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Post by SeaRat on Dec 13, 2018 21:56:54 GMT -8
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Post by vance on Dec 14, 2018 10:00:33 GMT -8
Yes, I copied the size and configuration of the jets. This one is an experiment, and subsequent ones will incorporate some differences. I will try a 3 jet pattern, different size holes, and different locating groove positions. Mainly, the issue for me in making this thing is the length of the LP seat holder. I'm using a DA seat holder and it is a lot shorter than the Trieste's. There are several reasons to use the DA seat holder: one is availability, another is the shaft is round, another is that I have some, etc. Cutting a square hole for the Trieste style shaft is a problem. You can't use a square drill bit! As I mentioned, this adds the problem of sourcing a spring that reduces the increased cracking effort produced by the shortened body/stock spring. I am reinventing the wheel here. This problem has been attacked and solved before. However, it is fun and I enjoy thinking about the problems and adding my mods to the mix. I am not considering manufacturing these, this is simply a challenge. I don't have the resources to test this extensively for performance and durability. And, how many people would want to modify their Titans II? There are probably more failed attempts at making the LP body in my lathe tray than there are Titans out in the wild!
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Post by vance on Dec 14, 2018 10:10:42 GMT -8
I have also put a Titan II into plastic FX cans. I didn't really want to do it this way, but I decided that I didn't want to cut up any vintage cans.
One problem with this is that the venturi jets don't line up with the intake horn unless the Trieste body is turned awkwardly in the cans. Because the Trieste's yoke is stationary, and the original Trieste boxes are smaller and the horns are at a steeper angle, the geometry is changed. When you line the Trieste yoke up square with the tank valve and the horns, the jet is off a bit.
I can fix this when I make a new LP body for it, but I'm wondering what others have done?
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Post by SeaRat on Dec 14, 2018 14:48:31 GMT -8
Yes, I copied the size and configuration of the jets. This one is an experiment, and subsequent ones will incorporate some differences. I will try a 3 jet pattern, different size holes, and different locating groove positions. Mainly, the issue for me in making this thing is the length of the LP seat holder. I'm using a DA seat holder and it is a lot shorter than the Trieste's. There are several reasons to use the DA seat holder: one is availability, another is the shaft is round, another is that I have some, etc. Cutting a square hole for the Trieste style shaft is a problem. You can't use a square drill bit! As I mentioned, this adds the problem of sourcing a spring that reduces the increased cracking effort produced by the shortened body/stock spring. I am reinventing the wheel here. This problem has been attacked and solved before. However, it is fun and I enjoy thinking about the problems and adding my mods to the mix. I am not considering manufacturing these, this is simply a challenge. I don't have the resources to test this extensively for performance and durability. And, how many people would want to modify their Titans II? There are probably more failed attempts at making the LP body in my lathe tray than there are Titans out in the wild! The advantage of the square hole is that it is easy to unscrew the nut on the seat holder. With the USD round configuration, you had to lift the seat holder and hold it with a needle nose pliers to get that nut off. The U.S. Navy didn't worry about that, as their procedure was to simply cut the seat holder and then replace it during maintenance. To reduce the spring tension, why not simply unscrew the assembly? That seems a lot easier than figuring out a new spring. John
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Post by nikeajax on Dec 14, 2018 15:20:18 GMT -8
Phil, can't you find a file that size, to drill the hole and square off some corners? I know that ScubaPro has square poppets you can drop in too. You can probably use and Xacto knife to really finish things too: the blades are harder than brass! I know how much you'd hate having to get yet another tool Just brain-storming JB
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Post by vance on Dec 14, 2018 16:13:54 GMT -8
The new style holders by VDH have a screwdriver slot at the top. I want to use one of them. This makes it adjustable w/o removing the LP nozzle/body. The nut is held in place with nail polish rather than staking.
Backing the nozzle out is probably the answer to the cracking effort problem! For those of you who don't understand this, the nozzle on these, the RAM, DAAM, and etc are not screwed down tight. They might be backed out a turn or two. They are locked in place by various schemes. The Trieste uses a screw head captured in a groove, and the USD regs have little tabs that hold the nozzle. Good thinking John!
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Post by vance on Dec 14, 2018 16:17:47 GMT -8
Phil, can't you find a file that size, to drill the hole and square off some corners? I know that ScubaPro has square poppets you can drop in too. You can probably use and Xacto knife to really finish things too: the blades are harder than brass! I know how much you'd hate having to get yet another tool Just brain-storming JB Whoo. Don't relish that task! I think the DA holder will work fine. The nozzle body can be machined to accommodate the shorter shaft. Thanks for the suggestion, though! I appreciate the thinnin' BabaLooie! Keep those ideas coming!
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Post by herman on Dec 14, 2018 17:09:39 GMT -8
Just use one from a Conshelf (and most other USD second stages). It is longer but needs to have the threads extended a little but that is easy with a die. That is what we used on the Pegasus project. FYI, the threads are 5-40 (NOT the more common 4-40)they were used on all USD second stages, both DH and SH.
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Post by vance on Jan 16, 2019 18:33:49 GMT -8
Just use one from a Conshelf (and most other USD second stages). It is longer but needs to have the threads extended a little but that is easy with a die. That is what we used on the Pegasus project. FYI, the threads are 5-40 (NOT the more common 4-40)they were used on all USD second stages, both DH and SH. This is what I was asking about, Herman!
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Post by vance on Apr 19, 2019 12:14:12 GMT -8
I made some progress on the Titan II DH conversion today: I made the lever out of stainless sheet that I had laying around. It's a bit crude, and is not finished on the diaphragm end. I need to make some teflon contact bumps for it. I'll probably make a new one out of stronger stainless now that I've gone to school with this one. I'll leave a bit more meat on the new one. I got a bit over-zealous with the file on this one. I drilled the second stage jets in a 3 hole pattern (1 large, 2 small). The Titan doesn't fit quite right in the FX cans. If the stock second is used, the venturi jet is pointed nowhere near the intake horn when the fixed yoke is oriented correctly. I drilled my second stage off center so the air is directed at the side of the intake horn. You can see the hole in this pic: I also cut a groove in the 2nd's body for a set screw to keep it from turning, ala the Trieste: It appears to work too well. I'm concerned the venturi is too strong with the 3 hole pattern. I can always open up the 2 small holes to weaken it a bit, if necessary.
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Post by vance on Apr 19, 2019 13:55:34 GMT -8
I made a new lever, and decided to bend the ends of the first attempt for diaphragm contacts while I source some teflon for the new one. I wanted to test the assembled reg for venturi action. This shows the newly bent lever and the 2nd stage setscrew installed: I put it all together and tried it out on a tank. Yup. Lung buster. Got to drill out the 4th hole or enlarge the two small ones. I think, since the Trieste works fine in the FX cans, that copying the jet bores and # of jets is the way to go. I don't want to get all calculatey about this....
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Post by vance on Apr 21, 2019 11:34:22 GMT -8
I drilled out the second big hole opposite the main jet and it works perfectly. Easy cracking effort and it delivers lots of air. I think this will be a great breather. I'm looking forward to the pool test!
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Post by vance on Apr 21, 2019 17:16:47 GMT -8
Just bought another set of FX cans for the Titan II/Trieste. I'll be modding the lever for an HPR I installed on another Titan II, which will go in these cans. The stock HPR lever is too long, and makes the contact point off-center. This is a superior DH rig!
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Post by SeaRat on Apr 21, 2019 18:14:17 GMT -8
This looks like it will work very well. I would suggest not changing the hole pattern, and seeing if it is indeed too strong (blow-by through he mouthpiece). If it is, then fix it in the mouthpiece rather than in the hole pattern. I did this, and used it for many years with my Trieste II. I used a Healthways baffle plate for their mouthpiece, and simply glued it into the AMF Voit/USD curved mouthpiece. That way, the air goes to the diver at very little effort, and the Trieste II becomes one of the best-breathing double hose regulators ever. Try it...I think you'll like it. if not, you can always re-drill the second stage holes.
John
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Post by vance on Apr 21, 2019 19:14:27 GMT -8
I already drilled the second stage holes. The blow-by/freeflow with only 3 holes was huge. After drilling an opposite hole from the main jet, it works great! Plenty of air and a nice venturi effect. I'd like to work out an adjustable venturi on another second stage I'll make. That'd be awesome.
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