Rudder rigging

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Re: Rudder rigging

Postby GreenLake » Thu Sep 15, 2016 9:29 pm

I'm saying that if the rudder swings back, you'll definitely feel additional force in otherwise same conditions.

Not saying that a change in conditions couldn't change the rudder forces as well.

If you sail with a non-swinging rudder, the force you need to apply at the tiller should relate to the force that the rudder needs to supply to counteract the forces caused by the sail and the hull.

If you are sailing the boat flat (not or not excessively heeled) there shouldn't be a net steering contribution from the hull, but if you are heeled very far, the immersed hull becomes rather asymmetric and will definitely steer your boat in a curve all by itself (can be used in light winds to help the boat tack).

Sheeting in the main or freeing the jib results in the boat wanting to turn upwind (causes "weather helm"). When the wind gets stronger, the apparent wind moves back. (Contribution from boatspeed becomes less). If sail trim stays the same, that could increase the tendency to round up (more weather helm). However, once the boat speeds up, the apparent wind would move forward.

Hard to separate the contributions from the sail; if you want to be sure, you'd better test this a bit. With a motor at your disposal, you can push your boat to and past hull speed while it's level (and no contribution from sails). If the uphaul gets slack by a bit that would tell you that the rudder moved.

I would definitely fix the hydrodynamics of the forward attachment; there's no question that you are paying a constant penalty there.
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Re: Rudder rigging

Postby SUNBIRD » Mon Dec 12, 2016 12:35 pm

Lines to raise the Rudder were never standard on the Day Sailers from O'DAY. The late 1983-85 DS II and all DS III did have a line to hold the rudder blade down. The rigging of that down line was similar to the rudder on the O'DAY 19, 192, and 222. The picture below isn't best, but from what I can tell looking at a 222 rudder and this one, the down line attaches to the leading edge of the rudder blade in the notch where the rounded top meets the blade, it then leads up inside the pintles (I think there are metal spacers between the side plates that the line runs over?) to the underside of the underside of the tiller where there was a clamcleat.
rudder.jpeg (21.13 KiB) Viewed 9356 times
DS III Rudder in place.jpeg
DS III Rudder in place.jpeg (26.83 KiB) Viewed 9356 times
Last edited by SUNBIRD on Fri Dec 30, 2016 11:40 am, edited 1 time in total.
Rod Johnson, "SUNBIRD"
1979 DS II, # 10201
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Re: Rudder rigging

Postby GreenLake » Mon Dec 12, 2016 5:47 pm

I would say that this is probably generally true (not just for the DS) that downhaul lines are fitted with higher priority or probability....
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Re: Rudder rigging

Postby kokko » Mon Dec 26, 2016 3:54 pm

i rigged uphaul and downhaul lines on my ds rudder much like in the pics. however I use a clam cleat so it will give in case of grounding. The pics show a horn cleat
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Re: Rudder rigging

Postby jeadstx » Tue Dec 27, 2016 4:00 am

On my rudder downhaul line I use this auto release clam cleat from Duckworks. ... /index.htm

1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
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