Florin {VACATIONER} Posted July 1, 2003 Posted July 1, 2003 So I've been working on rigging up the wheel and rudder and the steering components for the past couple of days. I surely didn't think it would take this long to get this done. Anyway, I can only seem to get the rudder box to swing 35 deg to port and 40 deg to strbrd. Is this normal? I have no idea what the turning radius should be. I've triple-checked the plans to see if I've done something wrong, but other than the fact that they're a bit on the vague side, I couldn't come up with anything. The hinges seem to bind against the rudder post and rudder box when they get around the 35 deg. mark. Any help would be appreciated. Thanks Quote
Andrew Posted July 1, 2003 Posted July 1, 2003 Florin I believe that once the rudder passes about 30 degrees it 'stalls' and becomes ineffective, so having the rudder go no further than that could actually be helpful! Hope that gives you some hope :wink: Quote
TexasPhil Posted July 1, 2003 Posted July 1, 2003 I'm curious.. can these rudders actaully cavitate? Or is it just turbulance beyond 30 degrees? Quote
Guest Anonymous Posted July 1, 2003 Posted July 1, 2003 I think if it is cavitating you should be worried about other things. :roll: Quote
Russ Sylvester Posted July 1, 2003 Posted July 1, 2003 When the rudder stalls it is cavitating. The water that normally would curve around to the back of the rudder can no longer curve that far and will create an 'eddy' or cavitation. Thus the rudder is no longer producing 'lift' toward the desired direction. Ray is correct, when this happens it is like someone has thrown out the anchor. 30-35 degs is more than enough swing to accomplish a turn. Quote
Charlie Jones Posted July 1, 2003 Posted July 1, 2003 When the rudder stalls it is ventilating, not cavitating. Cavitation occurs with high speed movement in the water, such as props on very fast boats, where O2 gets literally pulled out of the water, creating bubbles. It is an explosive sort of happening and usually blows chunks out of propellers when it happens. AIN'T gonna happen on a Weekender rudder. Ventilation is when some surface piercing thing sucks air down from the surface, which causes loss of water flow. The little plate above the prop on an outboard motor is there to prevent that and is properly called an anti ventilation plate. And 30 to 35 degrees is all the rudder movement you ever want, so you are fine. Many boats have rudder stops built into them to limit the angle to 30 degrees. Quote
Craig Posted July 1, 2003 Posted July 1, 2003 Yup! All the above and they don't work worth spit after 30 either... Quote
Florin {VACATIONER} Posted July 1, 2003 Author Posted July 1, 2003 The rope is not installed yet (actually I will be using a/c cable, but that's besides the point). I never got to hooking up the cable because I wanted to sort out this problem first (if it is indeed a problem). Where I can see it hanging up is at the straps. It's kinda hard to describe and I don't think the picture would be good enough for you to see (you kinda have to be there) but I'll try to describe it better. It all started with making the straps. I don't see any description in the plans for the radius of the curve of the straps... they describe to bend it 180deg, and that's it.... so I used the thickness of the rudder box and keel post as the diameter of the bend. They are 2 1/4" thick, so the radius is 1 1/8". I then followed the instructions, installed the straps and made the fillers (this would anly apply to Vacationers, because on the Weekender they use eyebolts). Then the plans call for drilling a 1/2" hole in the fillers, on the centerline with the center of the hole 1/2" in... in from what? this is where it didn't make any sense to me... so the first set of fillers I made, the holes were too close to the rudder post/rudder box and culdn't even put in the 1/2" ready rod... the holes wouldn't line up. So I made a second set of fillers and drilled the holes very close to the outside of the circles (only have about 1/4" of "meat"/wood left between the rod and the strap)... this was better, I managed to get the rod in, but now like I said, the rudder box can only turn about 35 deg on either side. The only way I can see this work is by modifying the straps, i.e. elongating the curve, to make it like 1/2 of an ellipse to get the two pieces "away from eachother, because the way it is now it acts as a cam and the more it turns the more the strap/curve gets closer to the opposing member. If you guys figure it's ok like this, I'll leave it and worry about it if it becomes a problem turning later on when we launch. Thanks Quote
TexasPhil Posted July 2, 2003 Posted July 2, 2003 Craig, Well put! Charlie, Thanks for the info. Ventilation huh... OK I guess I will be limiting my tiller, somehow. No point in going beyond 35degrees. Florin, Wow... sorry, I can't follow that. Can you put up a picture? Quote
Florin {VACATIONER} Posted July 2, 2003 Author Posted July 2, 2003 I'll take some pics when I have the rudder box put together again. I just took it off yesterday for I'm getting it ready for the fiberglass phase. thanks! Quote
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