|
Post by vance on Apr 3, 2023 7:33:52 GMT -8
I have some Triestes that I just rebuilt, and was a bit surprised to see one of the second stage bodies has a setscrew threaded into one of the primary jets. It has been drilled through, creating a smaller jet. This was meant to increase the output of the unrestricted jet and so, boost the venturi effect. This probably works fine, but it does interfere with cracking adjustment since the second stage has to be turned in or out in full turns, rather than half turns.
|
|
|
Post by vance on Apr 3, 2023 14:18:46 GMT -8
I just bench tested the Trieste with the jet reducer. It's a beast! Plenty of venturi. It's probably because of James' diaphragm as well.
|
|
|
Post by vance on Apr 3, 2023 16:13:12 GMT -8
I have some Triestes that I just rebuilt, and was a bit surprised to see one of the second stage bodies has a setscrew threaded into one of the primary jets. It has been drilled through, creating a smaller jet. This was meant to increase the output of the unrestricted jet and so, boost the venturi effect. This probably works fine, but it does interfere with cracking adjustment since the second stage has to be turned in or out in full turns, rather than half turns. Quoting yourself has to be wrong, somehow. But here I go, doing it again! Bill T. concocted a genius mod on his Trieste that utilized setscrews that entered the jets vertically, rather than horizontally, like this one does. Bill's is much more sophisticated, as the setscrews can be lowered or raised to increase jet flow. The setscrew mod here has to be drilled open by degrees to achieve different results. Add to that, a diaphragm design by James that makes this reg come alive. Wow. To quote Wayne, we're not worthy.
|
|
|
Post by james1979 on Apr 3, 2023 16:40:59 GMT -8
I have some Triestes that I just rebuilt, and was a bit surprised to see one of the second stage bodies has a setscrew threaded into one of the primary jets. It has been drilled through, creating a smaller jet. This was meant to increase the output of the unrestricted jet and so, boost the venturi effect. This probably works fine, but it does interfere with cracking adjustment since the second stage has to be turned in or out in full turns, rather than half turns. Quoting yourself has to be wrong, somehow. But here I go, doing it again! Bill T. concocted a genius mod on his Trieste that utilized setscrews that entered the jets vertically, rather than horizontally, like this one does. Bill's is much more sophisticated, as the setscrews can be lowered or raised to increase jet flow. The setscrew mod here has to be drilled open by degrees to achieve different results. Add to that, a diaphragm design by James that makes this reg come alive. Wow. To quote Wayne, we're not worthy. To be fair, it isn't "my" diaphragm design, it's just my application of Bill's ideas.... A collaboration that was primarily his idea's and my wrenching (brute labor, lol).
|
|
|
Post by vance on Apr 3, 2023 16:48:57 GMT -8
You are both amazing contributors. Thanks for doing what you do!
We have a number of members who are striving to make vintage regulators work as well as modern equipment with mods, ideas, historical information, etc. Thanks to you as well!
|
|
|
Post by SeaRat on May 29, 2023 17:43:28 GMT -8
As James mentioned I dove with the newest version 0.2 on Tuesday. Couldn't get any of my lightweight diving friends to go due to 58 degree water, so went solo to get the testing done. It was a fairly warm day but the wind was creating a chop reducing visibility on my windward shore to 10', but that's not bad for Texas lakes. As expected the Trieste breathed smoothly and evenly even with heavy breathing. The bottom leveled off at 43', which was just as well since visibility had dropped to nearly nothing by 40'. As I cruised back up to more interesting terrain I began to notice a little "click" feeling at the beginning of each inhalation, and every few breaths there was a noticeable increase in effort so I stayed above 20' on the way back to exit place. I originally suspected that the duckbill eliminator may be causing some interference since I already knew was touching and tilting the diaphragm a bit on one side before diving. When I opened reg up I found that the center disc of diaphragm was separating from the silicone for about 180 degrees. I supposed the issue could have been initiated by the DBE contact with one side, but further exam revealed that the disc was easily dislodged from its retaining groove anyway. (I'll still going to replace the DBE with a normal duckbill since there just isn't enough room for it in the can) After explaining the issue to James he quickly came up with a potential cure and has already cast a new version of the diaphragm that should provide better retention of the disc. I look forward to another cool water dive for testing. Too bad some of you northern polar bear types aren't here to join in the trial dives. It has been a pleasure working with James on the evolution of the diaphragm, and I feel certain it will be soon be perfected. Having no one to take photos during the dive this is the best I could do with my phone held over my head before the dive with Trieste mounted on my inverted 27's. My 8 year old Hydroglove drysuit is holding up well and kept me comfortable for two 30 minute dives: James, I finally got my Trieste II with it's new, Silicone diaphragm replacing my own home-made diaphragm from twenty-plus years ago. I really put it through its paces in a dive that went kinda sideways today (Memorial Day, May 29, 2023). I dove High Rocks on the Clackamas River, and the water level was high. Normally there is a small island upstream of the High Rocks area, and it was almost completely submerged. There was quite a current going straight into the rapids at a 90 degree angle, and rather than riding it underwater under the rapids, it mixed and became a mix of sweraling water, upwelling, and down currents conflicting with huge rocks that had been moved in the winter floods. I was wirled around in this turbulence three full circles and was at times upside down and backwards. My float's line caught in my helmet-mounted GoPro, and would not release, and that led to a flooding of my facemask. I finally got below this sweraling mess and into calmer water, with my mask completely flooded, and got to the side where the rock wall went straight up. I got my helmet loos, removed the line, and got things under control, while loosing my helmet (it sank to the bottom), got everything straightened out, and went down twenty feet and recovered the helmet. I then looked up at the lifeguards, and holding onto my float told them of my experience and that the currents above High Rocks were extremely hazardous. After that, I went down and started again a more normal dive, noting that the bottom had been re-arranged by winter floods. Large rocks seemed to have been moved. I came to a rock, went around it and in a shallower area surprised about a 7 foot sturgeon (at least, it looked to me to be 7 feet long). It departed as soon as it spotted me coming at it. Throughout this dive, the Trieste II with its new silicone diaphargm, performed flawlessly. I got all the air I needed, under extremely trying circumstances. I would highly recommend this diaphragm on any Trieste that has the original AMF Voit diaphragm (with it's baked-in "set" adding at least an inch of water pressure to inhalations). At one point, I was on the regulator on the surface as I could not clear my mask until I got to share and released the line attached to my helmet. So looking toward shore got me only a very fuzzy image of the rocks on he river's edge. This was the most challenging dive I've had in decades, and I'm still working out some of the "stuff" that went wrong. But the things that went right were my new boots, I didn't loose a fin, my float worked (but that line is a real problem). I was diving my twin 44s, and started with 2900 psig in the tanks and ended with 1400 psig, starting at about 12:58 PM and ending at 1: 40 PM. What was interesting was that as I walk walking with full gear up the hillside on a trail toward my car, two fellow saw me, came over and talked to me. One said his father had been a diver, so he knew how heavy my tanks and weight belt were. They asked if they could help me carry the gear, and I said I was just going about fifty feet more and then dumping it. They followed me up, and then asked if they could carry my gear to the car (it was about 100 yards up the road, but on the level). I said "Sure, that would be great." They took my tanks and float, and I hand-carried my weight belt. I had one guy get into my tank harness system, so that it would be easier to haul ("Like a backpack," his friend said). We got to the car, and I thanked them. Wow! I had never been treated like that before. 'Turn's out I am older than when one guy's Dad died (I'm 77 this year). Anyway, I thought you and the others would enjoy hearing about my Memorial Day dive today. John
|
|
|
Post by vance on Jun 7, 2023 10:27:40 GMT -8
I suppose this is a clearance issue, like the modded DBE failure? The new DB is notably thicker than the old flat ones. I hope to get someone with a magnehelic to check the difference in exhaust effort. Best I can tell, with a failed intake non return the exhaust effort is just high enough to balloon the diaphragm just enough to start to constrict the DB.... thereby increasing exhaust effort further, choking off the DB. The failure mode requires 3 things to all be present: 1) New diaphragm (Specifically the ones I make) 2) New style Duckbill (Scuba Museum is the only source for them I know) 3) Failed intake non-return. It's technically a secondary effect of a failed intake non-return, but I'm not pleased with it even if it is easily handled by exhaling around the mouthpiece until the dive is over and replacing the non-return. I have 3 solutions in mind, of varying difficulty/concern for me (minor mod to the diaphragm, redesign of diaphragm for lower height, or development of DBE specific for the Trieste). Full time job and family will slow down the work on this, but I'll advise as I go. Respectfully, James I just sold a Trieste, and had to get it tuned up in order to ship it out. It developed the inhibited exhaust effect with a formed duckbill. I noticed the diaphragm ballooning when exhaling, so I switched out the flat non-returns for a set of VDH's new, improved wws and valves. That helped, but didn't eliminate the interference. I thought I was going to have to go with the TSM diaphragm, but installing a flat db fixed the issue. I happen to have an OEM Trieste diaphragm, and compared it to the TSM reproduction and the James version. Both the TSM version and James's version are taller than OEM. The TSM is about 1/16" taller and James's version about 3/16" taller.
|
|
|
Post by vance on Jun 7, 2023 10:50:01 GMT -8
In experimenting with the Trieste, I tried a couple of things. The setscrew jet that was installed in this second stage led me to think that fine tuning could be done with various jet sizes, so I drilled out a few in different sizes.
The maximum size is limited by the hex socket in the #6-32 setscrew, but I found that the largest (drill bit #48) was too large for the OEM second stage configuration, and lowered the venturi strength too much. Surprisingly small differences in jet diameter made big differences in performance. I ended up with really good performance at #46.
A few other things affect tuning the venturi. One is the secondary jet's relation to the position of the HP spring retainer. On the HPR, Luis uses little plastic bits on the retaining ears to block or reduce the bleed jet output. The corners of the HP spring retainer can act like that and influence the output of the secondary jet. Having the flat of the spring retainer square with the secondary jet is the best, but it's hard to clock!
Another is the position of the setscrew in or out. If the setscrew "tube" is too close to the spring boss inside the second stage body, it can also inhibit the secondary's airstream. BTW, blocking or inhibiting the bleed jets or secondary jet increases the velocity of the primary jet.
|
|
|
Post by vance on Jun 7, 2023 10:59:19 GMT -8
I also fooled around with the TSM diaphragm. The idea was to improve fit with flowable silicone. I skooshed some around the top rim of the diaphragm and laid it in the bottom box. I carefully centered it and then set the regulator on top. After it set a bit, I installed the clamp.
After 24 hours, I tried it on a tank for leaks. Worked fine. I took off the cover and peeled off the diaphragm. It came away easily, and the flowable silicone adhered very nicely to the diaphragm. It really sticks! The silicone makes a nice enlarged rim that allows for easy installation.
|
|
|
Post by james1979 on Jun 7, 2023 11:47:03 GMT -8
The new DB is notably thicker than the old flat ones. I hope to get someone with a magnehelic to check the difference in exhaust effort. Best I can tell, with a failed intake non return the exhaust effort is just high enough to balloon the diaphragm just enough to start to constrict the DB.... thereby increasing exhaust effort further, choking off the DB. The failure mode requires 3 things to all be present: 1) New diaphragm (Specifically the ones I make) 2) New style Duckbill (Scuba Museum is the only source for them I know) 3) Failed intake non-return. It's technically a secondary effect of a failed intake non-return, but I'm not pleased with it even if it is easily handled by exhaling around the mouthpiece until the dive is over and replacing the non-return. I have 3 solutions in mind, of varying difficulty/concern for me (minor mod to the diaphragm, redesign of diaphragm for lower height, or development of DBE specific for the Trieste). Full time job and family will slow down the work on this, but I'll advise as I go. Respectfully, James I just sold a Trieste, and had to get it tuned up in order to ship it out. It developed the inhibited exhaust effect with a formed duckbill. I noticed the diaphragm ballooning when exhaling, so I switched out the flat non-returns for a set of VDH's new, improved wws and valves. That helped, but didn't eliminate the interference. I thought I was going to have to go with the TSM diaphragm, but installing a flat db fixed the issue. I happen to have an OEM Trieste diaphragm, and compared it to the TSM reproduction and the James version. Both the TSM version and James's version are taller than OEM. The TSM is about 1/16" taller and James's version about 3/16" taller. Phil, At the time of that discussion, the final decision was that redesigning the diaphragm wasn't warranted for an issue that requires a confluence of factors (and John contributed that the blocked duckbill in this scenario is not unique to the Trieste/this diaphragm). The greater height of the diaphragm I make is intentional, from the collaboration with Bill, to allow room for second stage tuning via backing it out to reduce cracking effort. If people decide it's warranted, I can do another one with a lower height.... just debating the bang for buck trade-off. Respectfully, James
|
|
|
Post by vance on Jun 7, 2023 13:34:57 GMT -8
I think that the flat duckbill compromise is probably good enough, but I think there's still a bit of interference.
I can't imagine you can get a better intake non-return seal than the improved valve version makes, but there's still a bit of ballooning. I tried with several new sets....
For the limited number of needed new Trieste diaphragms, making a new mold isn't necessary. In the event that new flat dbs become unavailable, then?
|
|
|
Post by vance on Jun 7, 2023 13:45:41 GMT -8
I forgot to mention something pretty important. The horizontal setscrew jetting system is nowhere near as easy to do as Bill's vertical method. Mine requires disassembly, reassembly, testing, disassembly, reassembly, testing, and on and on. Bill's adjustments can be made easily w/o taking everything apart, and, if you make both primary jets adjustable, you retain the 1/2 turn cracking increments.
If I ever do something like this again, I will def learn from Bill T!
|
|
|
Post by SeaRat on Jun 7, 2023 17:30:23 GMT -8
I just sold a Trieste, and had to get it tuned up in order to ship it out. It developed the inhibited exhaust effect with a formed duckbill. I noticed the diaphragm ballooning when exhaling, so I switched out the flat non-returns for a set of VDH's new, improved wws and valves. That helped, but didn't eliminate the interference. I thought I was going to have to go with the TSM diaphragm, but installing a flat db fixed the issue. I happen to have an OEM Trieste diaphragm, and compared it to the TSM reproduction and the James version. Both the TSM version and James's version are taller than OEM. The TSM is about 1/16" taller and James's version about 3/16" taller. Phil, At the time of that discussion, the final decision was that redesigning the diaphragm wasn't warranted for an issue that requires a confluence of factors (and John contributed that the blocked duckbill in this scenario is not unique to the Trieste/this diaphragm). The greater height of the diaphragm I make is intentional, from the collaboration with Bill, to allow room for second stage tuning via backing it out to reduce cracking effort. If people decide it's warranted, I can do another one with a lower height.... just debating the bang for buck trade-off. Respectfully, James James, I don't think you need to re-design the diaphragm. The situation I talked about was with the Healthways Scuba Deluxe and involved the new silicone diaphragm for that regulator, and my experiment with a hose look without non-returns in the mouthpiece. I had total blockage when I entered the water of the exhalation mushroom valve, which is a different type of valve from the duckbill. I simply could not exhale through the exhalation hose. It was totally blocked. I had to get out of the water at High Rocks on the Clackamas River, walk up to my car, and get a different regulator to continue diving. So much for that experiment. My engineering control was to glue a nut onto the bottom box so that a seal could not be made over the mushroom exhalation valve. The Gold Label actually covered that situation, with a metal projection off the bottom box beyond the mushroom valve. IMG_1422 by John Ratliff, on Flickr IMG_1417 by John Ratliff, on Flickr The situation with a Trieste is with a duckbill valve, which although it can be inhibited cannot really be easily completely blocked. This is due to the design of the duckbill itself. Also, the Trieste diaphragm is smaller in diameter, and probably cannot "engulf" the duckbill so as to completely chock off the exhalation. By the way, I as described above conducted a very intense test of this diaphragm in a high current, turbulent Clackamas River situation, and it passed with flying colors. I had a VDH DSV mouthpiece in the hose loop, and it completely closed off the inhalation hose with the non-return valve in the mouthpiece. John
|
|
|
Post by vance on Jun 8, 2023 7:49:29 GMT -8
In my Trieste, with a formed duckbill and new silicone diaphragm, the duckbill was completely blocked on exhale, even with a new intake non-return in the m-p.
|
|
|
Post by antique diver on Jun 13, 2023 4:43:11 GMT -8
In my Trieste, with a formed duckbill and new silicone diaphragm, the duckbill was completely blocked on exhale, even with a new intake non-return in the m-p. On the Trieste I have tried a modified duckbill eliminator, new type silicone duckbill from The Scuba Museum, and the simple flat silicone duckbill from VDH. Due only to the limited depth of the stock Trieste exhale can the only thing that works well for me has been the flat silicone duckbill. On most other double hose regs the flat duckbill would be my last choice of the three.
|
|