Porpoise CA-1 regulator

[Fibonacci]

The tank to reg connection is a bullnose gas fitting same as an oxy welding cylinder... DIN has a flat end with captive o-ring.
Interesting it fits!
I’m trying to ID the external fitting on the manifold...
Looking at the design and materials available in the 50’s I’m sure the Porpoise breathes like sucking through a garden hose BUT it is an important bit of dive equipment history

 

[Fibonacci]

Both tanks now treated...

 

[АлександрД]

It's DIN boys

There is answer about outer thread of manifold for twin tanks
Thank you for information about Porpoise thread!
BUT! what kind of washer do you use for this connector? It looks not like standard DIN with o-ring sealing, but like sealing by teflon washer (or even without washer????? just cone sealing?)

I scanned Ted Eldridge's original sectioned drawing of the second stage

I`d found drawing of 2nd stage - it looks, like membrane has disk inside, and two rubber pins to attach it to the membrane:

Such type of disks used in first Soviet SCUBAs:

or

May be Porpoise membrane should have same hard disk for lever?

 

[Fibonacci]

Yep it certainly does have exactly the same disc as your pics... Part 5.
I’ve already modelled it just didn’t include in my screen shot.
The four ‘pins’ are created when the co-moulded rubber extrudes through the holes and help lock the disc in place.

 

[Fibonacci]

Quick update... was able to get some spares and tips from the very helpful guys at the Historical Diving Society (Asia Pacific) and use their special tool to remove the HP seat carrier.
Tanks now through top coat and in at the hydro station for testing... fingers crossed!
Top coat on the first and second stage bodies... I used satin finish engine enamel, air dried then baked in a low oven at 60C.

 

[Fibonacci]

Bit more info on the ex-WWII twin tanks, seems they were marketed by Sea Hornet back in the day.
Here's an ad from the 1960-61 Mick Smith's Sports Store catalogue, also featuring their CO2 powered speargun... the twin tanks were gone by the 1963 edition, maybe they ran out of ex-military surplus stock?

Sadly the CO2 spearguns (and powerheads) were classed as a firearm under Australia's new draconian laws introduced in 1996 so apparently all remaining half assembled stock and spares were dumped in landfill.

 

[Sam Miller III]

Fantastic find! Fantastic restoration ! Enjoy following your progress

"Sadly the CO2 spear guns (and powerheads) were classed as a firearm under Australia's new draconian laws introduced in 1996 so apparently all remaining half assembled stock and spares were dumped in landfill."

Co2 powered guns are also illegal in Mexico and have been for many years.

It was the late great Bill Barada who developed the CO2 gun in 1935 in Los Angeles They can be home built from tubing and a CO2 cylinder-- I made one in 1955 and still have in hanging in my dive locker

There were three different brands of CO2 cartridge guns made in US were popular during the 1950s in US but soon lost their popularity due to cost of CO2 cartridges.

The Aussies developed and produced "Bang sticks." Power heard were products of California divers, used for spear fishing
There is quite a difference

Keep up the good work ! ( and keep on posting)

Sam Miller, 111

 

[Fibonacci]

Thanks for those kind words Sam, it has been quite a challenge to restore the Porpoise but interesting how many are still around in Australia! One guy I met through HDS had another 9 nearly complete waiting for parts...

Made up a special tool to install the front cover, an old bicycle hub tool was perfect for the task, just bored out the centre, tapped and fitted the three screws at 120 deg spacing, with a bit of plastic tube over the threads so they don't gall the softer brass cover or score the diaphragm underneath.

I spent today 3D modelling the safety strap, every example I've seen is perished or distorted in some way but I think I am close to getting it correct... will investigate getting some remade as either RP or soft tooled.

I went to a very interesting launch of a new 3D Rapid Prototyping technology by 3D Systems the other day... they can now offer limited production runs in high strength material (incl a 65A Duro elastomer with a smooth finish) or even grained in a few patterns!

The industry’s first scalable, fully-integrated 3D printing platform with ultra-fast speed enabling throughput improvement up to 15x and up to 20% lower parts cost.​

The examples they showed looked like they had come straight off-tool, unlike most RP parts which have some striations even at the finest (and very slow) settings.
This may be a real breakthrough for those interested in vintage SCUBA restoration!
Figure 4 | 3D Systems
Figure 4 Standalone 3D Printer Materials | 3D Systems

 

[happy-diver]

Brilliant thread Fibonacci

Hey I was talking to Mel Brown recently and he suggested
Tony Gregory had some diaphragms and exhaust valves made
and a possibility of safety straps but probably not, I haven't taken it further

What a first stage tool, a previous owner of mine used stillsons to open it
I got it brazed and lathed and chromed can't remember how I put it on

Hey do you have access to another length of ribbed hose

I'll put my hand up for six of your safety straps

Do you want a hand financing them

 

[Fibonacci]

Hey I was talking to Mel Brown recently and he suggested
Tony Gregory had some diaphragms and exhaust valves made
and a possibility of safety straps but probably not, I haven't taken it further
~snip~
Hey do you have access to another length of ribbed hose
I'll put my hand up for six of your safety straps
Do you want a hand financing them

Already had a chat with Tony... he is Porpoise King

Yep, he had some diaphragms made up some time ago off an old aluminium ex-NZ tool but they don't actually fit properly, and won't function. There are subtle differences between original and late model Porpoise diaphragms so I have been working with him and the HDS to redesign them correctly as well as do the mouthpieces, safety straps and exhaust valves.

I only have one length of the correct ribbed hose for this project but Tony assured me they were just lengths of CIG welding set black oxygen hose... sure enough, peering closely at the original hose it is still faintly marked with the CIG logo.

Got enthused and also modelled new front covers and diaphragm plates

Many thanks for the offer re financing, at this stage the HDS has first option on what they want to do regarding spares kits and limited production runs... RP vs tooling will depend on expected volume, as will unit price so I will get some quotes and see where that leads.