|
Post by vance on Oct 20, 2018 10:36:50 GMT -8
I have always wanted to convert a single hose SwimMaster Titan II to double hose, and I'm fittin' to do it. I picked up a Trieste in need of a rebuild, and while I was at it, I got a Titan II for a conversion project. I spent too much on the Trieste and next to nothing for the Titan II, so with cost averaging, I did ok! Several things are going on with this. The Titan II is a Trieste body with a plugged second stage port. Mine has a cap with an LP disk and retainer in it, which blocks the LP side, rather than a plug. Interesting. It isn't a Trieste second stage carrier, since there's no slot for the lever to fit. Too bad. That would have made things easy. I am probably going to use an HPR second stage from VDH in the Titan II. Some modification has to be made for it to fit, since the thread pitch is slightly different. Luckily, the necessary body to can retainer ring and gasket from a DA fits the Titan body. Instead of using a new plastic set of cans, I am planning on using a top can from a DA, or if necessary, I'll convert a Mistral can to fit. I hate cutting up vintage parts, though. I'm hoping to find an orphan set of DA or other USD 2 stage cans. Anybody have some?
|
|
|
Post by vance on Oct 20, 2018 10:45:14 GMT -8
The Trieste has a J valve assembly which had to be removed. The nylon parts inside the J mechanism on these always break down and crumble. Since no replacements are available, and if they were would just crumble, the whole setup is removed and a plug is installed. The Titan II has no J valve and it came plugged from the factory. I bought a plug for the Trieste from VDH.
You can see the factory plug in the picture of the Titan II in the previous post.
These regs have both an HP and a LP port, so they are very versatile regulators with provision for modern equipment.
|
|
|
Post by SeaRat on Oct 20, 2018 20:02:32 GMT -8
Vance,
Using the HPR second stage poppet has an advantage of not contending with the design defect of the original Trieste, in which the Venturi was too weak. I am interested in the results.
By the way, there is a J-valve work-around almost no one know about. AMF Voit made a third-party J-valve with almost the same parts, but the valve seat is not nylon, but rather a durable plastic. The valve is all-aluminum. I know this as some years ago I purchased one off E-Bay.
John
|
|
|
Post by herman on Oct 21, 2018 3:54:31 GMT -8
There is a lot more to this that you may realize. The HPR has different threads than the Voit. The Voit is 5/8-24 as opposed to 5/8-27 in the HPR. The HPR is held in by retainer screws that are in a different place than the one for the Voit so there is no way to secure the second stage in position without modifying something. You might could jam the HPR in but it's not a good idea, it might work but you may also damage one or both parts.....or worse it come out during a dive, either way, not a good idea. Also, the Voit body is designed to be centered in the cans as opposed to the USD which is offset by a good amount,plus the tabs on the cans are in the wrong place. You can't use USD 2 stage cans, the holes won't line up. The only option is to use cans designed for single stages and cut the hole larger, not the easiest thing to do straight without proper tools. There are other issues as well. Go to VDH and search for Pegasus. That is a project that Luis did that does what you are thinking about doing. There were 9 of those made, one of which I have. I made/modified the parts used in the project which is the reason I know the details of the threads and such. It turned out to be a great reg but it's not as easy as cutting a hole a little bigger and force fitting some parts.
|
|
|
Post by vance on Oct 21, 2018 8:42:03 GMT -8
Yes, I understand the problems, and have read the threads. I am thinking about various ways to correct the thread problem and will have to experiment on some old second stage holders. I am considering machining an insert, etc. I have the capability to do light machine work, so making a sleeve and drilling and tapping for retainer screws, etc., is not an insurmountable problem (Unless it just won't work!).
EDIT: There is very little meat to work with on the seat holder, and very little room to drill out the body to make an insert. A helicoil might work, but it'll be tricky.
As you say, the 2 stage cans are offset, and will put the yoke off center. While not optimal, it probably make little or no functional difference. Cutting a single stage can is not appealing to me for several reasons, but not because of the actual cutting. That I can do, but I don't like permanently modding vintage parts.
I will be thinking about this stuff, though, and will be experimenting. Thanks for your suggestions and help!
|
|
|
Post by vance on Oct 21, 2018 10:56:10 GMT -8
Looking at the Trieste can and a DA can, I noticed that the DA's second stage holder is quite close to the intake horn as is the Trieste's. It is true that the Voit design was meant to be centered, but the Voit can is much smaller than a DA can, so the orifice is nearly the same distance away. Centering the first stage body in a larger can will back the orifice away from the horn by a half inch or so. Not sure if that will have a huge effect on the venturi action, but it will probably lessen it by some.
Also, the HPR levers will be offset pretty far from the center of the diaphragm plate if the Voit body is placed in the center. The Trieste levers are centered over the body where a DA's levers are longer to reach center from the offset position. Putting a Trieste in the center of a set of FX cans works, but putting an HPR second in changes the geometry.
Healthways levers look to be offset on the diaphragm plate by 1/4-3/8", so it will work, but being centered is probably preferable.
I don't have a DA can with the valve body out. From what I can see, the appear to be 2 locating tabs on the can hole to align the body correctly. The Voit body has one cutout and the DA body has two. The Voit's cutout appears to be in the same place as one of the DA's. One tab would need to go, but it looks like it should fit with only one tab. Anyone have a picture of the 2 stage can hole?
I was able to remove the ring on a DA and see the tabs in the hole. There are two, and the Trieste/Titan body has only one. The Titan body doesn't fit perfectly in position with a tab removed and screwed down. Also, the Titan/Trieste bodies are taller, requiring a spacer to be installed between the body and the can to lower the lever. While these things need to be addressed, it still looks possible.
I have had some thoughts about modifying the threads on a DA/HPR seat holder. The DA holder I have is a bit meatier than the one that was on the Titan, so it might be workable for a sleeve. A few other ideas would be to cut the threads off the seat carrier and reduce the diameter a bit to make new ones in a JB weld "sleeve". Or, turn the threads off the seat carrier, drill the threads out of the bore, add an unthreaded sleeve, and drill some holes for metal ears to secure the seat carrier from the top ala DAs.
|
|
|
Post by nikeajax on Oct 21, 2018 15:48:58 GMT -8
Yes, I understand the problems, and have read the threads... Phil, I knew you knew what you were saying/doing there--BRAVO SIR! I also know the way you work, and the way you think (at times!): you love the challenge of re-engineering whatever it is you find, it's just your nature! JB
|
|
|
Post by vance on Oct 21, 2018 16:36:25 GMT -8
There is a lot more to this that you may realize. The HPR has different threads than the Voit. The Voit is 5/8-24 as opposed to 5/8-27 in the HPR. The HPR is held in by retainer screws that are in a different place than the one for the Voit so there is no way to secure the second stage in position without modifying something. You might could jam the HPR in but it's not a good idea, it might work but you may also damage one or both parts.....or worse it come out during a dive, either way, not a good idea. Also, the Voit body is designed to be centered in the cans as opposed to the USD which is offset by a good amount,plus the tabs on the cans are in the wrong place. You can't use USD 2 stage cans, the holes won't line up. The only option is to use cans designed for single stages and cut the hole larger, not the easiest thing to do straight without proper tools. There are other issues as well. Go to VDH and search for Pegasus. That is a project that Luis did that does what you are thinking about doing. There were 9 of those made, one of which I have. I made/modified the parts used in the project which is the reason I know the details of the threads and such. It turned out to be a great reg but it's not as easy as cutting a hole a little bigger and force fitting some parts. I am with you on these problems! I really appreciate the help and warnings about attempting this conversion. I do have a couple of other comments/questions/concerns: There is a pretty smart guy I know of who has done these conversions by "re-configuring" the threads on an HPR. While this is a brute force method, I can't really see how the second stage could possibly "come out" during a dive. The threads are definitely compromised, but even so, I don't believe they could fail under 150 or less psig. My idea of a smooth sleeve with retaining ears screwed to the body (sort of like the Dacor second stage attachment) is probably weaker than this would be. You could use ears or some other restraint system as backup retainers if you were worried.
The objection to the "get a bigger hammer" method is basically a machinist's distaste for "not right". I share this distaste, but sometimes "not right" is better than jumping through crazy hoops. The DA can will probably not work with even one tab in place. Leaving a tab causes the intake horn to be rotated too far up and the yoke is still twisted. But, the tabs are really not necessary if one is aware that rotation is possible under use. An alignment mark and maintenance would be sufficient to keep things straight. No alignment tabs will allow the body to rotate into a more efficient position. The offset definitely adds strange geometry to the mix!
|
|
|
Post by crabbyjim on Oct 23, 2018 5:34:50 GMT -8
Phil,
I think it's about time for you to reveal your relationship to Victor Frankenstein.
|
|
|
Post by nikeajax on Oct 23, 2018 7:34:54 GMT -8
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 23, 2018 12:54:43 GMT -8
Abby? Abby Normal!...I knew her quite well! Crush fit of two different thread pitch's only is good for one (maybe two) times removing or inserting again. I had that issue with my Colt 44sp SA. I had a extra barrel marked 44 win. (44-40) but the threads were 2nd generation.......different pitch than the gun frame...3rd generation. Gunsmith told me it could be crush fit into place but only good for one or two times removal.....ruining the frame and the barrel.
|
|
|
Post by duckbill on Oct 23, 2018 19:32:34 GMT -8
I had that issue with my Colt 44sp SA. I had a extra barrel marked 44 win. (44-40) but the threads were 2nd generation.......different pitch than the gun frame...3rd generation. Gunsmith told me it could be crush fit into place but only good for one or two times removal.....ruining the frame and the barrel. I'd live with the .44 Special marking, or have it restamped COLT FRONTIER SIX SHOOTER like the .44-40s originally were. No way I'd booger up a good frame of any generation.
|
|
|
Post by vance on Oct 24, 2018 8:09:56 GMT -8
I had that issue with my Colt 44sp SA. I had a extra barrel marked 44 win. (44-40) but the threads were 2nd generation.......different pitch than the gun frame...3rd generation. Gunsmith told me it could be crush fit into place but only good for one or two times removal.....ruining the frame and the barrel. I'd live with the .44 Special marking, or have it restamped COLT FRONTIER SIX SHOOTER like the .44-40s originally were. No way I'd booger up a good frame of any generation. I'm looking at using the second stage holder that came in it. I'm not sure what it is from, whether it was a factory installation, which I doubt due to the kludginess factor, or a user solution for a lost plug. It must be a Voit 2 stage holder, but I'm not very knowledgeable about Voit parts. Anyway, drilling the body for DA ears and using a stock horseshoe might be the simplest solution. Back in the day, Luis, Herman, and Michael (Creed) were working on a new second stage for this conversion. I know they made some, but only a few.
|
|
|
Post by herman on Oct 24, 2018 12:00:42 GMT -8
That is the correct Voit part, at least for the early Titans. There were 2 versions of the Titan II, the early one had a chrome outer cap and used the assembly you have. The later one used a black plastic cap and the plastic plug. There may have been some cross overs that I am unaware of and/or parts swapped during service over the years.
I have been mulling this over for a few days. Removing the threads from an HPR is going to leave you with very little material and opening up the hole in the body is going to take some careful machine work. Since the orifice is in there, you can't simply drill (or mill) it out. It will require a small boring bar and a boring head plus making some kind of jig to hold the reg. I don't see that as a viable option. Using a DA/RAM lever and standoffs will require some precise drilling to get the screws in the correct place, there is very little room for error since alignment is critical. That said, I think you could use the seat holder you have, assuming the height is OK, with the USD lever. The holes in the assembly you have will likely have to be modified to get the proper operation of the venturi. I don't recall how many are in that assembly or if they are in the correct place. Luis and I spent a lot of time and effort getting the correct placement and size of the holes in the Pegasus and HPR second stages. It's a lot touchier than you would think.
Depending on what machine equipment you have access to, IMO your best option is to duplicate the original Voit Trieste second stage and modify Conshelf seat holder and levers to work with it (what we did in the Pegasus with some modifications to the holes to tweak the venturi). That could be done with a lathe and a dremel tool although a mill will make things a lot easier.
|
|
|
Post by vance on Oct 25, 2018 12:10:55 GMT -8
That is the correct Voit part, at least for the early Titans. There were 2 versions of the Titan II, the early one had a chrome outer cap and used the assembly you have. The later one used a black plastic cap and the plastic plug. There may have been some cross overs that I am unaware of and/or parts swapped during service over the years. I have been mulling this over for a few days. Removing the threads from an HPR is going to leave you with very little material and opening up the hole in the body is going to take some careful machine work. Since the orifice is in there, you can't simply drill (or mill) it out. It will require a small boring bar and a boring head plus making some kind of jig to hold the reg. I don't see that as a viable option. Using a DA/RAM lever and standoffs will require some precise drilling to get the screws in the correct place, there is very little room for error since alignment is critical. That said, I think you could use the seat holder you have, assuming the height is OK, with the USD lever. The holes in the assembly you have will likely have to be modified to get the proper operation of the venturi. I don't recall how many are in that assembly or if they are in the correct place. Luis and I spent a lot of time and effort getting the correct placement and size of the holes in the Pegasus and HPR second stages. It's a lot touchier than you would think. Depending on what machine equipment you have access to, IMO your best option is to duplicate the original Voit Trieste second stage and modify Conshelf seat holder and levers to work with it (what we did in the Pegasus with some modifications to the holes to tweak the venturi). That could be done with a lathe and a dremel tool although a mill will make things a lot easier. Thanks, Herman! I will look into the Conshelf bits and machining a copy of the Voit second stage. I have been talking to Creed about this a bit. He is somewhat near me and his machinist may be amenable to making me some.
|
|