Healthways SCUBA restore

[vance]

The interesting thing about the restrictors is the difference in thickness. The K is much thicker, and does not seem to work with the o-ring installed in the groove. I couldn't get it in that way, anyhow, and it came with the o-ring on top of it, not in the groove. This was also your discovery, way back in the Healthways thread from 2006, I think. The other one is a stamped sheetmetal button that has a relief for the o-ring to sit in, which causes little-to-no compression of the spring. This K-restrictor plus the o-ring will compress the spring quite a bit more. The springs in either one are seemingly the same, so what gives? Is spring compression/resistance not a factor in the breathing characteristics of the regulator?
Phil

[SeaRat]

Phil,

The spring compression resistance is not too much of a factor, but you may have the K-ristrictor in upside down. There is a depression for the spring to ride in, and there is not too much difference between that and the J-restrictor. They have a sealed O-ring so that none of the LP air can go around the sides. It really should slide in fairly easily, even with the O-ring. I am not sure, but it is possible that if the unit is ordered with the J-restrictor, they use a slightly heavier spring; I have never measured or heard of a different spring tension, however.

John

[vance]

That is true: the K has a machined depression for the spring I wasn't accounting for. The flat side of the restrictor goes up toward the sintered filter. But, the oring doesn't seem to work if it's in the groove like you do with the seat oring. And mine was assembled with the oring on top of the flat side, not in the groove.

[SeaRat]

I think you are right on this one. I just got my K-restrictor out of the plastic bag, and it has no groove for the O-ring at all. Now I have to take apart one of my regulators to look.

John

[vance]

Can you post a picture of the grooveless restrictor, please? Are you talking about the stamped sheet metal type like this one:

(Sorry about the picture through the greasy plastic ziploc bag!) Is yours the thick machined one but no groove?
Thanks,
Phil

[vance]

So there's an interesting discussion about the restrictors in JB's older Healthways double hose thread here: vintagescuba.proboards.com/thread/4155/healthways-dh-regulators?page=2  continuing on to page 3, which illuminates some confusion about this button.

There was a bit of discussion about where the oring goes in conjuction with the restrictor, but Mark, John, and JB were talking about two different parts. (There is a good picture of the sheet metal one in JB's pics of the Gold Label reg on this page, and a second one just under the Samurai poster. Compare this one to the one in my first set of pics above, not the plastic bag one.)

Here's Mark's question:

"The second O-Ring, by the filter and restrictor plate...does the O-Ring go on the groove of the restrictor plate?, or between the Rest. plate and the filter? It was in between when I first took it apart."


John's response:

"... the O-ring goes on the restrictor plate's groove, but between the restrictor plate and the sintered filter, so that it will seal.
"

(I'm assuming a typo, and he meant that the O-ring does not go on the groove, but between the restrictor plate and the sintered filter. This is where mine was.)

And JB's response:

"Mark, the o-ring goes between the filter and plate so that it is convex toward the filter (the sticky-outty part)
."

Because of JB's description and pictures showing his is the sheet metal one and Mark's description mentioning a groove like the machined one, I think this was the problem. 

Wow, talk about a lot of sound and fury over a minuscule  point.... However, this oring placement question caused me a lot of concern before figuring out the diagram, and seeing actual examples of the two different restrictors and where the oring was in the valve body.

Phil

[SeaRat]

Hi Phil,

I've looked at two regulators, the original SCUBA by Healthways and the second generation (double hose) regulator. They had different restrictors! My original had a restrictor as you described the J-restrictor, but with a tiny hole. My second generation had the larger button. Both had the O-ring on the top of the restrictor, then the sintered filter. It looked like the second generation had a longer threaded body too, perhaps to accomodate the increased depth of the button restrictor. Neither of the button restrictors have a groove for an O-ring. I'll try to get the photo I took posted here soon.

John

[vance]

So... I'm in the middle of an attempt to make silicone duckbills for the Scuba. I am going to try a version that will have liquid silicone applied or dipped over a one piece form. If that isn't satisfactory I'll go the extra mile building a two piece mold for a cast version. I watched some youtubes where liquid silicone is applied to a form in several coats, and the rubber seemed to come out smoothly and at a consistent thickness over a dome. It might prove difficult to get a uniform thickness over a more intricate form. I'm not sure if the consistency of the mixture will work for dipping the form into the silicone, or if I'll have to use some kind of applicator to spread the stuff on the form or a combination of both. Silicone is supposed to stick well to itself, so maybe spot applications will work to sculpt a uniform wall thickness. I ordered some silicone, and it should arrive soon.

I also had some thoughts about how to make a duckbill eliminator-type mushroom valve set up for it. The idea would be to make a plastic fitting that slips over the end of the exhaust horn, covering the extra exhaust drillings. It would have a flat plane on top, sitting on and overhanging the slanty part (sort of like a graduation cap) where the mushroom would sit. Then, to provide clearance for the mushroom, provide an exhaust airway, and a robust seal for the air chamber, a raised solid cover that replaces the exhaust diaphragm would be fitted.
I might try making this out of sheet metal and super sculpy to test its efficacy. Unless my duckbills are just too good. I'll keep you posted!

[vance]

If this all works out, and/or it's worth documenting, I'll start a new thread about Scuba exhaust mods.
Phil

[nikeajax]

Phil, I've been thinking about what you want to do too My though though is to make a form out of PVC pipe, but making it three pieces instead; one in the middle that would slip/pull out, thus allowing the other two parts more room to drop away/out, I think this would cut down on the creative verbiage

JB

[vance]

So, JB, that's really not clear to me. Could you do a graphic to illustrate? I'm not a graphics guy, but, I mought could draw something that might show what I have in mind.
I made wood forms for the duckbill. One is the inner, the other outside. They should fit together in a two part mold that leaves a 1mm wall thickness. BUT! My first attempt will be a dip attempt. I will show pics soon.

[vance]

OK, so here's the forms.

D


It might be evident that there is an inner and an outer form for a potential two piece mold to cast the part. However, I'm hoping that dipping/fussing might produce a viable part that has a fairly consistent wall thickness, without dealing with injection molding, etc.. That would be awesome. However, I'm sort of concerned that this won't be easy to accomplish. I'm also thinking of a sort of plunge mold where the smaller form is plunged into a mold made from the bigger form that is filled with liquid silicone. We'll see.... 

[vance]

Here's a couple of pics of the sheet metal orifice, to compare to the machined one. These are the only two types I've seen. Please post pics of variants!




on Flickr

Phil

[nikeajax]

Phil, what the heck is that bottom one?!?!?!? Ummm, is that even a real Healthways part? I've never seen anything like that...

Your top image looks like all of the ones I've seen: I make all of the holes larger in mine, as I prefer an SPG.

Gosh, those forms look nice. My wife is coming home tonight and I'll try to get an image up ASAP, maybe Monday?

JB

[tomcatpc]

The bottom two photos look exactly like the restrictor plate in my Healthways SCUBA.
Mark