Open source rebreathers - an alternative approach

Crazyduck

I thought about that myself.
I figured if it came down to that- I would cut off the bottoms and glue on drybag flaps and clips. That way I could reach into the countlung to make modifications and easily seal it for testing purposes.

Finding an ultasonic welding or RF welding- yikes that would be fun.

Andrew

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Howdy Senor- What’s Happening!
Rob Davie April 2005-

Presently in a state of transition from Open Circuit to Closed Circuit.

"You will not be punished for your anger; you will be punished by it." - Buddha.

onetime

In the past I've located a few but never went beyond that as other priorities tend to get in the way.

whoizrob

involving the evolution of the tr300 talked about using thing pond liner material and some sort of vulcanizing glue. Sounded promising but I have yet to make it down to the local supply shop to take a look... Might be worth looking at as an alternative to ultrasonic welding...

Rob

teomannaskali

I was thinking of using motorcycle inner tubes.

Would anyone have any idea on what glue works?

I have tried several wihout success. It helps if you first sandpaper the parts that you are planning on glueing.

Someone recommended locktite GL3. Havent tried it.

I have made Aluminum clamps that hold the seal the counterlungs. This helps easy development.


Teoman

teomannaskali

I can have stuff really easily made out of neoprene. just for your info.

If anyone would have any parts to trade I would be more than happy.

Maby even counterlungs....

Teoman

montyg

We use http://www.arkinflatables.com for RF welding. They make really neat stuff, including DSMB's.

The RF welded RIB pontoons they make can be pumped up to 4 bar, where everything else comes apart over 1 bar ...

They make dry bags too, but why bother if it can be RF welded?

rgds
monty

montyg

I have access to HDPE pipe, rod and sheet (I supplied some to Karl - the pipe is cheap, it's the shipping cost from South Africa which is a bummer)

If we do it in quantity and ship it more economically (ie not DHL/UPS) I do not foresee a problem.

I'll find out about the 8" piece today. The company I buy it from is here: www.emplast.co.za (not the coatings and lining division, the engineering division) and the other great news is that they are set up to weld HDPE, too!

rgds
monty

montyg

They have HDPE pipe with OD greather than 8". Let me know what wall thickness you want ;-)

The specs are in a PDF here:

http://www.petzetakis-africa.co.za/d...dimensions.pdf

These guys will sell me off-cuts but they just told me who their supplier is :-)))

Greece - http://www.petzetakis.gr/
Italy - http://www.induplas.it/
Romania - http://www.petzetakis.ro/
Spain - http://www.flexiplas.es/
Portugal - http://www.heliflex.pt/
United Kingdom - http://www.eurohose.co.uk/
Germany - http://www.heliflex.de/
Africa - http://www.petzetakis.co.za/

rgds
monty

GKAM

I have used bike inner tubes on an old Rebreather DIY project. It works but it takes ages to get rid of the rubber smell and taste.



The glue I used is a local brand available in tyre repair shops. Dirt cheap stuff and (I bet) very carcinogenc.

Having studied more now, I would be very reluctant to use inner tubes and the associated glues on CLs.

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GKAM

New gas pipes are being installed in Greece all over the place now, so HDPE is abundant and cheap.

Petzetakis is rakeing it in right now! There are off-cuts lying around in every work site. All you have to do is ask for one of the workmen to let you take one for free. ID/OD and thickness ranges from canister size to SS DPV.

Mind you, HDPE can only best be used for a tube and that's that. Unlike acetal (Delrin) it cannot be processed on a lathe or CNC very well.

HTH
/George

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