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Calypso IV Freeflow

Posted: Mon Mar 02, 2020 6:22 pm
by ScubaLawyer
I started asking questions about this issue in another thread a while ago but sort of lost where I was. Anyway, for the first time I have encountered the following FREEFLOW problem in my rebuild of a USD Calypso IV (non J-Valve) reg.

IP is fine (and I have actually experienced the same problem described below at varying IP’s). 2nd stage adjusted normally. 2nd stage lever is not caught on anything and moves freely, always popping back up into place when manually depressing it. HOWEVER, when diving with it I will inhale and on occasion it will get stuck in lever down position and freeflow. When that happens, nothing I can do will stop the freeflow - not pushing on the purge button, not exhaling forcefully, not taking the 2nd stage out of my mouth and moving it up and down in the water column or even banging it on my arm. Just solid freeflow. I’ve adjusted and re-adjusted but still the same thing - and only on this 2nd stage (I tried a different 2nd stage on the 1st and zero problem). Parts all look good. I’m at a loss. Happy to have someone show my ignorance. :) Mark

Re: Calypso IV Freeflow

Posted: Tue Mar 03, 2020 9:39 am
by antique diver
That's a tough one. Suspects include the lever shape at the lifting end, and being certain that someone has not substituted the wrong lever. The stem may be dragging in its bore due to a burr or bend in the stem or bore. Some anomaly in the diaphragm maybe. I would change all those out and see what happens. Can you reproduce the free flow on land or only underwater?

Re: Calypso IV Freeflow

Posted: Tue Mar 03, 2020 10:12 am
by ScubaLawyer
antique diver wrote:
Tue Mar 03, 2020 9:39 am
Can you reproduce the free flow on land or only underwater?
Only underwater. I'm convinced it's possessed by an evil sea demon. Gonna break it down. and see if I can determine anything..

Re: Calypso IV Freeflow

Posted: Tue Mar 03, 2020 10:20 am
by antique diver
I didn't mention lever height. I think the specs call for the air to just start hissing when a straight-edge is laid across the open can and lever tip. That's pretty much how I set them. There should be a little free-play in the lever with air pressure on... but you probably know all that. If it makes you feel any better I have had a similar problem with an older model MR12.

Re: Calypso IV Freeflow

Posted: Tue Mar 03, 2020 11:32 am
by ScubaLawyer
antique diver wrote:
Tue Mar 03, 2020 10:20 am
I didn't mention lever height. I think the specs call for the air to just start hissing when a straight-edge is laid across the open can and lever tip. That's pretty much how I set them. There should be a little free-play in the lever with air pressure on... but you probably know all that. If it makes you feel any better I have had a similar problem with an older model MR12.
All good info Bill. Thank you. And no, it does not make me feel any better but I appreciate the empathetic ear. :-)

Re: Calypso IV Freeflow

Posted: Fri Mar 06, 2020 10:48 pm
by h2operations
Mark,
I am suspecting, like Bill, it is either your diaphram or in the lever. You mentioned that there were no burrs. How often does this happen? Does this happen at any specific depth or draw volume ?

Re: Calypso IV Freeflow

Posted: Fri Mar 06, 2020 11:57 pm
by ScubaLawyer
h2operations wrote:
Fri Mar 06, 2020 10:48 pm
How often does this happen?
Any time I am underwater
Does this happen at any specific depth or draw volume ?
Now that you mention it, I only get a catastrophic gas loss event forcing me to abort my dive following an ESA on days with spectacular visibility, zero current, a bazillion large lobster walking around and warm So. Cal. water. :) Oh yea, and only when I inhale.... Seriously, I have no clue what the problem is, but I have yet to tear down the 1085 2nd stage.

Re: Calypso IV Freeflow

Posted: Sat Mar 07, 2020 2:22 pm
by h2operations
I know that was a strange question and your answer even better. I am curious if it is a 3 part combo. Many moons ago when the waters were clear and the skies were blue, I saw this on another device. The lever/spring and diaphram got into a position at depth that they could not bounce back into position due to the flow pressure. The flow caused basically a suction as it went past the diaphram. This goes back to Bill questioning if it has a original parts?

Re: Calypso IV Freeflow

Posted: Sat Mar 07, 2020 3:07 pm
by antique diver
h2operations wrote:
Sat Mar 07, 2020 2:22 pm
I know that was a strange question and your answer even better. I am curious if it is a 3 part combo. Many moons ago when the waters were clear and the skies were blue, I saw this on another device. The lever/spring and diaphram got into a position at depth that they could not bounce back into position due to the flow pressure. The flow caused basically a suction as it went past the diaphram. This goes back to Bill questioning if it has a original parts?
Grasping at kelp here, but Paul's comment made me think of the somewhat remote chance that there is something abnormal about the shape, size or positioning of the venturi passage in your second stage. I know it's not likely, but you should closely compare the internals of the problem 2nd stage with another one of same make if you have one.

I am assuming that there is a Silicone diaphragm in this, but if not switch to that or try a different one. I have plenty of those if needed. Also levers. And be sure you have all the proper type washers on lp stem in the correct positions. You do have a good parts schematic of that?

Re: Calypso IV Freeflow

Posted: Thu Mar 12, 2020 5:19 pm
by Ron
This is anecdotal, but I've seen stacked tolerances for the length of the poppet and the shallowness of the lever do this. It only happens when the lever is very far down during a deep inhalation. Here is a bad picture indicating what I am describing. I've seen this twice with a long poppet and a short lever.
snip.JPG
you can check this manually with the reg open and see if there is any poppet and lever interference when the lever is depressed almost maximally. During deep inhalation the lever will intersect the threaded end of the poppet and it will snag there and hold open, causing a freeflow.

Re: Calypso IV Freeflow

Posted: Thu Mar 12, 2020 6:05 pm
by ScubaLawyer
Ron wrote:
Thu Mar 12, 2020 5:19 pm
This is anecdotal, but I've seen stacked tolerances for the length of the poppet and the shallowness of the lever do this. It only happens when the lever is very far down during a deep inhalation. Here is a bad picture indicating what I am describing. I've seen this twice with a long poppet and a short lever....
Thanks Ron,

I get what your are trying to say (although the drawing did appear somewhat pornographic at first glance :) ).

I'll check it out.

Mark

Re: Calypso IV Freeflow

Posted: Fri Mar 13, 2020 2:57 pm
by Ron
Yeah my lever is admittedly a little dong like. I'm no artist :lol:

Re: Calypso IV Freeflow

Posted: Fri Mar 13, 2020 4:17 pm
by antique diver
I won't even try to draw the parts mentioned below for fear of it looking suggestive to certain people: :roll:

Look at a repair or parts manual showing your second stage, and be sure that you have the thick spacer in the proper location on the poppet stem.

Re: Calypso IV Freeflow

Posted: Sat Mar 14, 2020 3:07 pm
by Ron
To Bill's point I've screwed that same thing up before. You have to have the thick spacer, thin washer, and nut or it won't work correctly. You get a sloppy loose lever or freeflows.

Re: Calypso IV Freeflow

Posted: Sat Jun 13, 2020 7:09 pm
by ScubaLawyer
Ok, I finally downed a couple of single malts and tackled my free-flowing 1085 2nd Stage again.

Turns out Ron was correct! The "sweet spot" for cracking pressure placed the end of the poppet right at the curve of the lever. When I fully depressed the lever it just stayed depressed because the lever caught on the end of the poppet.; ergo, freeflow. I had not been able to reproduce it on land before but this time I did. See Pic. I ended up with the end of the poppet just past the curve of the lever so when fully depressed the lever can't go all the way down. I guess I could have left it where it was and used a dremeI to shorten the end of the poppet. I put a new 5-40 locking nut on and cleaned up the case and it seems to breath fine now. Thanks Ron and all for your assistance. Mark.

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