Thinking outside of the box - two receivers

[roedj]

To All,

Here's the deal. I want to totally separate my 'engine room' from the ballast tank for a couple of reasons which you may not agree with and I won't enumerate here but hear me out.

For the moment, let's agree that that's a good idea. I'm thinking of using two receivers, both on the same channel, each with its own battery. One would be in the 'engine room' to control the ESC, rear dive planes, and the rudder. The other would be mounted in a ballast compartment to control the ballast system.

If the 'engine room' ESC came to smash and its BEC failed, the receiver in the ballast compartment could, at least, blow the tanks and hopefully surface the sub.

What would the pros and cons be of such an idea? Don't just tell me I'm crazy - that's a given. I want sound technical reasons.

Dan

[He Who Shall Not Be Named]

No problem. Been done. I've done it, others have too. No liabilities to this, other than the cost of the second receiver.

So, what's the issue here, you afraid to run a conduit tube through the ballast tank?

Oh, got the check. Thanks.

David,

[roedj]

So, what's the issue here, you afraid to run a conduit tube through the ballast tank?
David,

That's part of it. To me, a tube through anything is just two more seals waiting to fail. I'm going to follow Adm. Rickover here and make the rule,"Minimum penetrations of the pressure hull" or in this case, hulls.

That and the fact that the ballast tank is going to be really big and I want to place it some distance away from and down lower than the 'engine room' for best trimming possibilities.

Dan

[He Who Shall Not Be Named]

Fair enough. And, at some point, a servo/device lead can be too long.

David,

[tsenecal]

I have 3 receivers in my alvin's 4 WTCs.

This is not an unusual concept in the giant scale airplanes where both the number of servos (in some cases dozens) and huge lengths (10 to 15 feet) REQUIRE separate receivers.

[Mankster]

Having 2 receiver does mean you double your chances of a Rx failure. Other than the cost their is no problem.

[roedj]

Having 2 receiver does mean you double your chances of a Rx failure. Other than the cost their is no problem.

Statistically, you're correct but operationally it makes no difference. If only one receiver controls the ballast system, the only system I really care about when it comes time to bring the sub back to the surface so I can go fetch it, then the odds are the same as only having one receiver doing it all.

It's more complex - true - it violates the KISS principle - true - but it does open up other possibilities which may, just may, outweigh the risks.

Thanks to all for their responses.

Dan

[Kazzer]

Maybe I'm missing something here, but surely, if you've trimmed the boat as per Snort, in other words, ballast tank full of water, and boat at periscope depth, then who really cares about any other 'failsafe'? If you're dead in the water, the boat will surface to periscope depth.

[He Who Shall Not Be Named]

... unless your failure occurs below the 'critical depth', where box compression has reduced overall displacement below the weight of the boat -- then it's Davy Jones locker time.

David,

[roedj]

Maybe I'm missing something here, but surely, if you've trimmed the boat as per Snort, in other words, ballast tank full of water, and boat at periscope depth, then who really cares about any other 'failsafe'? If you're dead in the water, the boat will surface to periscope depth.

Fair enough, but I intend to "go in harm's way" and enable the boat to be negatively buoyant if I choose. In that case SNORT will not help and am thinking of installing a D&E Propel system as an emergency backup only to be used when all else fails.

A little background may be in order. I find the KISS principle to be very valid and a good rule to follow except I also find it to be terribly boring. I've built 3 subs now all with the KISS principle in mind and have never had a problem. I've used a DM Propel system, Skip Asay's "T" valve/water pump system and a small piston system. All worked just fine - no problem - BORING!

This next sub will be, for me at least, something new, and I'm not counting the German type IID that I'll continue building when my buddy with the milling machine gets back from vacation around the middle of August, that uses yet another ballast system, i.e., water pump/sealed tank with many years of trouble free use standing behind it - BORING!

I'm thinking of a Main Ballast Tank with holes in the bottom open to the sea, with a small piston in the middle of it for adjusting buoyancy - pos/neg - and a gas system to be used as an emergency backup. A SNORT will empty the MBT when on the surface. I'll probably use DM's twin motor, single screw system to drive this beast. I figure that with a couple a thousand dollars riding on this if my pulse rate doesn't shoot up when I first dive it into uncharted waters, I've wasted my time.

Two receivers, hydraulic or pneumatic system for periscopes, etc., approx. scale 1:30, moderately heavy so it doesn't bob around like a cork. I haven't decided on the skin yet so I don't know what it'll be. I may even throw in a microprocessor or two just for sh*ts and giggles. We'll see.

Dan

[He Who Shall Not Be Named]

Make it a big-scale X-1 (The American one)!

David

[roedj]

It's an ugly little spud, isn't it? Modeling the tail section alone would keep me up nights.

Although at 1:10 scale it would be just a tad under 5 feet long.

Still, where would/could one get reasonable drawings?

Dan

[He Who Shall Not Be Named]

Mewhhhaaaahh! (evil laugh)

Me! That's who!

Send address. I'll forward the entire file. I lofted drawings off the thing when it was doing time outside the Naval Communications Station gate (back when the earth was still warm).

Not a one-off, make tooling -- I want one.

David,

[roedj]

David,

I can't tell you how honored I am to have you ask me this but the sad truth is - is that I'm totally unqualified to even attempt it. I've built plank on frame surface craft and 3 (so far) subs from kits. In any case I'm much more interested in the sub control systems than the individual hull.

Yet, I want to learn how to do the very thing you're asking, not to go into business but just to add it to my arsenal of builder skills so that I can create subs of my own choosing instead of relying on someone else to make a kit.

So, ball in your court, I'm very willing to learn if you're willing to teach realizing all the while that you're a very busy guy and doing this correspondence school style may not be practical at all.

But if it could be done, in the end, who knows, you may create a whole group of model builders with an online tutorial.

Dan

[He Who Shall Not Be Named]

No sweat, Dan. In time you'll learn. All you need is drive. And you've demonstrated that you have it. Start your education by going to the downloads section here. Then visit this site: http://vabiz.com/d&e/articles.html

You'll get some insights into scratch-building there that should be useful to you.

The world is currently full of big-mouth CNC worshipers and those who have big plans to employ 3D printers to produce model kits for the r/c submarine market. So far, not much in the way of product out there derived by these machines for the r/c submarine enthusiast. Apparently pushing a mouse around is just too hard for the pocket-protector crowd; too much like work I suppose.

So, if we want product, its in the hands of the real Model Builder's out there to produce the goods. As it always has been, and always will be. There will never be a viable alternative to good, sound, well executed Craftsmanship, Dan. Welcome aboard.

David,