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Post by james1979 on Mar 24, 2021 4:21:25 GMT -8
Gents, I've seen on the forum a recent resurgence of interest in the Dacor double hosers... and also the lament that diaphragms are not to be had. I believe they have been referred to as "Hen's Teethe." I wasn't going to say anything until I had it nailed down, but I believe I am about there.... I'm getting into Avian Dentistry and pulling the Hen's Teethe. Below is version 0.3, which will be going to a guinea pig (I mean beta tester) later this week.   It is duro 30 silicone with a duro 90 TPU reinforcing ring at the rim and an ABS friction plate cast in, all poured in a 3d printed mold with nylon stocking material for a reinforcing substrate. Version 0.4 (mold is already printed) will be slightly thick, and trying without the nylon. My main concerns are with the TPU rim reinforcement (I have a second version that I will try as well), and durability of the ABS friction plate being cast in place (might have to go with a riveted or screwed together option). Please let me know what you think, and if there is interest in them once I get the process nailed down. Respectfully, James |
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Post by nikeajax on Mar 24, 2021 8:25:26 GMT -8
Well, James... COCKADOODLE-DOO!Yes, I'd be very interested in one, but, don't print the friction plate: instead, let whomever buys one, create their own out of brass or stainless sheet-stock   JB |
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Post by SeaRat on Mar 24, 2021 9:18:37 GMT -8
There is definitely interest on my part. I have three Dacor double hose regulators, and still dive them all. My experience is that there is not much difference between the breathing effort when using the older Dacor diaphragm and their newer "low modulus" diaphragm, so this will be a welcome addition to our vintage community. Thanks for the effort.
So far as the "Avian Dentristry," is there a possibility of you going in and adding "New Dacor Diaphragm" to the title. It will make following it later much easier.
John
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Post by james1979 on Mar 24, 2021 10:24:00 GMT -8
So far as the "Avian Dentristry," is there a possibility of you going in and adding "New Dacor Diaphragm" to the title. It will make following it later much easier. Done. Regarding the friction plates, I was hoping to make it a single piece. But these are effectively hand made individually, so if you want a plastic friction plate... I'll print it in any color I have. If you want no friction plate, that can be done too. I'm getting ready to pour mold version 0.4 with a plastic exhaust spider plate, and I'll pour a 0.3 with no printed parts (solid silicon). They should all go to the guinea pig via USPS tomorrow for second opinions/constructive criticism... I'll update as it goes. These are, however, a little time consuming to make. So if (and I am still not positive on this) I get it nailed down, I'm thinking they will be a $45 part. Let me know if any of this seems off base (in either direction!). Respectfully, James |
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Post by james1979 on Mar 27, 2021 16:53:05 GMT -8
I've been slightly delayed, but 3 are going out monday to the beta tester. One exhale diaphram, with cast in exhaust spider sized for Aqualung late model Conshelf mushroom valves (would also take Kleer-EZ valves), one with a cast in friction plate, and one that will need a friction plate riveted on (I don't have any stainless or brass sheet on hand). If they pass muster, these will be an official offering.
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Post by SeaRat on Mar 27, 2021 17:48:08 GMT -8
James, Years ago, I did a quick and dirty calculation of the Dacor exhaust for both the R-2/R-3 and the R-4. The R-4 actually had less exhaust opening than the predecessors.  IMG_1699 by John Ratliff, on Flickr  IMG_1701 by John Ratliff, on Flickr If I can make a request, try to open up the exhaust so that it is greater than either of these two from Dacor. The reason, Dacor did not get U.S. Navy approval for the R-4 is the exhaust restrictions. I made the recommendation that they open up the R-4 exhaust by drilling three holes between the three rectangular cutouts, but I don’t think anyone took that to heart (I didn’t with mine either). Drilling those three holes would bring the surface area from 210 square millimeters (the previous Dacor double hose regulators had about 240 square millimeters) to 325 square millimeters. That would have improved the exhalation resistance significantly, especially at depth. John |
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Post by floridaman on Mar 28, 2021 8:27:22 GMT -8
Definatley in!
Well done btw.
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Post by james1979 on Mar 28, 2021 18:36:27 GMT -8
James, Years ago, I did a quick and dirty calculation of the Dacor exhaust for both the R-2/R-3 and the R-4. The R-4 actually had less exhaust opening than the predecessors. IMG_1699 by John Ratliff, on Flickr IMG_1701 by John Ratliff, on Flickr If I can make a request, try to open up the exhaust so that it is greater than either of these two from Dacor. The reason, Dacor did not get U.S. Navy approval for the R-4 is the exhaust restrictions. I made the recommendation that they open up the R-4 exhaust by drilling three holes between the three rectangular cutouts, but I don’t think anyone took that to heart (I didn’t with mine either). Drilling those three holes would bring the surface area from 210 square millimeters (the previous Dacor double hose regulators had about 240 square millimeters) to 325 square millimeters. That would have improved the exhalation resistance significantly, especially at depth. John John, The exhaust diaphragm headed to the tester is a 4 leg spider (along the lines of a conshelf second stage exhaust spider).... I just did the maths and came up with 436 square mm. So I think it will be an improvement of sorts! I will get them sent out tomorrow, so I hope to hear responses (good or bad) in a week or so. Respectfully, James |
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Post by vance on Apr 1, 2021 15:46:32 GMT -8
I have received a couple of iterations of James's Dacor diaphragm. Who is the mysterious beta tester? Whomever s/he is, s/he's impressed. Make your own conclusions.
This is going to elevate the vintage Dacor into the class of rebuildable regulators.
Now that there is a diaphragm, the later models are good to go, imo. However, the 2500s are still in trouble. I'm working on it. Lever height is a problem. I'll get back to you...
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Post by james1979 on Apr 1, 2021 17:03:56 GMT -8
Just a quick update on the project.
My beta tester (you can probably guess who it is) reports back....
TPU reinforcing ring is an unnecessary complication; will be dropped from future iterations.
Exhaust plate works out well, but I need to make load transmitting tabs similar to factory (I had left these out).
Cast in friction plate looked a bit janky, but functions fine ; I will be doing those slightly different going forward, should have a cleaner result.
Nylon stocking material wasn't needed.... I will still do some both ways while nailing that down (it is useful in the positioning of the friction plate within the mold).
So, within a week or two I think this will be a viable replacement product. I currently have the silicone in a translucent blue... if there is a hue and cry that opaque black is required, I'll end up ordering the pigment for it.
Just to gauge interest, who all would be interested in these (at $40 each)?
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Post by SeaRat on Apr 2, 2021 12:55:22 GMT -8
Just a quick update on the project. My beta tester (you can probably guess who it is) reports back.... TPU reinforcing ring is an unnecessary complication; will be dropped from future iterations. Exhaust plate works out well, but I need to make load transmitting tabs similar to factory (I had left these out). Cast in friction plate looked a bit janky, but functions fine ; I will be doing those slightly different going forward, should have a cleaner result. Nylon stocking material wasn't needed.... I will still do some both ways while nailing that down (it is useful in the positioning of the friction plate within the mold). So, within a week or two I think this will be a viable replacement product. I currently have the silicone in a translucent blue... if there is a hue and cry that opaque black is required, I'll end up ordering the pigment for it.
Just to gauge interest, who all would be interested in these (at $40 each)? James, I’m in for a set for my Clipper/R-4. John |
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Post by vance on Apr 2, 2021 15:09:50 GMT -8
Just weighing in here.
The double diaphragm was a gimmick, imo. It was a way around Cousteau's patent, and Dacor dropped it like a hot potato the instant they could install a duckbill w/o fear of JC's lawyers descending on their a**es. The C series regs were the result.
They are pretty good regs. (See my attempt to improve them in the Alternative Dacor Second Stage thread.)
I intend to install db's in all of my stock Dacor dive-able regs, and I'm not a fan of db's! The improvement in exhaust effort is significant.
You just don't need the second diaphragm.
That's alls I'm sayin'.
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Post by james1979 on Apr 3, 2021 4:19:04 GMT -8
Quick update.
The domed design results in the exhaust diaphragm touching the outer can (effecting the exhale resistance badly). Apparently the early domed factory ones had bumps on that side to prevent just this issue, so I will be replicating that. It will take me a bit, though, due to it needing a new mold.
I will cast a couple primary diaphragms this weekend to validate the better friction plate design on those (slightly thicker, and cleaner edge where the silicone ends to expose the friction pad).
On the 2500's, I'm talking with Phil, and we may have a solution (to the diaphragm piece) in the form of a thicker friction pad protruding inward to take up the lever gap.... more on that as Phil does the hard work!
Respectfully,
James
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Post by james1979 on Apr 28, 2021 13:24:57 GMT -8
Update time... Identified that the blue tinted silicone I was using traps air too easy to use without degassing (and here I am with no vacuum pump). My softer, clear silicone nets about 1 in 6 success rate with the current mold. So now I have more clear silicone coming, and had to order more printer filament to print the updated molds that I will try next.
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Post by james1979 on Apr 30, 2021 11:37:02 GMT -8
1st half of the new mold is printing... only 10 more hours of printing to have both halves ready to use! I also got in more of the softer silicone, so hopefully I can pour one Saturday evening. Fingers crossed!
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