. It breaths pretty good for pool and shallow water use, so it will probably stay in its current state. John PS--I thought someone would be interested in the graphs from the US Navy Experimental Dive Unit showing the difference between this regulator and the Aquamaster.
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Post by duckbill on Jan 8, 2011 19:25:17 GMT -8
PS--I thought someone would be interested in the graphs from the US Navy Experimental Dive Unit showing the difference between this regulator and the Aquamaster. John, I read them with interest, and appreciate you posting them. I think many, many more than ever speak up enjoy what is posted. On behalf of all the appreciative but silent readers, thankyou.
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Post by swimjim on Jan 9, 2011 6:29:13 GMT -8
I thought the charts were interesting too John. Thanks for posting them. Ever take apart a piston reg? They use shims to adjust the IP. Some thing of a simular thickness to those would probably be the ticket for adjusting the IP on your Lung.
Jim
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Post by swimjim on Jan 9, 2011 11:46:40 GMT -8
I had an old Sportsways piston first stage on the bench today I had to reassemble from a presentation I did for the dive club. I measured one of the shims and it was .015 thick. This particular reg had two shims in it. I guess if you think about it, when adjusting the IP screw on a DA for instance, a half turn is a bunch! At any rate it would not take to much to drasticly boost the IP on your Dacor which it appears is exactly what happened. Good luck on the project if you choose to persue it.
Jim
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Post by SeaRat on Jan 23, 2011 22:21:38 GMT -8
I dove in the pool again today, and used several regulators. Concerning the contest between the DA Aqualung (BroXton) and the Dacor Dial-a-Breath, the Dacor won. I used both with the USD hose/mouthpiece system to make sure that the hoses were not a factor. The Dacor Dial-a-Breath performed better. But, not as well as either of the other two double hose regulators, the Sportsways Hydro-Twin or the USD Mistral.
Jim, after I came home, I took apart one of my USD Calypso first stages, and found two IP washers. I used both, and it boosted the IP too much (leaked), so I took it apart, and used only one washer. That sealed, so now I have probably boosted the IP about 5 psig. I haven't had it in the water since, so it will need to wait until the next pool session.
John
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