G'day,
No viewable drawings yet, and the pictures of the setup on my boat
don't show much. Seperation is pretty easy as there is plenty of
room above and below the beam.
Main issue has turned out to be the bearings. My pvc drainpipes with
only 150mm/6" of seperation between top and bottom bearing jam when
reaching at over 12 knots. Most disconcerting! I am currently
fitting bigger ones (still pvc drainpipe, with the option of using
balls for comparsion), but UMPWE, balls or roller bearings will be
the go on the bigger boats.
regards,
Rob
On Jan 16, 2008 12:31 PM, David Howie <dana-tenacity@
>
>
>
>
>
>
>
>
>
> Don't Apologise mark, I love what you guys are doing.
>
>
>
> Any drawings /pictures? I'm curious how you are going to get enough
> separation top to bottom to support them.
>
> ------ Original Message ------
> Received: Tue, 15 Jan 2008 03:20:17 AM MST
> From: Mark Stephens <mark@harryproa.
> To: harryproa@yahoogrou
> Subject: Re: [harryproa] Re: Anyone there ?
>
>
>
>
>
> The biggest negative about the hull hung rudders, well the mk 2 version, is
> they would be difficult to replace once the shear pins broke. At the moment
> they are designed to 'break away' in the event of a collision. You would
> then have to retrieve them from the end of the attachment line and refit
> them with new shear pins. This may seem like a big disadvantage but it will
> only happen in a catastrophic event which would render any catamaran with a
> stuck and broken daggerboard at best and a split hull and bent rudder shaft
> at worst.
>
> We are not in the business of selling boats using boatshows and brochures.
> We are enthusiasts trying to promote the proa as a viable alternative to
> people who understand that Harryproas don't have the decades of development
> other multis have. Some things, rudders in particular, will go through many
> iterations before the perfect solution is reached and we keep all of our
> developments transparent. Maybe not commercially sensible but that's not
> what we are about. I'm sure all those subscribed to this group are here
> because of this.
>
> Hopefully the beam mounted rudders will prove to be the best option. Rob
> has experimented with them and they seem to be working well. The biggest
> concern was the distance from the boats centre but this has proven OK on
> Elementarry. Blind Date will be trying them as will Solitarry. As they will
> kick up in both directions and won't be as draggy let's hope they prove
> successful.
>
> Mark
>
> Rob Denney wrote:
>
>
>
> G'day,
>
> The side of hull mounted rudders work well, as did the in hull dagger
> rudders before them and the in hull spade rudders before them. They
> are far better than the rudders and daggerboards in most multihulls.
> However, none were the perfect solution and this is what we are
> looking for. The beam mounted rudders are another (quite large) step
> in this direction and have been tested by me on my Elementarry, and
> now on my solo boat. They will then be included in the plans.
> Anyone who is now at the rudder stage of their build should discuss
> the options before they proceed.
>
> Because I believe it is in everyone's interest if I am upfront about
> what we are doing and give details of experiments that have been tried
> (rail mounted riudders etc) there is a lot of discussion. These are
> ideas, not "designs" and they may or may not end up on the plans.
>
> Rudders and daggerboards/
> boats. We are trying to reduce the potential for damage, reduce the
> cost and improve the performance rather than taking the stance of the
> rest of the industry that there is nothing that can be done about it
> and that it is normal for daggerboards to break and hulls to split
> when they collide with something and that boats should be confined to
> deep water because of the depth of their rudders.
>
> The side of hull rudders in dagger cases do hit a fair bit of water
> as can be seen in the Rare Bird video. They may or may not be
> draggier than the conventional slot for daggerboards. They are not
> likely to cause any handling problems and the spray they kick up is
> not likely to reach the cockpit. They do have the advantage that in a
> collision, they kick up and in storms, shallow water and on the
> mooring, they can be lifted. Their biggest advantage is that in the
> event of damage, there are no holes below the waterline.
>
> The beam mounted rudders keep all these advantages and solve the spray
> problem. They are also considerably easier to build.
>
> regards,
>
> Rob
>
> On Jan 15, 2008 1:54 PM, Jim Baltaxe <jim.baltaxe@
> >
> >
> >
> >
> >
> >
> >
> > Hi Robert
> >
> > If what you say about the rudders is true then why is there, or has there
> > been, so much worrying about the design of the rudders? Rob and others
> have
> > been concerned about the lower brackets being caught by waves, designs
> have
> > been posted for rudders hung from the akas and there was even a proposal
> to
> > hang rudders from stub akas. I'm not even talking about hanging a single
> > rudder/daggerboard from a track on the lee hull and hauling it end to end
> > during a shunt.
> >
> > I am aware that there are other things than simple strength or turning
> > moment involved in rudder design but it seems to be received knowledge
> that
> > rudders are the "Achilles heel" of proas.
> >
> >
> >
> > Enjoy
> >
> > Jim Baltaxe
> >
> > They said, get a life. I looked on TradeMe but I couldn't find one.
> > ____________
> > From: harryproa@yahoogrou
> On
> > Behalf Of Robert
> > Sent: Monday, 14 January 2008 4:01 p.m.
> >
> > To: harryproa@yahoogrou
> > Subject: [harryproa] Re: Anyone there ?
> >
> >
> >
> >
> >
> > -Hi Jim,
> > I was certainly impressed with the build when I saw 'Aroha' in the
> > earlier stages- I even helped with a bit of the fairing on one of the
> > rudders so it must be good! I cant see any problems with the rudders
> > as far as slowing the boat down and Rare Bird was a good pilot study
> > for the robustness. The brackets are strong enough to take the sailing
> > loads so the bit of slapping won't worry them. There is not much
> > increase in wetted area if the brackets hit a wave and it would damp
> > even further the minimal chance of hobby horsing, which could actually
> > improve performance. (I reckon they also provides a means of getting
> > on board again from in the water)
> > Coming over bars is a good test for robustness maneuverability and
> > handling.
> > Wish you well in the legal wrangles,and I am sure that Bain would be
> > happy for Aroha to go to a good home,
> > Robert--
> >
> >
> > In harryproa@yahoogrou
> > >
> > > Hi Robert
> > >
> > > I did get out onto him/her on the last day before Bain so kindly took
> me
> > > to the airport, but unfortunately it was pelting down like mad. We
> rowed
> > > out to the boat, moored in a river near Bain's house and had a good
> look
> > > around but never got off the mooring. We had neither the time nor the
> > > breeze to prove much.
> > >
> > > The boat appears to be very well built and very much what I do want.
> > > Enough room for one or two people for extended coastal cruising and the
> > > pop-up canopy over the upper cockpit was a cozy place for us to shelter
> > > in the rain and talk about, as well as look at, the boat.
> > >
> > > My only real reservation about the design is the ongoing question of
> > > rudder attachments. Aroha's appear solid but the lower brackets
> > > certainly will certainly be caught in almost anything more than a flat
> > > sea. I really don't know whether that would make much difference to
> > > overall performance, though.
> > >
> > > I did see Aroha come across the bar into the river a couple of days
> > > earlier and it was an impressive sight.
> > >
> > > I am still working on the legal and financial issues so I am hoping
> that
> > > I will be able to make a reasonable offer fairly soon. In the meantime,
> > > I do wish Bain good luck and if I miss out, so be it. If everything
> > > works well, perhaps I'll be able to get across for another look and a
> > > ride later this year.
> > >
> > > Enjoy
> > >
> > > Jim Baltaxe
> > >
> > > They said, get a life. I looked on TradeMe but I couldn't find one.
> > >
> > > ____________
> > >
> > > From: harryproa@yahoogrou
> [mailto:harryproa@yahoogrou
> >
> > > On Behalf Of Robert
> > > Sent: Thursday, 3 January 2008 11:58 p.m.
> > > To: harryproa@yahoogrou
> >
> > > Subject: [harryproa] Re: Anyone there ?
> > >
> > >
> > >
> > > -G'day Jim,
> > > Sorry to hear of your difficulties. Not a nice situation but there can
> > > be an afterlife
> > > Did you get a chance to sail on Aroha?
> > > Robert
> > >
> > > -- In harryproa@yahoogrou
> >
> > > <mailto:harryproa%
> > > <jim.baltaxe@
> > > >
> > > > Hi Robert &al
> > > >
> > > > I'm in exactly the same position which is why I've had my head down
> > > for
> > > > a while, since Derek's workshop and my visit with Bain. I'm still
> > > trying
> > > > to work out the "disengagement" (what else do you call a "divorce"
> > > from
> > > > a legally recognised, long-term, relationship?
> > > > get the money together. Sorry Bain but I am trying, really hard.
> > > >
> > > >
> > > > Enjoy
> > > > Jim Baltaxe
> > > > 209 Derwent Street
> > > > Island Bay, Wellington
> > > > NEW ZEALAND
> > > > +64 (04) 938 6018
> > > > 027 563 5018
> > > > They said, get a life. I looked on TradeMe but I couldn't find one.
> > > >
> > > > ____________
> > > >
> > > > From: harryproa@yahoogrou
> >
> > > <mailto:harryproa%
> > > [mailto:harryproa@yahoogrou
> >
> > > <mailto:harryproa%
> > > > On Behalf Of Robert
> > > > Sent: Thursday, 20 December 2007 4:16 p.m.
> > > > To: harryproa@yahoogrou
> >
> > > <mailto:harryproa%
> > > > Subject: [harryproa] Re: Anyone there ?
> > > >
> > > >
> > > >
> > > > -waiting with bated breath for the next development of the Harry.
> Love
> > > > to see the promised photos of Sidecar and Solitarry I am still keen
> to
> > > > get a Harry but health and wealth defy me. The concept still makes
> the
> > > > most sense to me and the boats out there look pretty good. If I had
> > > > the cash I'd probably just buy Bain's Aroha and get sailing.
> > > > Meanwhile I'm investigating doing a KSS system using polyprop and
> > > > epoxy with an end bulkhead with foam ends.
> > > > Robert
> > > >
> > > > -- In harryproa@yahoogrou
> >
> > > <mailto:harryproa%
> > > > <mailto:harryproa%
> > > > wrote:
> > > > >
> > > > > Nobody more in this group ?????
> > > > >
> > > >
> > >
> >
> >
> ____________
>
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.516 / Virus Database: 269.19.2/1224 - Release Date: 14/01/2008
> 5:39 PM
>
>
>
>
>
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