Hi George,
Engineering on my HP will be finished in Jan 09. I am paying for a full design package to
go for bid and immediate build by a commercial fabricator. (Maybe Rob's brother in
panama) I am expecting it to be finished in Fall 09. Then have to move it somewhere.
Looking at marinas and such near Elizabeth City NC in a few weeks. Easy access going
North or South as long as rudder depth works well enough at 1 meter. Lots of shoaling in
this region. Anyone on the chat would be welcome to come visit once we get the boat to
the US coast. Maybe take it up to the Annapolis boat show and sail around, thumbing my
nose at the lagoons, prouts and such. Condo cats.
Steering is a bugger, lots of chain types, even roller chains can be supplied with allowance
for twist like 8 degrees or so in 4 feet.
I just have an aversion to something that lacks a controlled stop. Relying fully on surface
parameters like friction seems a risk to me. Have no idea how that friction would change
from wet to dry, moldy, grime build up, etc. I know bronze should last 10-15 years, and
would feel the slop long before a failure. Could even change the gear positions to areas
less worn as a temp fix for slight steering lag. Just my preference.
Autopilots are a bugger too. No easy way to sense rudder position, as they are continuous
rotation. Fortunately the new raymarine wheel pilots are adaptive controllers and don't
need the rudder sensor. Still may have to recalibrate rudder center before use.
Look forward to seeing you in a year or so. Will need crew help to move it. Want to be the
first with "big" open water Harryproa experience ? We'll see what breaks.
Best Regards,
JT
--- In harryproa@yahoogrou
>
> Hello Tim,
> I do not think keeping the rudders in sync should be a problem since they are on
separate wheels. If one did "creep" you would not know it (unless wheel was marked)
since you are constantly adjusting wheel to steer and keep boat on course and rudders
straight. If you have any significant slippage while using a tiler pilot you would have a
problem and you would have to make adjustments. If Rob designs system to prevent slip
or have negligible slip it should be fine. If you have a continuous rope loop you can have
rope go two or three turns around control drums which should give it plenty of holding
power. You could coat the drums with a synthetic type rubber coating if need be. Its not
rocket science, I think if there are problems its only a matter of working out a solution.
That's part of the fun of building such a unique boat.
>
> I think the use of chain as you suggested may be a good drive system also, but to
have continuous rotation you would have to have a complete loop of chain or rope but you
would not be able to combine the two. You may also have a problem if chain had to pivot
on axles that were not parralel. I do not know how much you can twist chain if at all. It
may depend on how far apart the two sprocket are as to how the chain can be twisted as it
turns.
>
> Happy sailing,
> George Kuck
> Chestertown. MD
>
> PS; JT How soon do you plan on building and where are you located in the "Carolina's"
north or south ? I may come down to see your boat. I expect it will be another year till I
am ready to start, maybe next winter !
>
> Tim Barker <clairebarker5@
> --- In harryproa@yahoogrou
> >With regard to rope especially when you are controlling two rudders
> with the system i would think you would always have some pulluey creep
> so after a while the rudders could get out of sync. However having a
> wheel and using only one rudder at a time this is not such a problem.
>
> However having creep on a remote tiller system would eventually have
> the tiller sticking out at all sorts of odd angles. My suggestion
> there would be a hybrid system using low stretch rope connecting
> short lengths of stainless " bike chain" which is used in industrial
> food manufacture running on stainless sprockets. Light low maint and
> positive no slip actuation.
> > G'day,
> >
> > This is the simplest system for a pilot. Rope is the simplest for the
> > steering, but as JT says, it has problems with stretch , although
> > breakage should be rare with modern ropes. Once the stretch is
> > removed, it should be pretty uneventful. The best way to remove it
> > is to have an adjustable pulley somewhere in the system. I like th
> > ecertainty of the mechanical systems, but not the accuracy or the cost
> > that goes with them.
> >
> > Luis, on the beams, not in them.. There are some pictures of my
> > rough prototype in the files section.
> >
> > regards,
> >
> > Rob
> >
> > On Mon, Apr 14, 2008 at 3:55 AM, chesapeake410 <chesapeake410@
> wrote:
> > >
> > >
> > >
> > >
> > >
> > >
> > > Hello Rob,
> > >
> > > 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 ?
> > >
> > > George Kuck
> > > Chestertown, MD
> > >
> > > --- In harryproa@yahoogrou
> > > wrote:
> > > >
> > > > G'day,
> > > >
> > > > 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
> > > high
> > > > 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
> > > itself
> > > > for a minute or two. I have not tried for longer. When i was
> > > playing
> > > > with the Outleader kite on Elementarry I regularly locked the helm
> > > > while I sorted out tangled lines. Zero rocker makes for
> > > excellent
> > > > tracking properties.
> > > >
> > > > I will be testing this further on the solo 15m/50' boat which will
> > > not
> > > > 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
> > > doesn't
> > > > work, I will just dump the sheets while i sleep.
> > > >
> > > > regards,
> > > >
> > > > Rob
> > > >
> > > > On Sun, Apr 13, 2008 at 5:03 AM, George Kuck <chesapeake410@
> > > wrote:
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > If rudder is symmetric there would never be any reason to rotate
> > > more than
> > > > > 180 (and likely less than + or - 45), You would simply switch
> > > leading edge
> > > > > 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
> > > 180 then
> > > > > 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
> > > would also
> > > > > prevent ruder being stalled at 90 degrees and possibly risk
> > > braking sheer
> > > > > 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
> > > locking rudder.
> > > > > It may require less than optimal settings for top speed but is it
> > > possible
> > > > > to let boat steer itself and on what points of sailing would this
> > > work best.
> > > > > 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
> > > system.
> > > > >
> > > > > Happy sailing,
> > > > > George Kuck
> > > > > Chestertown, MD
> > > > >
> > > > > Rob Denney <harryproa@> wrote:
> > > > >
> > > > >
> > > > > 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
> > > continuously
> > > > > > 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
> > > > >
> > > > >
> > > > >
> > > > > ____________
> > > > > Do You Yahoo!?
> > > > > Tired of spam? Yahoo! Mail has the best spam protection around
> > > > > http://mail.
> > > >
> > >
> > >
> >
>
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