US Divers Metal second stages, Why not?

[HM_legon]

Hello SB,

I've recently been tinkering with a set of USD metal second stages, Conshelf supreme and deepstar 2, I got in a steal of scubamuesum.
These paired with a pair of conshelf se2 first stages I got when I first got into diving, I making a pretty sweet looking retro single hose set-up.
when I first got these two conshelf se2's they both had gauges, bcd hoses and second stages, but they were all the crappy plastic second stages cracked that they don't make anymore, so I sat them in my closet and got a newer used scubapro rig.
Now that I've dabbled in servicing the first and second stages, I'm curious why they stopped making these style of second stages? to me they seem to simple to mess up.
With my Scubapro mk2 set up I mentioned earlier, the shop near my college has,
broken the shell of my second stage,
gave it back to me like a steam engine
when I took it back, they gave it back to me, 2 hoses loose and it still makes the noise.

With this conshelf set, I've done all the servicing myself with youtube tutorials, an parts from online, and it works flawlessly.
on top of that, my home shop says they will not service the conshelf second stages anyway, saying something about Aqua Lung calling an end of life for those models.

also slightly unrelated, does anyone know if the exhaust t's off the newer plastic us diver seconds, fit on the older metal shells? I know the military contact ones look real similar to the seconds I have, and they take the exhaust T's that I have on all my old cracked plastic US divers seconds.

Is there something I'm missing, or does getting an older proven reg like the conshelf first and seconds, and working on it yourself for literately 1/10th the cost just make more sense?

Thanks,
Legon

 

[James79]

Legon,
You're not missing anything... I and my kids dive old metal regs (Conshelf and SP 108/109). Only real shortfall of them is that early USD seconds with the screw on T usually have a very small exhaust valve, leading to higher work of breathing.
Regarding the plastic USD regs, the early Conshelf plastics were notorious for cracking around the inlet fitting... But are parts interchangeable with the metal ones (internals, diaphragm, exhaust T). When I get one of them I generally just gut them for parts. The later plastic Conshelfs (like the SE3) still use nearly all the same parts, but the exhaust T changed (different flange on the main body of the reg). On the bright side, they don't crack as often so are more likely to be serviceable.
Also about exhaust Ts, I've designed both press on and screw on Ts for the metal Conshelfs that can be 3d printed in TPU... So if you tear a T it's not a deal breaker on those.

Respectfully,

James

 

[HM_legon]

Did you upload the files for the replacement T's anywhere? Or are you willing to share them? It would be nice to have some back ups, as the most decrepit part on these regs are the T's.

Thanks for the info!

 

[James79]

Did you upload the files for the replacement T's anywhere? Or are you willing to share them? It would be nice to have some back ups, as the most decrepit part on these regs are the T's.

Thanks for the info!

I haven't yet, but probably going to.

 

[lowwall]

I feel the same about Mares' metal-bodied downstream seconds. These are internally very similar to the later Conshelfs with the larger exhaust port except that the Mares have the VAD bypass tube which basically eliminates inhalation effort after the initial cracking effort.

Mares still produces the Abyss and service parts are available for both the Abyss and the compact metal Proton seconds.

 

[Green Frog]

Well, looks like another convert here! You might want to look at my posts from a little over a year ago when I discovered that a major shop was refusing to rebuild my Conshelf XIV due to "parts avaiability". I met lots of nice folks including especially @James79 and @rsingler who helped me get going on maintaining them myself.
My ideal rig is based on a Conshelf 22 first stage with the four LP ports, and the metal (1085) second stage from the C XIV, Aquarius, etc. BTW, is seems that somebody still provides the Conshelf 14 seconds, but only for "military or professional" use.
There are lots of us who still resist giving up our metal second stage Conshelf seconds and if you go back and look through the thread I mentioned you will also find good info about finding the parts needed for self servicing them.
Froggie

PS I went back and found the thread I mentioned, it is

Rebuild a Conshelf XIV

I stopped in at the nearest dive shop today in preparation for my first trip back to the Bahamas since COVID hit. I asked about having an “annual” service to my trusty old Conshelf XIV, but was told they are no longer supported and I can’t have that done. Is this true? Although my 14 is...

scubaboard.com

While you're at it, there are several other good threads about the 1085 seconds.

 

[USdiver1]

Yep, the key to eternal diving nirvana is found in the following metal second stages: US Divers Conshelf 1085, Voit MR12, Scubapro 108, 109 and 156 Balanced Adjustable, Mares MR12, Abyss, Proton. Easy to work on, simple designs, bulletproof reliability = SCUBA NIRVANA

 

[HM_legon]

I've seen multiple other post like this one, mention the smaller exhaust tees of older models and the increased effort of breathing. The two I've got have this older style two screw exhaust tee that makes exhaling more difficult than a modern reg. Is there a way I could retrofit an adapter or something to the screw hole to take the more modern 1085 style exhaust tee? I've got access to a good amount of these, as well as parts for the regs, so I don't want to just trash/shelf them because of the exhaust Tee.

 

[Green Frog]

@HM_legon, in a word, no. The later 1085 boxes are common and cheap enough that it just wouldn’t be worth the effort or cost. In the last six months I’ve gotten a couple of orphan 1085 boxes one in excellent shape, one needing a major overhaul, and paid less than a C-note total for both. Gotta love flea bay!

 

[James79]

I've seen multiple other post like this one, mention the smaller exhaust tees of older models and the increased effort of breathing. The two I've got have this older style two screw exhaust tee that makes exhaling more difficult than a modern reg. Is there a way I could retrofit an adapter or something to the screw hole to take the more modern 1085 style exhaust tee? I've got access to a good amount of these, as well as parts for the regs, so I don't want to just trash/shelf them because of the exhaust Tee.

It's not just the T itself, it's also the actual exhaust valve diameter (for most of them... Some screw on T 1085's have a larger valve). I'm generally not bothered by it, but I've seen a Kirby Morgan box that used a screw on flange for the press on T. I could try to model one up, or just model a screw on T to mimic the critical properties. Then if you want to get real tedious you can use a Dremel to open the exhaust spider to the larger size.

Respectfully,

James