Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: Patrick Henry on March 13, 2012, 02:54:20 pm

Title: Operational front 'planes?
Post by: Patrick Henry on March 13, 2012, 02:54:20 pm
The pic shows the position and size of the forward 'planes on the CONFORM boat. Honest opinions now, chaps...is it worth me making them operational?

I'm contemplating having the forward ones operational and the rear ones working from an auto leveller, but I'm not sure...how say you guys?


Rich

Title: Re: Operational front 'planes?
Post by: Subculture on March 13, 2012, 03:59:12 pm
It will behave rather differently to a boat with solely stern plane control. I think some boats really benefit from having both sets of planes working, whilst others don't really need it.

If the rear planes are totally automatic, you may need to consider increasing the area of the front planes to enable good control of depth, or including manual control of the rear planes too.
Title: Re: Operational front 'planes?
Post by: thegrimreaper on March 13, 2012, 04:01:14 pm
Rich I have the Akula and the vanguard both with operational front vanes Akula has a leveler fitted and works fantasticaly Vanguard was harder on its maiden voyage but leveler is ordered and on its way when I had the U47 that didn't have opo`s on the front and was a pig I was over controlling all the time and couldn't get her to run level
where as, me being a beginner I find it dead easy to get under with the front planes working and also to stay pretty much at a nice depth.

Regards Mark
Title: Re: Operational front 'planes?
Post by: Patrick Henry on March 13, 2012, 04:44:08 pm
Mark...Andy...that'll do for me. many thanks for that information, I'll be installing the front planes tomorrow (hopefully) if all goes well.

Thanks fellas,



Rich
Title: Re: Operational front 'planes?
Post by: bobk on March 13, 2012, 05:00:40 pm
Fascinating gents, thanks.  Having two subs on the stocks I am learning all I can.
Title: Re: Operational front 'planes?
Post by: Subculture on March 13, 2012, 07:20:35 pm
In general, the best people to consult about a boats handling are those who run the same type of boat. This concept boat is really a very clean version of a simplified hull of revolution, so should handle very similar to those boats, but lack any sail induced roll. I read somewhere that the Permit class was originally intended to be sans sail, but they found it too much of a compromise and settled on a much smaller sail than the preceding Skipjack class.

Unusual subjects like a K-class are a bit more tricky- not many people have built those, bu there are one or two knocking about out there, albeit at larger scales.

Another thing to check is information on the fullsize boats handling. Chances are, a model will share some of that boats vices.

One thing we can't scale down are water molecules, and unfortunately that can sometimes pose a problem with control surfaces, especially as the scale of model gets smaller. To get the kind of response the builder is hoping for, it is sometimes (but not always) necessary to sacrifice a little scale fidelity and increase the size of the control surfaces.


 
Title: Re: Operational front 'planes?
Post by: merriman on March 13, 2012, 07:23:55 pm
It's been my experience that if the model is over thirty-inches in length and has, as an intrinsic aspect of the prototype design, either bow or fairwater planes, to make both sets of hydroplanes practical. Almost always (Disney NAUTILUS and SEAVIEW being exceptions) make the two sets of hydroplanes to work independently -- don't link them up electronically or mechanically.

The stern planes always driven by an angle-keeper (with driver over-ride in the loop for trimming and 'emergency deep' maneuvers). The bow/fairwater planes driven directly by the driver for depth control. If employed, a depth-keeping device will be placed in the control loop between bow/fairwater plane servo and driver input. The pressure sensing element of the ADC must be positioned as far ahead of the boats CG as possible!

Use the stern planes to change/maintain pitch angle (a course form of depth control where hull lift is generated by changing the angle-of-attack of the hull to the fluid it moves in). Use the bow/fairwater planes for fine depth control.

David
Title: Re: Operational front 'planes?
Post by: bobk on March 13, 2012, 07:49:21 pm
Unusual subjects like a K-class are a bit more tricky- not many people have built those, bu there are one or two knocking about out there, albeit at larger scales.

Another thing to check is information on the fullsize boats handling. Chances are, a model will share some of that boats vices.
 

I am fully expecting the "turning circle of a battle cruiser" and probably replicating the most challenging dive characteristics of any real submarine.  Dive planes and rudder are scale. 

PS:  Full marks to Caswell for shipping my Kli-Con magnetic couplers so fast.  Great service.  I have since ordered their tiny Lipo guard unit.
Title: Re: Operational front 'planes?
Post by: Subculture on March 13, 2012, 08:19:56 pm
I doubt the turning circle will be much worse than a modern SSBN, possibly better if you employ differential throttle control for the twin screws, although that may not make a huge difference. Beam to length ratio is almost 13:1 on this boat, a modern day Vanguard class is about 12:1, and although the latter has more rudder area, it also has a fixed shroud around the prop which acts like a fixed rudder and hinders the turning radius.

But, you have that nice little 212 when you require something that turns on a sixpence! Can't beat x-tails for agility.