|Subject: [harryproa] Re: Harryproa design page|
|From: "chesapeake410" <email@example.com>|
|Date: 4/13/2008, 3:55 PM|
For autopilot could you use a simple tiler pilot and attach it to a
bell crank or lever (tiller) that had a clamp to lock it to control
line going from rudder to wheel. I expect you could not use the auto
tack function but would have to move it to other rudder or have two
tiller pilots. You would not expect to use this for short distances
do to the hassle of changing it when you shunted but when you expect
to be on the same course for a long time it may be useful.
I like the idear of using rope cable for wheel steering as I beleive
you have used on some of the Harryproas but what do you consider the
pros and con of this system vs the use of rack and pinion gears or
other mechanical systems. I expect the rope system would be least
expensive and if it is reliable and works well why would you use a
more expensive system ?
--- In harryproa@yahoogrou
> I tried non rotating foils a while ago, but as JT said, they do not
> work as well as rotating ones. There are also balance issues at
> speed. The balance is not a simple function of where the shaft is.
> We usually put the shaft at 20% of the chord which gives enough
> balance without the likelihood of the centre of force on the rudder
> getting ahead of the centre of rotation and causing the rudder to
> rotate. This would be disastrous.
> With the two rudders it is pretty easy to get the boat to steer
> for a minute or two. I have not tried for longer. When i was
> with the Outleader kite on Elementarry I regularly locked the helm
> while I sorted out tangled lines. Zero rocker makes for
> tracking properties.
> I will be testing this further on the solo 15m/50' boat which will
> be having an electric autopilot.. If it won't steer satisfactorily
> for 20-30 minutes at a time, I will try a wind vane. If that
> work, I will just dump the sheets while i sleep.
> On Sun, Apr 13, 2008 at 5:03 AM, George Kuck <chesapeake410@
> > If rudder is symmetric there would never be any reason to rotate
> > 180 (and likely less than + or - 45), You would simply switch
> > on rudders when you shunt.. Is this what you envision or will
you expect to
> > rotate rudder 180 when you shunt ? If you do plan on rotating
> > would it make sence to have a 40/60 or other balance ratio on
rudder so it
> > will have a tendency to rotate on its own when you shunt. This
> > prevent ruder being stalled at 90 degrees and possibly risk
> > plate and would add some feel to rudder .
> > One other question I have had that may be related to rudder
design is the
> > ability of the Harryproa to self steer by setting sail and
> > It may require less than optimal settings for top speed but is it
> > to let boat steer itself and on what points of sailing would this
> > This would be a good trait of the boat if it could be done
without the use
> > of autopilots or wind vane, even if only as a backup for other
> > Happy sailing,
> > George Kuck
> > Chestertown, MD
> > Rob Denney <harryproa@.
> > On Sat, Apr 12, 2008 at 10:31 PM, George Kuck <chesapeake410@
> > wrote:
> > > Hello Rob,
> > > With wheel steering as on a 40' Harryproa will it rotate 360
and then have
> > > to go back 370 to go an additional 10 degrees or will it be
> > > rotatable (to 370 or more). ? Will it be balanced so that there
is no load
> > > (50/50)or (40/60), or other ? Can rudders be rotated 90 degrees
to use as
> > > brake when at speed ?
> > >
> > > Happy sailing,
> > > George Kuck
> > > Chestertown, MD
> > >
> > >
> > G'day,
> > Continuously rotating. Pretty much balanced although there are
> > variations in the balance depending on speed, course, foil shape,
> > fairness and smoothness. You can use it as a break, at least until
> > the sheer pin breaks.
> > regards,
> > Rob
> > ____________
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