1/72 HMAS Rankin (Collins Class)

[junglelord]

We must remember that control surfaces of exotic modern planes and modern submarines are interfaced with powerful computers and they do not just fly by the seat of their pants. Is that not true? They have gryos and software and servos. Hence we do too....is that not correct?

Or do modern subs have full manual control with no interface from a correction software and electronic hardware?
I realize that most devices full scale and rc scale can fly by the seat of their pants but sounds like its more difficult then fun sometimes. That is surprising to me as I have no experince yet, except with a Walmart sub, which was extremely stable. I look forward to trying the Seawolf. Mr Merriman says, I have no need for function dive planes on the bow of that boat. So many ideas I had were ALL WRONG....LOL

[Slats]

Rick,
David I think is not saying this at all.

The boat is more manourvable and is more twitchy. Hence less stable and more in need of a sub leveller.

I think David Batagol's boat is simply setup in such a way that by some sheer stroke of luck he finds he does not need it - but the science on this says otherwise.

John

[toppack]

Yes, they found out a long time ago that 4 fins of equal size was very stable and easy to control, in air, so looks like it would be in water also.
Example: German V-2 Rocket
It's when they are not equal size, shape and area that you get into trouble.

[Slats]

Be my guest...to add a copy to that thread -glad we all learnt something.

J

[junglelord]

The claim, even suggestion, that X-tail boats are more dynamically stable than cruciform configured boats is total bull-****. Not in my experience. X-tailed submarines -- because of the accumulated force of all four, not just two, control surfaces working a specific axis -- are, if anything, more difficult to keep in a straight line than submarines with cruciform configured appendages.

It takes a very skilled Driver to operate a submerged model submarine without the aid of an artificial stabilizing device working the stern planes. I've driven both types; with, and without an APC in the stern plane loop. An X-tail boat is very maneuverable -- it is also very 'touchy'.

I would like to transfer this information to my other thread on various designs and submarine performance.

Nice set of pictures of various designs. I think the Seaview would be the odd man out being a science fiction design with only half a X tail design due to the Cadillac fins, the Manta fins pushing down and that wedge head, certainly like no Military design. Of course having a RC Seaview has been a childhood dream of mine. 30 years in the making. I cannot wait to fullfill that dream. I remember wondering as a boy, that they should make a full scale Seaview. I figured it must be the best design...being young and all, impressionable as a boy in the late 60's, that this wonderful design must be the killer sub design of all designs. Of course that is not true at all and in fact the head makes it an ineffecent design, with such a huge bow wake and the cadillac fins are not good for fast turns. Oh well some dreams are just fancyfull ideas of a young boy carried over into adult hood. Enter Dave Merriman and the Seaview that handels extremely well. Large turning radius, but seems to take a straight line without nose diving. Nothing like the Skipjack model, which could run circles around the Seaview....


That is an interesting point of observation about the need for a ADF . I have not taken my Robbe SeaWolf V2 out yet. Its Maiden voyage will be this spring. I will have an ADF by then and I can put it in either the SeaView or the SeaWolf.

[Slats]

Thanks David, a leveler will be fitted.

J

[He Who Shall Not Be Named]

David M.. is there science behind the X fin and stability that would mean a leveler is superfluous ?

J

The claim, even suggestion, that X-tail boats are more dynamically stable than cruciform configured boats is total bull-****. Not in my experience. X-tailed submarines -- because of the accumulated force of all four, not just two, control surfaces working a specific axis -- are, if anything, more difficult to keep in a straight line than submarines with cruciform configured appendages.

It takes a very skilled Driver to operate a submerged model submarine without the aid of an artificial stabilizing device working the stern planes. I've driven both types; with, and without an APC in the stern plane loop. An X-tail boat is very maneuverable -- it is also very 'touchy'.

[Slats]

David M.. is there science behind the X fin and stability that would mean a leveler is superfluous ?

J

[redboat219]

Of interest with David's Collins is that its one of the most stable steady and manourvable boats I have seen, and yet he drives it with no electronic leveller!

I have never seen a RC sub (other than this one) without a leveller not porpoise (even slightly), but it does beg the question about whether there is something special about X fin setups, or maybe its just the luck of his setup that he does not need one?

J

I remember reading something on RCgroups about operating X-tail boats without APC. They owners claim they don't need them. It maybe that their boats are so well balanced that they can overcome the dynamic forces of water moving over the hull during submerged running.

[Slats]

The only other RC Collins I know of in a scale close to 1/72, has been built by Dr David Batagol and Jim Russell here in Australia. Those boats are not quite 1/72 - but they are very very close.

Of interest with David's Collins is that its one of the most stable steady and manourvable boats I have seen, and yet he drives it with no electronic leveller!

I have never seen a RC sub (other than this one) without a leveller not porpoise (even slightly), but it does beg the question about whether there is something special about X fin setups, or maybe its just the luck of his setup that he does not need one?

J

[Slats]

Well if a kit does eventuate I'd buy one anyway in addition to getting the one I am working on working. I love these subs.

I am very proud of my country's submarines that we decided to build from scratch. We have faced many problems and trials and enormous cost over runs, but IMO we now have the finest diesel subs ever made. Sure we don't have speed and range of a nuke, but these units do a great job. They are the largest conventionally powered submarines in the world and now extremely quiet. It just a shame we are so short on manning. Submariners down here can earn big bucks - thought about enlisting last year as an old fart, but the deployments are a young mans game. The wife would kill me.

The thing I love about these subs is there are not just coastal and shallow water platforms (which most conventional boats are used for), the Collins is a long patrol blue water platform too, and works well when put up against its bigger modern nuke brothers.

J

[He Who Shall Not Be Named]

David,
sorry to say this is going to be a one boat deal only. Allan has told me for now he is uncertain about how he might progress this at a later date with a perhaps new kit, and as such he is happy for me to have as per my original plan just a boat for myself right now.

If he does a kit in the future - a boat will be coming your way.

Best
John

No problem at all. And extend to Allen my sincerest good wishes with the project.

(Damn!)

David,

[Slats]

David,
sorry to say this is going to be a one boat deal only. Allan has told me for now he is uncertain about how he might progress this at a later date with a perhaps new kit, and as such he is happy for me to have as per my original plan just a boat for myself right now.

If he does a kit in the future - a boat will be coming your way.

Best
John

[Slats]

I look forward to that and I am really pumped about my own possiblities to become a master modelers apprentice. I have more confidence that this hobby is all about problem solving and learning how to accomplish new skills as you grow. A hobby that contiunes to keep you sharp and aware and inventive.

I want a few machine stations, drill press, lathe, would be nice and a good clamp....the right tool for the right job...thanks for pumping me up.
I'll drink to THAT!

That my friend is one of the reasons I try to keep tabs on what David's doing.
I don't want to sound like a Merriman suck hole, but I know no other master builder as generous with his time and passing on his successes and some experience of failures too with others. After 15 years I am still learning and enjoying the hobby. No reason why that can't continue. Good for you being pumped up. I for one am positive that anyone can achieve their goals if you want it badly enough. And as my dear old mum told me from an earlier age....never ever give up on something that you want or is worthwhile and never ever let anyone stop you from learning.

best
John

[He Who Shall Not Be Named]

John,

Absolutely!! .... secure Allen's permission first. You (unlike so many in this game) understand and respect the proprietary aspects of a producers work. And so do I. It's up to Allen.

You'll take something in return (if we secure permission) for a COLLINS kit (no matter how basic -- two hull halves and a sail would be fine with me) AND LIKE IT!

******!

Hell yes, A proper 'how to' of master and tool making, coupled with production of the upper hull piece, would be a welcome and vital piece of knowledge for everyone here, myself included.

You did good!

David,