HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 08, 2013, 03:13 PM
Registered User
Joined Jan 2010
57 Posts
Discussion
Current progress on my ballast tank and questions

Right here's the current progress towards my basic model submarine ballast tank (apologies for large dark and dingy photos).
I've got the rough idea ready and have started producing the endcaps though I want some advice before I carry on to the next stage.






First of all Iím a little worried about the seal size.

As you can see above the wall of the pipe is kinda thin (about 3 mm), the pipe can take the pressure but it gives very little surface area for the rubber between the lexan cap and the pipe to hold an airtight seal.

Iím going to try the method drawn below but would appreciate advice on whether Iím about to spend a lot of time on something that wonít work.





I do intend to cut the pipe down into sections of 30cm (30 at the front and 30 at the back for radio gear, servos, motors etc and 30cm in the middle for the tank).

The pipe is 4 inch wide (roughly 10cm diameter) so this aught to give me very roughly a 3 litre tank although the pressurized air will take up some space but none the less it aught to be enough to bring the sub under the water.


Sooo thoughts sugestion, point and laugh
over to y'all
twiglet123 is offline Find More Posts by twiglet123
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 09, 2013, 08:17 PM
Registered User
Bloomington, IL
Joined Apr 2004
74 Posts
Here is a suggestion: can you find nesting tubes one size larger and smaller?

If so, you could cut short lengths, say 1 cm or so, and glue those to the ends. That will result in a 9 mm wall thickness. Which may be more than enough to give you a good seal.
eRaptor is offline Find More Posts by eRaptor
Reply With Quote
Old Jun 10, 2013, 09:07 AM
Registered User
Joined Mar 2005
63 Posts
Why is there a continued preference for cylindrical pressure compartments which require complete removal for internal adjustments and push-pull control rods instead of rotational through-hull shafts? Sure rectangular tanks are not that hard to fabricate and in-boat adjustments are now simple. A removable lid for major adjustments and small hatches for switches and charge plugs.
Farm Flyer is offline Find More Posts by Farm Flyer
Reply With Quote
Old Jun 10, 2013, 01:42 PM
Man from Atlantis
Sub culture's Avatar
London
Joined Nov 2003
905 Posts
You can put rotary control seals on a cylinder too. Cylindrical enclosures are much better at resisting water pressure, and are easier to make watertight. How many full size subs do you see with anything other than a cylindrical or spherical pressure hull. the only one I recall is the Brandtaucher, and that sank!
Sub culture is offline Find More Posts by Sub culture
Reply With Quote
Old Jun 12, 2013, 08:30 AM
Registered User
Bloomington, IL
Joined Apr 2004
74 Posts
Though in all fairness, a compound pressure compartment also works: I have used part of the hull for one wall, and then put in semi-circular ends and a flat top. Of course, this is not removable, but is it is easy on space requirements.
eRaptor is offline Find More Posts by eRaptor
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Ballast tank questions twiglet123 Submarines 5 Jun 05, 2013 10:03 AM
Discussion Simple ballast tank ideas? twiglet123 Submarines 7 May 24, 2013 05:47 PM
Question Newbie - Short flight times on my current setup? EPP Angel Jakeo Electric Plane Talk 4 Mar 26, 2013 01:47 PM
Question Is it possible to build a sub with out a pump and ballast tanks?? addictedtoplanes Submarines 7 Feb 07, 2013 11:00 PM
Question Water pump for sealed ballast tank; Bogdan.Manole Submarines 6 Jan 30, 2013 11:37 AM