The Association of Model Submariners.

Would you like to react to this message? Create an account in a few clicks or log in to continue.

* THE FORUM FOR ALL THOSE INTERESTED IN BUILDING AND OPERATING MODEL SUBMARINES *



Join the AMS - Registered Forum users can become members of the AMS and it's free ...... To join send an email with your name , address and phone number to amstreasure@googlemail.com


For a guide to past events see the "Shows and Events" section.
Bournville MBC on Sunday 11th August 2024, 10.00 i
::::

Papplewick Pumping Station Sub Weekend, 14th & !5th Sept 2024

P~~~

$$$

Who is online?

In total there are 2 users online :: 0 Registered, 0 Hidden and 2 Guests

None


Most users ever online was 180 on Tue Nov 05, 2019 6:03 am

Latest topics

» David Forrest's R class
bladder systems EmptyFri Jul 19, 2024 1:00 pm by david f

» Futaba -868/915mhz equipment
bladder systems EmptySun Jun 09, 2024 10:47 pm by tsenecal

» Darnell type 21 submarine, need some help
bladder systems EmptySun Jun 09, 2024 9:35 am by Deep Diver (Fred)

» Robbe Seawolf V2
bladder systems EmptySat Jun 01, 2024 1:15 am by geofrancis

» bladder bags
bladder systems EmptyTue May 28, 2024 8:30 am by Deep Diver (Fred)

» WW2 mini sub build
bladder systems EmptyWed May 22, 2024 8:10 am by david f

» Peral Submarine of 1888
bladder systems EmptyMon May 20, 2024 1:00 pm by david f

» U-Boat R/C?
bladder systems EmptySun May 19, 2024 11:02 am by stig58

» Cheap Arduino Auto leveler
bladder systems EmptySat May 11, 2024 6:53 pm by 17b

Statistics

Our users have posted a total of 12476 messages in 1986 subjects

We have 1017 registered users

The newest registered user is Bazdiving

4 posters

    bladder systems

    avatar
    SimonH


    Posts : 92
    Join date : 2020-09-29
    Location : Nottingham, UK

    bladder systems Empty bladder systems

    Post  SimonH Sun Dec 05, 2021 8:52 pm

    Hi folks, 'm starting to think about the bladder now I can see the end of the WTC with its peristaltic pump so and thinking about the bladder.
    A lot seem to use a cut down cuff from a blood pressure meter, but since I new a longer thiner bladder I think to fit I was thinking about a length of bicycle inner tube. In theory the pressure differential should be zero apart from possible over inflation at the surface as far as I can see.
    I don't want it too long or I can see the same stability problems as with a long thin water ballast tank, but removing the valve core and with and adapter it should connect quite nicely with the air pump.
    Originally I intended to have a seperate air reciever but for simplicity I might just use the WTC which as it is large vs the bladder the change in pressure should not be too great. I'm a bit bothered that the silicon tube type control rod seals might act as a valve venting air out or that excess pressure might pop out the shaft seal (though it will have a keeper fitted) but I've not seen that mentioned as problems anywhere.
    In theory as the WTC pressure increases the external pressure should also increase as the boat dives, but I doubt they'll keep in step!
    Has anyone tried an inner tube as a bladder?
    avatar
    Tom(ADMIN)
    AMS Forum Owner


    Posts : 3026
    Join date : 2010-11-05
    Age : 64
    Location : Nevada, USA

    bladder systems Empty Re: bladder systems

    Post  Tom(ADMIN) Mon Dec 06, 2021 11:34 pm

    It has been done. The pressure you build up is minimal, however, make sure your endocarps are secured somehow. Those can pop off.

    david f likes this post

    david f
    david f
    AMS Treasurer


    Posts : 2406
    Join date : 2010-11-10
    Age : 73
    Location : Cumbria

    bladder systems Empty Re: bladder systems

    Post  david f Sat Dec 11, 2021 11:24 am

    Bike inner tubes have been used in the past (but not by me I have only used medical type bags.)

    The problem was, I think, sealing the cut ends.

    I happened to see that Norbert Bruggen offers a bag (which I think you can cut and glue). It is charmingly called a Gummisack in German! His product may give you some ideas.

    I think I saw elsewhere ? that you were thinking about using a float and fishing line distress indicator. I am feeling my age because I remember thinking, several decades ago, that was not a very good  idea (float buoyancy, friction, water depth, angle of wreck) hence the various types of Pinger.

    However I seem to be the only person using these bladder systems 1f626 and most people in model subs seem to only sail in clear, shallow water! Which seems a shame because it is so rare (in the muddy UK anyway.)

    Lovely work on your "WW2 mini sub" by the way bladder systems 1f603

    David
    avatar
    tsenecal
    Guest


    Posts : 314
    Join date : 2015-04-01

    bladder systems Empty Re: bladder systems

    Post  tsenecal Tue Dec 21, 2021 3:35 pm

    being an owner of one of norbert's delta submersibles, i am quite familiar with his pump/bladder systems. the bladder is made out of a sheet vinyl that is cut and folded, with a plastic tube (think fish tank filter/pump tubing) glued together with the black rubbery CA glue. I have found functionally identical vinyl sheet on McMaster/Carr's website.

    david f likes this post


      Current date/time is Tue Jul 23, 2024 4:36 pm