Re: Micro rudder
- Two hands on a little boat reaching??? Down wind nearly as bad? Going to windward with a genoa jib usually produces the most weather helm on modern boats. Why so much weather helm on such a small boat? I thought the purpose of a cat yawl was to get good balance on all points of sail and not have a heavy helm.
--- In email@example.com, "William" <kingw@...> wrote:
> The forces on the rudder and tiller can be considerable when sailing a beam reach and running, which is the strong-suit of these boats. The stock plans call for a wooden rudder stock with a wooden blade. I think that's weak sauce, primarily because the joint where the blade meets the rudder stock is prone to cracking and separating. I have sailed reaches when I had to use both hands on the tiller to keep my Long Micro on course and I was working my arms. The good news is that these boats FLY on these points of sail and it's a blast. But you don't want your rudder blade falling off. Roger Keyes, during his trip to Kangaroo Island, describes having to reinforce his blade-to-rudder-stock attachment by binding with rope or twine.
> I suggest welding a rudder stock and tiller blade from sheet steel (or stainless if you are independently wealthy). I made mine myself from a sheet of steel and a length of automobile exhaust pipe. You can purchase the steel and cut it with a jig-saw. I welded mine too, but you could take the assembly to a shop and have them weld it. Even an automobile exhaust shop could weld it. Then coat the whole assembly in fiberglass and epoxy (I strongly suggest fiberglass, and not just coating with epoxy. The epoxy will chip and once the steel starts to rust, things will get ugly). If you want to see pictures of how I built mine, there's pretty decent detail in my Youtube "building Long Micro video." Look around 2:00 minutes, and 2:37 for the rudder-head detail.
> If you are building the regular cabin Micro, the rigging should be similar to my LM (if you're building a navigator, disregard). I've posted two videos which show how I routed my halyard and snotter lines on my LM. They are Boring (with a capital B) but might give you some ideas.
> Bill, in Texas
> --- In firstname.lastname@example.org, Bruce Hallman <hallman@> wrote:
> > On Sun, Nov 7, 2010 at 12:35 PM, rod_cahill <rod_cahill@> wrote:
> > >
> > >
> > >
> > > Hi,
> > > I am now at the stage of making the rudder and tiller but thought it best to consult the brains trust first. Does anybody have any improvements on the stock standard bolger rudder/tiller assembly that they can share with me? Any problems with the standard setup?
> > > Also, my micro has the mast setup on partners built into the bow like the long micro and the foredeck will be built in with access from inside the cabin. I am wanting to see a picture with the exact placement of all cleats, blocks, etc on the foredeck so I can fit them before closing off the deck. Thankyou.
> > >
> > > Rod Cahill
> > > Bowning (near Canberra)
> > > New South Wales
> > > Australia
> > >
> > You mention 'cabin' not 'cuddy'. Are you building the cabin version,
> > the Navigator Micro?
> > My opinion is that the rudder tiller cannot really be improved from
> > the plans. (There is a bit of a detailing issue of making the hole
> > shroud through the bulkhead tight from outboard engine exhaust).
> > The rigging and sheeting of a Navigator Micro rig depends on the
> > detailing of the cabin windows, and the choices you make for the mast
> > stepping and this gets complicated quick.
- End plates help a low aspect ratio rudder, if it's shoal water you're after, but a high aspect ratio reduces drag the most. The high aspect ratio rudder can be smaller and you will get some reduced helm effort. For more greatly reducing helm effort, the "balanced" aspect of a rudder is more important. You can mix and match - a low aspect rudder can be balanced to get low helm effort. You're arms are happy, but the rudder is draggy and the boat is not moving as it could. - Bill
From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of etap28
Sent: Sunday, November 14, 2010 10:34 AM
Subject: [bolger] Re: Micro rudder
correcting myself... actually, the high aspect rudder doesn't reduce the amount of drag, it just changes the "gear ratio" so to speak of the steering
so it doesn't have much effect on speed but it does lighten the helm drmatically... the longer and skinner the blade, the less leverage the blade has over the relatively longer tiller
--- In email@example.com, "etap28" <dave.irland@...> wrote:
>funny about those traditional catboats... if you make a high-aspect rudder, a typical modern blade, the weather helm is mitigated hugely. Obviously if you have a "barn door" sticking out the back, with about the same lever arm pulling against the tiller as the tiller is pulling back, it's gonna hurt--especially with a low aspect sail sticking out over one rail about 20 feet.
> I'll tell you what's
>Bolger actually used on a lot of his designs, you could totally eliminate the weather helm and hide that force vector in sideways torque against the rudder shaft
> Also, if you wanted to make a clever semi-balanced rudder, of a type
>cat boat types but nobody was all that interested . . . (PS I actually know first hand that it works. I've had a few catboats, including a Woods HOle Spritsail boat, one of about 3 in existence, and I made a nice foil shaped kick up rudder for it and it sailed like a bullet... the absence of massive weather helm obviously gets rid of a lot of drag).
> I used to preach this all the time to the traditionalist