An idea for a vent valve

[Kazzer]

Saw this interesting set-up over at Model Boat Mayhem site forum.

Oh! Dear! That's actually worse than a 'noddin' donkey' arrangement I purchased in the USA.
On second thoughts, it was at least metallic, not plastic. I loved the spring! And was that JB Weld around the base?
AND I had to sign in to the site to see the photo - That's really troublesome, 'cos I thought I (we) Wizzy and me, were banned. Maybe it's just The Wizard who was banished? Between us, I think we hold a world record for being banned on sub/boat forums. Isn't it great! Ha! Ha! Ha!

[Slats]

Mike - did I miss something? What is a "noddin donkey arrangement"?
Also the "interesting setup" is what exactly? - there is no link?

In any case I would like some feedback on my mods - no point me going down this track if David has been here done that and it is not viable.
J

[Kazzer]

Hmmm! Where did THAT link go? Over to you redboat219!

A 'nodding donkey' is an oil well pump! It nods up 'n down.

[redboat219]

That's strange, even the links I posted at another website disappeared.
Anyway, here it is

[Slats]

Its "interesting" alright.
Can think of far less cumbersome ways to vent a tank.
I get you comment Mike, F a duck!

Ok now can we kindly ask God to comment on my mods?
J

[ADDINGTON]

Purely for reference, see pictured a 12V solenoid-operated vent circa 1996 that if memory serves was designed by Skip Asay with mods by Matt Thor. No servo taking up space in your engine room.

[Slats]

Nothing wrong with a servo occupying space, especially when it double duties the gas blow or snort pump activation. The other thing is IMHO its not a space saver cf to a servo - if
1) it requires an intermediate device between it and the RX
2) it needs its own pwr supply
3) it requires space for a mechanical linkage
4) all of the above
This looks like an EXTERNAL wet setup- which requires some sort of "wire water proofing of connections" of the wires to the RX (internally) so as to give it commands. Waterproofing connections of PWR wires to external SLAs etc are not without problem but IME far easier to accommodate and achieve than wires that run into a RX or device that goes to the RX.
I know you posted it "for reference", but cf with where we are now its a reminder of where the hobby was and thankfully no longer is.
The SD is simple I aim to keep it like that - with the occasional minor tweak (as per my suggestion).

Thanks

J

[redboat219]

Found this on youtube.

http://www.youtube.com/watch?v=IvXXtxJ52w0

As you can see the vent valve is combined with the blow valve. Works just like a gun bolt.
Pull the bolt out and you vent the ballast tank out the side of the tube. Push it back in to close.
Pushing the bolt further in pushes against a shraeder valve blowing gas into the ballast tank.

[He Who Shall Not Be Named]

All,

I'm reading this. Some good stuff, some crap. Keep it coming. Yes, the SubDriver vent valve needs refinement. So far I like Mike's idea (I'm a whore!).

And John: Did what you illustrated initially -- poor design because: 1. the hole in the cylinder is cambered, not a simple plane, won't permit the rubber element to seat easily and 2. the slightest movement between bulkhead and cylinder and the valve leaks.

David,

[Scott T]

Scott T

[He Who Shall Not Be Named]

A bit cumbersome, Scott.

The trick is to place the rubber element and valve seat as the highest element of the ballast tank or you get a trapped bubble in there.

David,

[redboat219]

In the SD the valve goes into the ballast tank. Why not simplify things and remove the rubber flapper valve and use the screw as a mushroom type valve that goes up and out of the ballast tank. A rubber gasket or o ring under the screw head to seal against the top of the ballast tank.

[Slats]

In the SD the valve goes into the ballast tank. Why not simplify things and remove the rubber flapper valve and use the screw as a mushroom type valve that goes up and out of the ballast tank. A rubber gasket or o ring under the screw head to seal against the top of the ballast tank.

That's is exactly what I suggested.
See David's comments for why its problematic.

Best
John

[redboat219]

here an illustration to what I was proposing. Since the valve seat is outside there is no risk for air to get trapped underneath. the curved top of the ballast tank ensure air flows up.

[He Who Shall Not Be Named]

Nope.

The way the linkage works, the valve must close on the up-stroke. Not the down-stroke.

David,