Subject: Re: [harryproa] Windmill drive
From: "Rob Denney" <>
Date: 4/10/2006, 9:37 AM

Excellent idea, ask them to send me a cheque (sign it, don't bother filling in the amount) and I will get started :-) 
Carbon would reduce the weight, but the heaviest item was the steel 4:1 reduction gears, which would be difficult to build in carbon.  The boat (9m Iroquois cat) could be much lighter, and also much better optimised, as could the rig (3 bladed, 9.6m dia windmill), and particularly the prop (1m dia, 4 bladed variable pitch, which became controllable pitch after an unfortunate incident with the control wire).  The best we did was 6 knots into 20 knots of breeze.  The theory said that we should be doing 13! 
I would not bother lowering it in a gale.  We left the blades feathered and tied in F8 with no problems. 
----- Original Message -----
From: colcampey
Sent: Monday, April 10, 2006 5:37 PM
Subject: [harryproa] Windmill drive

Someone on the electric boat group proposed the novel idea of
eliminating the electric motor between the wind generator and the
Do you think it's time to revisit your idea, now that you can use
carbon to keep the whole thing light and demountable (for gales). A
light carbon boat will also need a smaller windmill than your
original - or two even smaller windmills.
Use the windmill whatever the wind direction whenever there's enough
breeze and the kite downwind in light air.


Col C

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