Ballast

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25 October 2015 at 13:46 #4265
BRYAN ASTON
Participant
@bryanaston57723
Magnetic keel
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25 October 2015 at 13:46 #61022
BRYAN ASTON
Participant
@bryanaston57723
greetings all'

I have just completed building the SY MEDEA overall weight is as the instructions

On its maiden voyage this morning it ran perfectly in a straight line ,turning however was heart stopping experience, how it remained upright was.mystery, to me ,I believe the correct description is tender, are there any experts out there that have a plan for a removable keel, magnetic or mechanical, all suggestions would be very welcome

The lake was dead calm

Bryan
25 October 2015 at 16:06 #61023
Martin Field 1
Participant
@martinfield1
Bryan, a chap on a different forum sent me details of his way of attaching a fin keel to one of his large square riggers.

It involves the addition of a length of aluminium angle under the boat, to which the external, weighted keel is attached with machine screws. When on display, the external keel can be removed and the ally angle barely visible from usual angles.

I hope that helps.

Cheers,

Martin
25 October 2015 at 16:17 #61024
Colin Bishop
Moderator
@colinbishop34627
Hi Bryan,

Somehow there is too much weight too high up in the model. My modified Medea is also the correct weight but is very stable and only a bit vulnerable to a stiff gust of wind which can push it over as far as the deck edge but it bounces back immediately.

My batteries are cylindrical NmiH right in the bottom of the hull and the speed controller and R/X are also mounted low down alhough the motor is hung from the underside of the deck.

Colin
25 October 2015 at 17:05 #61027
BRYAN ASTON
Participant
@bryanaston57723
Colin

The 7.2v battery is on the bottom of the hull all electronic equipment is on the bottom ,the motor is halfway down the hull,nothing extra is in the superstructure . Lead shot is used as the ballast , it was tested in the bath and bounced back up when I held it right over until the decks were nearly awash, perhaps ,bearing in mind my previous experience with the Calypso when it capsized perhaps I am a bit apprehensive ,I will get some more lead shot.

Martin

If all else fails I may try the removable keel

Thanks
25 October 2015 at 17:41 #61028
Colin Bishop
Moderator
@colinbishop34627
You can ballast it down to just below the indicated waterline as this won't be noticeable when the model is sailing due to wave action and transparency of the water. Given the way the hull swells out from below this should give a useful amount of extra stability. Try an extra 5mm deeper, it could make quite a bit of difference.

Colin
25 October 2015 at 19:04 #61033
Andy Stoneman
Participant
@andystoneman15177
Hi Brian, The keel on my model is a long length of steel, its the barge yacht which was shown in the Model boats special edition. I found that a strong magnet allowed me to fix and move about when I wanted to a ballasted torpedo shaped weight attached to the fin, I did wonder if the magnet was strong enough and found it was more than capable of hanging on even with the odd bump on the bottom. I found that I had at first fixed my Ballasted torpedo weight too far aft which caused the model to stall when turning, so a quick adjustment sliding the ballast below the mast stopped the stall. Providing you have a strong enough magnet it should work fine.

Andy
26 October 2015 at 08:52 #61043
BRYAN ASTON
Participant
@bryanaston57723
Colin

I will buy more lead shot today

Andy

I will search eBay for a strong magnet, to all watch this space.

Bryan
26 October 2015 at 08:56 #61044
BRYAN ASTON
Participant
@bryanaston57723
Ps

There is a MEDEA on Model Boat Mayhem with sails, so there is hope.

Bryan
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