pl_09

[youtube]http://www.youtube.com/watch?v=3UEpkQPsfy8[/youtube]

oztruck

good work. Any details on the workings?

Skip Asay

Interesting, but it looks as though you made the bow planes operational instead of the stern planes. Hint: submarines control much better underwater with the stern planes operational.

Skip Asay

AQUASUB

They do good both ways front or aft,look at the graupner Shark or my Octura ZX ,or the SB-2.0 with the extra large bow plains made a huge diference,the change in angle is much quicker and more preciese in bow plainsonly subs,for optimal control aft and bow is best.

http://s82.photobucket.com/albums/j2...1-20-08051.mp4

Dave

AQUASUB

The yellow Octura ZX has aileron type dive plains that aid in turning and is a Jet Drive sub,can go alot faster than shown!

pl_09

With 2 expert submariners giving what on the surface seems like opposite views, it started me thinking . Skip & Dave have to be both right since they have enough experience in the hobby. Assuming both are right, it must be the different submarines that gave different results.
I think the centre of gravity of the sub is the fulcrum or pivot, which should be the middle of the hobby sub. The downward force of the front diving plane or the upward force of the stern plane will rotate the sub thru this pivot. I think the effective force is therefore the ' moment force ( upward or the downward force X distance from pivot). Skip is right on the Typhoon because the stern moment due to its longer distance from the middle of the sub, is stronger than the front planes. Dave is also right that it does not matter that much on its sub because that Octura sub has both front & stern planes at equal distance from the middle. Anybody think that I am on the right track ?

pl_09

It is up to you to figure it out since I already included its internal photos

Skip Asay

I think it might be time for a little "How a boat is controlled 101".

Has anybody ever noticed that 99.9999% of all boats, surface as well as sub surface, ALL have their rudders in the stern? There's a reason for this and this is something that was learned the first time 2 guys ever rode a log using branches for paddles. ALL BOATS STEER BEST BY MOVING THE STERN TO POINT THE BOW IN WHICHEVER DIRECTION YOU WANT TO GO. This applies to rudders for turning as well as dive planes for depth change. Has anybody noticed how many full size submarines only have stern planes? Or "disappearing" bow planes? Albacore was originally built with bow planes which were removed fairly early in her career and never replaced. Anybody ever wonder why? I'll repeat - ALL BOATS STEER BEST BY MOVING THE STERN TO POINT THE BOW IN WHICHEVER DIRECTION YOU WANT TO GO. The pivot point is actually WAAAYYY ahead of the center of the boat. For all intents and purposes, the pivot point is the BOW ITSELF and NOT the center of gravity or center of the boat. Will oversized bow planes work? Yes, but certainly not as well as appropriately sized stern planes.

For the same reason, bow thrusters WILL NOT WORK when you're trying to make your boat turn better while underway. They'll work just fine IF MOUNTED IN THE STERN. As I said, though - while underway.

Skip Asay

pl_09

Skip has a very good point. The water resistance will tend to shift the pivot forward.

AQUASUB

No you are incorrect ,the Octura ZX has only bow plains and its 4 batteries are spread out in the hull or the weight is spread out ,also in water a sub can have a very forward cg or forward bateries and as long as its counter ballanced with foam the cg can be shifted but only in water can this happen.Once in motion the cg changes again in turns and dives.
The Graupner Shark that I own has only forward plains and manuevers like a dream got to get ya one!
Think of it this way why are torpedoes made with aft only control serfaces?They are that way so that with little or minimal movement on a already constrained machine since it comes out of a tube , that it will hold true to its course,it does not have to make very sharp turns to hit the target,if it did have to make  sharp turns I would thimk that forward plains would be added.

A good case in point would be my SB-2 it came with tiny forward plains that for the size of the sub where vertauly useless,it was not until I made them six times larger that she finaly manuevered incredibly better,just like a fish from a slug to a shark!
Also the added benifit of having operational bow plains is the preciese depth control while at pariscope depth ,vital on Military subs,I have not seen very many without them.

As the sub dives the forward plains move first as seen in many movies prove, they are moved making the sub  attain the correct angle not too much and too little,if they only had aft plains the sub would not be nearly as controlable as trim tanks would have to be used and would take much longer to control the dive angle,in war thats not good!

In my experiances the sub with the most effective forward plains out manuevers by far a sub that has none or ther just too small along with stern plains.

The Typhoon has also very effective aft plains being that there right aft of the Kurt Knozzles that is the best way for aft plains any thrust is imidiatly used to deflect the thrust current and effect a change in attitude however look at those huge forward plains there that way becuse the sub is so huge and wide that aft plains alone are not enough.


Dave

AQUASUB

Skip the large majority of modern Nuke subs today as well as older subs going way back  have bowplains and for very good reason.Naturaly a vessel will have its rudder at the stern but we are not talking about  rudders,they are for a totaly different dimention!

Bow plains where removed from the Albacore probably because in the persuit of more speed and sream lineing it was thaught that it would be better,but the sub suffered imensly with preciese verticle manuvers and that idea was not made a general practice.
The reason bow plains are made to retract is that they can get damaged at port side and at high flank speed retracted to decrease drag and are not necessary at hight speed ,like a torpedoe,only aft plains will due ,once slowed down or a fast change in direction is needed the forward plains are extendid.


Dave

AQUASUB

As Skip mentioned the CG shifts forward , then hence the forward plains make there best effect,if not why even have them.

Dave

AQUASUB

From what I can see in your  mini sub the aft plains are the only plains working ,make the front work and you will have much better diving and running underwater.

Dave

Skip Asay

If the bow planes are so much more effective than stern planes, it would stand to reason that all of the submarine builders would concentrate on having bow planes. Since they don't.....? That should speak volumes all by itself. Since there are NO submarines built without stern planes but quite a few built without bow planes, well, I think it's safe to say that ALL the submarine experts know a little about what they're doing.

Albacore suffered NO problems when the bow planes were removed. They were considered unnecessary, based on experience. And the CG does not shift forward. It's a matter of dynamic stability. What works for the rudder also works for the planes. The reason bow planes are still in use is to help maintain that all important periscope depth when virtually inches matter.

As far as high speed is concerned, bow planes are rigged out when going really fast since a malfunction causing the boat to dive will allow the boat to pass into it's destruction zone too quickly when going at high speed.

Skip Asay

AQUASUB

As far as high speed is concerned, bow planes are rigged out when going really fast since a malfunction causing the boat to dive will allow the boat to pass into it's destruction zone too quickly when going at high speed.

Skip Asay

That statement alone makes my point ,the bow plains are very very important,let me know if a submarine would go to sea without its bow plains operational.

Also why are bow plains used on modern subs toaday yes they do know what they are doing and yes from experiance from NOT doing it.

If the mighty Typhoon had her bow plains stuck in retracted she would be vertualy impossible to control her depth especialy under the ice!

Bow plains to me are as important as a subs rudder to put it simply .

Dave 

pl_09

I think I finally got it. EUREKA !
You both are right as I originally suggested.
It all depends on what you regard as ' better ' !
The forward dive plane when rotates will create resistance. This point of water resistance creates a new pivot. The momentum in turn creates a ' fish-tail ' swing like what happen to sudden stopping of the car without the anti-lock brakes. So the front dive plane WILL produce both plane force & the fish-tail force, making it more efficient on turning. While this is true, the fish-tailling however will delay somewhat the recovery to go straight . On the other hand, the stern plane provides turn without fish-tailling but will recover faster to go straight after the swing.
In conclusion, if you have very small dive planes, you might consider front planes WHICH WILL BE THE BEST, sacrifying a little bit of delay return to straight line but it will start your turn faster without hesitation.
However if your model sub has larger plane, and you rather like tighter control, turn & fast recovery from turns, you might choose a stern plane AS YOUR BEST.

AQUASUB

Not what I would have ,the bow planes are the best no mater what sub you have and stern plains only assist in attitude control.Make your sub with them and a much better sub you will have.

Dave

Skip Asay

Personally, I'll go by what the engineers do. If you only have one set of planes working, they MUST be the stern planes. Period.

A bunch of years ago, while I still owned SubTech, I used to have to constantly prove that a boat with stern planes only would work just fine with an ADC (Automatic Depth Control) and APC (Automatic Pitch Control). This meant that I would run the boat with the ADC controlling the bow planes and the APC controlling the stern planes. I would then pull the boat out of the water, remove the bow planes, and connect the ADC and APC in series controlling just the stern planes. And then proceed to show everybody that there was no difference. NOBODY could ever tell the difference!

Since a boat is controlled from the stern in either left/right or up/down motion, it only stands to reason that the bow planes DON'T have enough control for proper operations. True, you could go really oversize on the bow planes but why bother?

Look at it this way - say you're traveling at 2 feet of depth and you decide you want to come up to 1 foot (periscope depth). With bow planes only, you would have to come up quite a bit more than 1 foot then move the planes to hard dive before leveling off. And, of course, it would take much more time to achieve that depth, unless you go way out of scale as regards size of these control surfaces. With just the stern planes, when the bow has achieved the appropriate depth, you just level it out with the stern planes and bingo, you're there!

As I said, I'll go by what the experts have been doing for over 100 years. I think it's safe to say that they know what they're doing.

Skip Asay

AQUASUB

Yes they do know what there doing by using both forward and aft plains together to give optimal performance ,if only aft used why make forward ones it cost more,just like watercooling there right.

Dave

Skip Asay

Like I said, Since there are NO submarines built without stern planes but quite a few built without bow planes, well, I think it's safe to say that ALL the submarine experts know a little about what they're doing.

Skip Asay

ADDINGTON

These types of discussions are always entertaining, but at some point reality has to rear it's ugly head.
How many types/classes of submarines past and present have retractable bow planes?
How many have retractable stern planes?
How manyfolks think the bow planes are retractable only to protect them from pier/docking damage?
I am no expert, but as far as model submarines go, I have shot underwater video ofprobably 50 different models of all types and no model with bow planes in my library has matched the performance of a properly balanced Albacore or Skipjack.
They run like they are on rails.

coast219

coast219

A boat this small theoretically could dive using RCABS but I don't see any bladders on the video so I think you're using a small water pump with a vented tank.

Have you seen this Japanese modeler's Typhoon. It uses a gas system with a lighter as the gas reservoir
http://babelfish.yahoo.com/translate...s&fr=fptb-msgr

pl_09

In my opinion, at least to me, on top of entertaining , it did trigger my ' inquiring mind' to understand more about the wise choice of bow or stern planes control, since on hobby modelling we are more or less limited to the original plane size designs of the sub.
Excess over-sizing a dive plane ruins the genuine look. Without Dave & Skip, I would never have the chance of understanding the existence of 'possible' fish-tailling effect .

AQUASUB

Read this it might inlighten you.

http://wiki.answers.com/Q/How_do_submarines_work


These types of discussions are always entertaining, but at some point reality has to rear it's ugly head.
How many types/classes of submarines past and present have retractable bow planes?
How many have retractable stern planes?
How many folks think the bow planes are retractable only to protect them from pier/docking damage?
I am no expert, but as far as model submarines go, I have shot underwater video of probably 50 different models of all types and no model with bow planes in my library has matched the performance of a properly balanced Albacore or Skipjack.
They run like they are on rails.


Yes reality needs to be demonstrated all the time and it good.

 http://answers.yahoo.com/question/in...6140809AAtGCqP

How many types/classes of submarines past and present have retractable bow planes?

Alot more than do not.

How many have retractable stern planes?

Obviusly not necessary and irelavent in this dicution,though they have been known to take out a tug!

How many folks think the bow planes are retractable only to protect them from pier/docking damage?


That is the secound perpose of them being retractable not the primary which is to reduce bow noise where the sonor is located,besides haven't  you or anyone ever busted a bow plain on some obsticle,I have so made mine retract by hydralics,nice!Its common sense man.

I am no expert, but as far as model submarines go, I have shot underwater video of probably 50 different models of all types and no model with bow planes in my library has matched the performance of a properly balanced Albacore or Skipjack.
They run like they are on rails.

Notice he says a properly ballnced Albacore or Skipjack,hey a cucomber properly ballanced will do the same nice and level as does a torpedoe,but go very slow and things change just a bit and control is everything and that is the reality of both model and full size subs if not why bother putting them on ,they are the experts not us ,I just on the other hand make it happen on my ladies,the ones I have left!
I hope this was sufficiently entertaining for you all ,to me its just hydrodynamics of subs 101.

BTW why arent more subs like the Albacore in shape,it is a good desighne ,but in hull only.Speed in the military is not everything as capabilities of detection ecetra increase the sub platform must cunform and compromise reached.
Dave