Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: U-33 on June 07, 2014, 02:49:30 pm
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If you're using a WTC with internal or external rods, instead of using brass nuts to pull things up tight, use the end section of old couplings. They are much easier to grip with wet (or in my case, arthritic) fingers...I've just changed the ones on my Akula WTC.
(that's NOT the Sheerline WTC in the pic, in case someone was ready to comment on it....)
Rich
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Or if you've got the space, wing nuts are a cheap and easy tool free system.
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I can't get on with wing nuts for some reason, damn things always go on cross threaded for me.
Rich
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Rich...I am sure it must be an optical illusion :o, but the clear WTC [the tube itself] appear not to engage over the captive o-ring in the endcap?.......Derek
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It's not supposed to, DW...the end cap compresses the O ring against the edge of the tube. There is a proper technical term for it, but I can never remember it. It works...that's the main thing.
Rich
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That's known as axial seal compression.
That's done a lot because of the poor internal tolerance of most extruded plastic tubing. Also some builders are concerned about stressing the acrylic by compressing an o-ring internally.
I think the tolerance issue is less of a problem for smaller diameters e.g. <90mm. With regards to stress, I don't know, but I've seen a few acrylic WTC's with radial sealing, and they seem work just fine.
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There you go, DW...I knew there was a proper term for it. Thanks Andy...
Rich
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By couplings, I take it you mean the universal joint couplings - Richard? (Like knurled but even more so.)
It is the core of the Sheerline design, so you wouldn't want to change it anyway, but I think that the design with all those threaded rods is rather old-hat and overkill. German modellers have been rather scathing - what with their bayonet couplings and all!
For anyone building their own WTC, radial O ring seals are the way to go , in my opinion. If you can't find a suitable piece of pipe then look for another one! Even PVC sewer pipe works well. (Not see- through of course, but fine if your sub is not mainly for display.
David