Yes I agree with your comments as when we fitted the CE2 engine into Lexa (many years ago) the engine /gearbox moved the prop shaft back a small amount and when I first used her the rudder vibration was very noticeable.I seem to remember a distance calculation I was told about at the time between prop and rudder and rear bearing of prop shaft (I'll have a dig around in my paperwork ,unless Julian remembers who I think told me about it in the first place?) My solution was boat out the water and a new shorter propshaft was fitted ,which sorted the problem. Hope that helps All the Best Bernard NB Lexa
_____ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Michael Askin Sent: 02 June 2008 22:20 To: [email protected] Subject: Re: [canals-list] Rudder Judder On Mon, Jun 2, 2008 at 7:09 PM, Callum M0MCX <[EMAIL PROTECTED] <mailto:callum%40mccormick.uk.com> uk.com> wrote: > New boat, new prop with slight-to-moderate rudder judder from tick-over > upwards. > > How can I cure this? Ask builder to change prop? Could be anything, but there is a small chance that the prop is just to close to the rudder. Changing the prop may help (larger number of blades, greater area... Crowther Engineering in Manchester may be able to furnish you with a suitable prop). Rudder balance could also be the problem, extending (or even reducing if too long) the balance on the rudder (the bit infront of the tiller) might help. Kismet's prop is set to high up with in the hull and we get cavitation, and vibration because of it. Our tiller, especially on high speed runs does judder. The rudder on Shoestring also shuddlers a little, and more when there is something on the blade. Not sure if any of that helps, but some dimensions of your underwater bits may help a little to diagnose the problem - any pictures? Cheers, Mike -- Michael Askin http://shoestring_ <http://shoestring_DOT_zapto_DOT_org/> DOT_zapto_DOT_org/ [Non-text portions of this message have been removed]
