Rudder extensions for Graupner Southampton

[meechingman]

Hi all.

After another outing grimacing at Southampton's poor turning circle and zero steering going astern, I decided to act! Another club member at Eastbourne said 'double the rudder size', so I did.

Simple extensions were made from plastic card and simply slipped over the existing rudders and, for ease of fitment, taped in place with electrical insulating tape. Off to the lake again and, oh my, what a result.

The turning circle has nearly halved, even at low speed and, albeit using full rudder, I can steer very sharply port or starboard [at will!!] when going astern. I flattened two sets of batteries practising manouevers but got the hang of it in the end. The only thing I can't do is go astern in a straight line. [Any ideas on that, BTW, as the screws are counter-rotating.] A couple of members said that it now looks like I have a 'secret weapon' for the steering contests, which was very kind, but I still have a lot of practising to do!

Anyway, now I have to make a permanent job of things, and have drawn up a basic diagram. The idea is to make the extensions slip over the existing rudders again [taking the hull apart to install completely new rudders would be a pain, as this is an RTR model and wasn't meant to come apart that easiliy], but obviously they'll be glued on this time.

Any comments or suggestions on the design, dimensions etc of the extensions, or what best to make them from, would be very welcome. Thanks.

Andy G

[Shaun Hendricks]

How much 'play' is in your rudders? This wouldn't show up in forward maneuvers, but straight line reverse, the rudders might flutter or even hit play 'stops' that would make the boat do funny things.

I'd concentrate on taking out ANY slop in the rudders. I wonder if actually giving them some slight 'toe-in' toward each other would help. This would keep them pressing against each other under power/movement and hopefully taking out any slop in their operation. It would slightly decrease the speed of the boat. I wouldn't suggest any more than 1-2°, but you'd have to experiment with it. This is done on RC (and real) cars but I don't know if the same principal would work for boats with dual rudders. Any boat experts out there know if this would work or not? :confused:

[meechingman]

Just checked! The quick answer is almost zero play on the rudders, and the link to the steering servo feels very solid too. the existing rudders are very, very slightly 'toe in'. I don't know if that's by design or just the way this model is.

Andy

[Ghost 2501]

the toe in is to give the outer rudder more deflection, if anything, they need to toe out so when deflected, the inner rudder has more swing tham the outer rudder

Even my southampton has a 40ft turning circle, meech, try re-wiring her to allow for individual motor comtrol

[meechingman]

That's next on my list, Ghost. There's plenty of room for 2 ESC's, the compartment's already there for it. Hopefully not a deck-removing job!

My Southie never had a 40' turning circle, but it's around 10' now. Going astern, about 6' once she starts to swing. Has to be done slowly, though.

Andy

[charge1(ds)]

Make sure your radio endpoints are set 100+% also if the backing proplem arose when you added your fins they may be disaligned with eachother and not striaght.

[Ghost 2501]

meech, its easier than you think to get the deck off, I have had the deck off my southampton after the starboard engine decoupled itsellf from the shaft.

1/ remove superstructure to reveal battery lid

2/ unscrew bollards and remove antenna base.

3/ remove the rear mooring bollards, (they conceal 2 screws)

this if i recall allows all screws to be revealed. unscrew them and the entire deck comes off. theis has to be done to reveal the equipment tray, however im not sure on how to disassemble that as yet. but some bits will have to come off it first. southampton comes apart easier than you think

[Ghost 2501]

Hi all.

The only thing I can't do is go astern in a straight line. [Any ideas on that, BTW, as the screws are counter-rotating.]

i think that it is because the motors are wired in series, so there is minor rpm differences

[LtDoc]

Increasing the size of the rudders definitely helps steering, forward. Adding 'flanking' rudders in front of the props will definitely help steering in reverse, and you won't believe what the boat will do in forward motion with them. (A servo and a few rudders are cheaper than another ESC, and I'm cheap! :) )
- 'Doc