Forum rules
Discussion of diving methods and equipment available prior to the development of BCDs beyond the horse collar. This forum is dedicated to the pre-1970 diving.
User avatar
SurfLung
Master Diver
Posts: 1700
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Improved Trieste Diaphragms!

Wed Jan 19, 2022 4:48 pm

Newly Designed Diaphragms for Trieste Regs
- James and AntiqueDiver have been working on a better diaphragm design for the Trieste Double Hose Regulator. James is producing it and AntiqueDiver has been testing it. Here's what it offers:

1. Easier breathing - It's not a dome design so it compresses easier.
2. It's Made of Silicone - More sensitive and long lasting.
3. Sized correctly to fit the ridges in the Trieste cans... Easier to install and more secure.

They're finished with development and testing and are offering these for sale now. I got my order in this morning.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

User avatar
couv
Master Diver
Posts: 447
Joined: Tue Jul 18, 2006 10:26 pm

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 12:08 am

Thanks Eben,

I'm looking forward to hearing more about them.

I don't own a Trieste, but I'm very interested in the DIY process required to generate a part like this.

c
A sincere THANK YOU to all at VDH who make this wonderful resource available and to all the thoughtful contributors.

User avatar
ScubaLawyer
Master Diver
Posts: 1597
Joined: Thu Apr 08, 2010 11:25 am
First Name: Mark
Location: Laguna Beach, CA

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 10:58 am

I have a Trieste diaphragm coming from James as well. Combined with my super-stealth skunk-works modded dual venturi-adjustable Trieste 2nd stage Bill T built for me a while back I'm looking forward to having a Trieste that actually works well! :)

I shall report back after a test dive!
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

User avatar
rhwestfall
Master Diver
Posts: 594
Joined: Thu Jan 16, 2014 2:34 pm
First Name: Robert
Location: "La Grande Ile"

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 2:06 pm

Perhaps I can now get my Trieste(s) going....

where/how does one go about procuring such item?
Bob

No Longer Awaiting my Kraken.....

James
Lung Diver
Posts: 68
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 2:44 pm

rhwestfall wrote:
Thu Jan 20, 2022 2:06 pm
Perhaps I can now get my Trieste(s) going....

where/how does one go about procuring such item?
Message sent!

reddiver
Lung Diver
Posts: 64
Joined: Tue Mar 08, 2011 11:10 pm
First Name: David
Location: Youngsville,NC

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 9:23 pm

I would also be interested in the new diaphragm. I have a Trieste but it is not a good breather.
Please send contact info.

James
Lung Diver
Posts: 68
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 11:34 pm

reddiver wrote:
Thu Jan 20, 2022 9:23 pm
I would also be interested in the new diaphragm. I have a Trieste but it is not a good breather.
Please send contact info.
Message sent

User avatar
antique diver
Master Diver
Posts: 2149
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: Improved Trieste Diaphragms!

Thu Jan 20, 2022 11:44 pm

Hey James! I told you there might be one or two Trieste owners taking an interest in your new diaphragm!
The older I get the better I was.

James
Lung Diver
Posts: 68
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: Improved Trieste Diaphragms!

Fri Jan 21, 2022 10:36 am

To save time/effort if anyone else is interested, here is Antique Divers bench test data from the development process:
Image
Version 1.0 is the final version, and to clarify on the destructive tests it took intentional abuse to start separating the friction plate.
Friction plates are printed ABS plastic, with a quick sanding to smooth them, but there is a bit of a grain still... recommend installing with the lever parallel to the grain.
I ask $25 each (plus actual shipping), and can approximate colors of silicone (clear silicone with mica powders added for color) and have a few colors of ABS that I can print the friction plates in. It is a hobby, and I only made 2 molds.... combine that with long cure time on the silicone and it's not a fast process. Partly due to that, and partly because cash up front makes it feel like a job, payment is only accepted after parts are received and your happy with them.
Fastest way to reach me is via the "Email member" button in the forum (I check email regularly).

Respectfully,

James

User avatar
simonbeans
VDH Moderator
Posts: 1010
Joined: Sat Jun 25, 2005 2:00 pm
First Name: Allan
Location: Rochester NY

Re: Improved Trieste Diaphragms!

Fri Jan 21, 2022 12:44 pm

Your diaphragm is indeed a very welcome aspect to true vintage diving. I do have a word of advice. Seeing as how you have now sort of advertised your product and that you may not know a buyer personally, I would do something for your own protection. The most you could do is become a LLC or Corp. LLC is less expensive. Or at least have a written limit of liability that the buyer must sign prior to the sale. One accident that might (God forbid) occur with the regulator with your diaphragm and the lawyers get a feeding frenzy. With a LLC, the most they can get is the assets of the "company" otherwise you and what you have is open for "feeding". Just my opinion.
Check out my website: www.vintagescubastuff.com

James
Lung Diver
Posts: 68
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: Improved Trieste Diaphragms!

Fri Jan 21, 2022 3:39 pm

simonbeans wrote:
Fri Jan 21, 2022 12:44 pm
Your diaphragm is indeed a very welcome aspect to true vintage diving. I do have a word of advice. Seeing as how you have now sort of advertised your product and that you may not know a buyer personally, I would do something for your own protection. The most you could do is become a LLC or Corp. LLC is less expensive. Or at least have a written limit of liability that the buyer must sign prior to the sale. One accident that might (God forbid) occur with the regulator with your diaphragm and the lawyers get a feeding frenzy. With a LLC, the most they can get is the assets of the "company" otherwise you and what you have is open for "feeding". Just my opinion.
As much as I hate the necessity, I believe you are right. I'm now working on generating a general liability release that I'll ask people to sign and send back (via email). Not that I think it will come into play, but to protect my my family in the event it ever does.

Further, anyone buying handmade/home made parts for their regs should (and if they don't, it's now made clear) understand the potential for failure/defects and that they are doing so at their own risk!

Respectfully,

James

User avatar
SurfLung
Master Diver
Posts: 1700
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: Improved Trieste Diaphragms!

Wed Feb 16, 2022 4:12 pm

First Impressions - Dive Report
- I finally got to try my new Trieste Diaphragm underwater and I'm pleased to report, it's a huge success. Rich and I went to the public pool last Sunday... Max Depth 12 feet ... To do a comparison test between my new diaphragm equipped Trieste and three other double hose regulators.
- First is my new diaphragm Trieste... I dove it like I was just going diving with any of my DH regulators. My impressions are as follows. Very smooth and effortless inhaling. Actually quieter than expected. I swam a couple of underwater laps while kicking hard with my fins and never felt out of breath or any excess breathing effort. I don't have instruments to measure but the ease of breathing with the new diaphragm puts this regulator into the realm of a regular go-to Double Hose Regulator right alongside my favorites.
- Second was Rich's Trieste which was re-built by Greg Barlow and with the Dome Shaped replacement diaphragm that has been the only option until now. This regulator felt fine for the first 5-10 breaths. But as the dive progressed I could tell it was requiring significantly more effort to inhale. And it was more and more noticeable as my breathing muscles got more fatigued. Rich calls it a "Wall Hanger" because of the excessive breathing effort. I think we'll put a new James and Bill Diaphragm in it and turn it into a breather.
- 3rd was my Voit Navy... I figured that would be good to compare with these two Voits. My NAVY is tuned up and breathes super nice. And I think my Trieste with the new diaphragm was very close to the same breathing effort. I know it was not BETTER than the Navy but it was just as easy or awfully close.
- 4th was my Snark III... This one was a little difficult to judge. The Snark III was making alot of airflow noise like a Mistral and behaving a little erratic... like it wanted to free flow if I took too fast of a breath. By comparison, the New Diaphragm Trieste breathed quieter and smoother. Probably not a fair comparison with the Snark III acting strange as it was.
- 5th... Along with the new diaphragm, I ordered a 2-piece band clamp. This clamp makes it much easier to install a new diaphragm nice a straight and centered... Something very difficult with the original 1-piece band clamp.
Image
Image
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

James
Lung Diver
Posts: 68
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: Improved Trieste Diaphragms!

Wed Feb 16, 2022 10:48 pm

Folks, I need to issue an advisory.

Short version: With a new style Scuba Museum duckbill, and this new diaphragm, a failed intake non-return in your mouthpiece can cause impeded or blocked exhale. It is not a major safety issue, in that you would the exhale around the mouthpiece. In the meantime, the old style flat duckbill does not have this interaction. I will work on a solution to this unforeseen failure mode, and update as I go.

Longer version: In Surflung's installation and testing process he experienced an issue that neither I nor Bill could reproduce... on exhale he would get unusual resistance up to and including complete blockage. Some troubleshooting later, replacement of his intake non-return solved the problem. Both Bill and I set out to recreate the issue ourselves and couldn't.... but we did notice Surflung has the new, formed, Duckbill from the scuba museum while bill and I both have old style flat Duckbills. I now have a formed Duckbill on hand, and can recreate the exhaust lock up (only by removing my intake wagon wheel). I will be working on a solution to eliminate this failure mode, and will advise as I go. Regardless of what it takes, I'll get the fix to everyone who has one once it is sorted.

Respectfully,

James

User avatar
SurfLung
Master Diver
Posts: 1700
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: Improved Trieste Diaphragms!

Thu Feb 17, 2022 12:13 pm

Duckbill Failure
- I didn't want to make a big issue of the duckbill because I think it's a failure of the duckbill and not the diaphragm. And I've experienced failures of duckbills in the past having nothing to do with the diaphragm. And besides, the problem was resolved satisfactorily... My Trieste is inhaling perfectly with the new diaphragm and exhaling perfectly with the new formed style duckbill.
- Back Story... We all know how goofy it is to slip the exhaust hose over the cuff of the duckbill on the exhaust horn. Usually it doesn't seem to matter if you end up with it twisted a little. But there's not a lot of room inside the Trieste can and my first couple of tries must have got it twisted enough to cause interference and blockage on exhalation. I spoke on the phone with Bill while troubleshooting and we came up with two possible causes and solutions. And unfortunately, I corrected both of them at the same time... So I don't know which was the actual culprit.
- Mouthpiece Valve Leakage... The possibility that the inhale side wagon wheel was leaking back pressure into the regulator and slightly inflating the diaphragm to cause interference with the duckbill was discussed. I disassembled the mouthpiece and checked the valve but it seemed to seal up just fine. These wagon wheel valves are nearly brand new but they are the flat style rubber because I was trying to be authentic Voit gray colored. Even so, I replaced them... Wagon Wheel and valve with the new mushroom shaped valves.
- Duckbill Fit and Alignment... Bill suggested I get the duckbill and hose installed with the can open so I could be sure that the duckbill was not twisted or impinged in any way. So I did this. Checked for free exhalation through the mouthpiece and it was fine. Reassembled the cans with the new diaphragm and this time exhalation was totally free and clear.
- So, which was it? The new mouthpiece valve or the correct alignment of the duckbill?

Thin Style Duckbills Arent't Perfect Either... I have had a thin duckbill cause exhaust blockage. It was on a Mistral and it happened after a free flow while practicing buddy breathing. Somehow the thin duckbill got sucked back into the hose. After that I started gluing the thin duckbills onto the backside of the can.
- And in fact this Trieste we've been working on came to me with a thin duckbill and it was kind of difficult exhaling. When I opened it up it had one of Bill's hand made diaphragms... Which explained why it breathed pretty decent... But the thin duckbill was actually folded lengthwise... which would explain the difficult exhaling. And this is why I replaced that duckbill with the new Formed duckbill.

So now we have seen issues with all three... DB Eliminator, thin DB, and Formed DB. Do we have to accept a crappy diaphragm just so our duckbills will work when they're not installed properly? Or, do we just need to be as careful and precise with our duckbills as we are with all of the other components?

Sorry for the rant. - Eb
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

User avatar
SurfLung
Master Diver
Posts: 1700
Joined: Sat Jan 01, 2011 2:03 pm
First Name: Eben
Location: Alexandria, MN
Contact: Website

Re: Improved Trieste Diaphragms!

Tue Feb 22, 2022 4:25 pm

Trieste Diaphragm Comparison
- When I opened up my dive buddy Rich's Trieste, I was pleasantly surprised to find it has an original factory rubber diaphragm that's in excellent shape. Pictured below from left to right are: The original factory diaphragm, the silicone reproduction diaphragm, and the new James and Bill designed silicone diaphragm.
Image

Things to Note:

1. The original and the rep-pro silicone diaphragms are convex (dome) shaped. The dome shape is an arch. Arches are strong and resist compression. And this is given at least part of the blame for the Trieste being a hard breather.
2. The re-pro silicone is identical to the original rubber except it is slightly smaller. This causes the ridges on the out edge to not fit the grooves on the outer edge of the can. And that makes it extremely difficult to install without it slipping out of alignment with the cans.
3. The new James and Bill design is concave shaped... The opposite of a dome. This shape is designed to compress and in fact it does so easily.
4. The new James and Bill design is also the correct size... So the the ridges on the outer edge fit the grooves in the can perfectly. Much easier to install and more secure after installing.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

Return to “Classic Vintage Diving”

Who is online

Users browsing this forum: No registered users and 15 guests