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Rudder Hum ...The 1st Mod...

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Anonymous (not verified)
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Rudder Hum ...The 1st Mod...

Hi All,
One of the first things we noticed about Animal was an annoying Vibration around the 5Kn. mark. This was very quickly narrowed down to the rudders.They felt "sloppy" so we got to work. 1st the long vertical rudder pins were removed and replaced with S/S bolts with nyloc nuts X4.This prevented the rudder stocks moving up and down and by careful adjustment a lot of play was removed,, on to the tiller there is a discrepency in the size of the vertical bolt on which the S/S tiller mount swivels and the size of the holes in the bracket attached to the transom, The Transom ones being to large, extra nylon washers were added and an additional lock nut, the bold was again carefully adjusted and then "double locked",
All this improved the feel but the Hum was still present,all be it at about 6 kn now. Following some on water testing, It transpired that the "poor" fit of the blades in the stock allows them to vibrate through the water, Small wedges of timber were placed into the gaps and "Hey Presto" a quiet tight boat...... An Inspection of a 27.7 that lives near us reveled adjustable nylon wedges fitted as standard and they also keep the blade from damaging itself on the narrow aluminium frame of the stock by spreading the load. The owner has not had any Vibration issues,
On inspection it looks like these blocks can be easily fitted to the 260 rudders ,thus doing away with the need to "chock" every time we sail... Regards Iain

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