An idea for a vent valve

[redboat219]

Found this slide type vent valve used on a Japanese conversion of a Revell 1/72 scale Type VII u-boat.
Looks like a scaled up version of the the guillotine style slide valve David designed for the micro SD.
But instead of using a solid plate to close off the vent hole it uses a perforated plate which is aligned by a servo.
There was some concerns about air leaking pass the slide plate but once the set up was immersed in water the water became sort of a gasket sealing the air in.

So it's possible then to use it on a bigger boat.


Vent close


Vent Open

[oztruck]

It might have trouble getting ALL the air out, because of the flat surface. Unless it is dead level air can be trapped all over the place. Which might make it hard to trim.

[Slats]

Yeah well that's one way to open a vent, but that sub must weigh in at a slip disc or two, looks like he dry hulled it euro style.

Guys just took deliver of two new Subdrivers, being putting them together, if you can't get the valve to open and close using David's setup you really not trying hard enough. (I put myself in that category too, a little effort and all is OK).
Best
J

[oztruck]

At last I got around to doing a video on the twin pump snort system. It is only a video of the sub sitting in the test tank but it will give you an idea on how fast and controllable it is.

http://www.youtube.com/watch?v=caKGgTQNKts

[He Who Shall Not Be Named]

John and Redboat,

Great minds think alike, John. Back in the mid-80's I indeed formed the vent valve seat and rubber element pretty much as you illustrated. Here are the flaws with that design:

The cylinder is a simple curve, with a radius not indicated in your 2D illustration. A conical, hemispherical or flat rubber element will not apply sealing pressure to the forward and after ends of the hole owing to the downward slop of the cylinder at the left and right hand sides of the vent hole. To achieve an equal sealing pressure on the rubber under this hole, the rubber element has to be cast or cut to conform to the inside radius of the cylinder -- that proved to be labor intensive.

The second big problem of the simple hole-in-cylinder arrangement was that a shift of the ballast bulkhead (off of which the ballast linkage arm was attached through its pivot pin) -- should the bulkhead move so much as a cunt-hair -- the rubber element would fall out of alignment with the vent hole and the unit would leak.

All that you illustrated has been explored through practical experiment, and more, over the years. The best version is the one you now see employed aboard my line of SD's.

Hey! ... I'll change the design of my vent valve the moment you plant a big, heart-felt, sloppy kiss on the lips of the current President of Task Force 72. How bout that!

And that carburetor part: too expensive, too complicated, and won't get all the air out of the ballast tank, Redboat! The only things I want standing proud on the cylinder are the *** manifolds.

YOU PEOPLE!!!!! I write you articles, I buy you books, I send you to school! What do you do?! ... that's right ... you eat the ****ing Teacher!

David,

[Rpmtech1]

Swamp cooler fill valves work good as vents and are easy to actuate, if your into that type of home brew WTC stuff... sigh


Obviously you cut the float off and leave a stub on the valve for the servo to move.

[Slats]

.......

The best version is the one you now see employed aboard my line of SD's.
........
Hey! ... I'll change the design of my vent valve the moment you plant a big, heart-felt, sloppy kiss on the lips of the current President of Task Force 72. How bout that!
.........

David,

Thankfully I am dialed in with the vent as is....

......

Guys just took deliver of two new Subdrivers, being putting them together, if you can't get the valve to open and close using David's setup you really not trying hard enough. (I put myself in that category too, a little effort and all is OK).
Best
J

The horror the horror, I need a mecuricome shower just thinking about it. Be off my food for at least a week. When does this vomiting sensation leave- *******!:wink:

[He Who Shall Not Be Named]

Thankfully I am dialed in with the vent as is....


The horror the horror, I need a mecuricome shower just thinking about it. Be off my food for at least a week. When does this vomiting sensation leave- *******!:wink:

Excellent. Mission accomplished! My work here is done.

David,