Rudder Alignment

[chris piazza]

Quick question on rudder alignment. I tried to adjust the rudders this past weekend and the only adjustment I could find is the bar that goes between the two rudder arms. I could not get enough adjustment out of this bar, more like for fine tuning, not for a greater movement which I need. Is there another way to adjust them? The rudder post appears to have a keyway with no adjustment or maybe I am missing something.

Chris
Superior Nights 53C

 

[rwetherington]

What are you trying to adjust with the rudder bar? as far as rudders go you set them straight then toe them in 3/4 of an inch.

 

[REBrueckner]

Can't tell what you are trying to accomplish, but there are generally three aspects to rudder position and movement: the toe as mentioned above, the length of the hydraulic cylinder arm and position of the hydraulic cylinder itself, the position mechanical stops....if I recall my Hatt has blocks which stop further outward turn.
Absent any of these solving your problem, you can always add a modest size trailing piece of bronze plate to the back edge of your rudders for increased control...but that will make your steering more sensitive at higher speeds.

 

[chris piazza]

Maybe I didn't explain it well enough, I need to adjust the rudders 3"+, the only adjustment I can fine is the bar the goes between the rudder arms. This bar has reverse threads on one side so as you turn it it tightens or loosens both rudders. Is there an adjustment other than this bar? Is there an adjustment in the rudder post, by the key way?

Chris
Superior Nights 53C

 

[rwetherington]

Chris,

I am missing something. You need to move the rudder arm by three inches? Are the rudder arms setting forward and aft now or are they off by three inches?

 

[chris piazza]

Ok I found an old picture that Mike posted to help me better explain. Is there an adjustment on the rudder post? In the picture if I loosen the two bolts (yellow and green arrows) will the arm move on the post? or will the key way NOT allow this. I need to get more adjustment to get them aligned than the bar allows. A tech I talked to on the phone today stated the only way to make further adjustment is to add 2-3" to the bar. I don't think he knows what he taking about, I am sure the bar didn't shrink three inches and thats what put them out of alignment.

Chris
Superior Nights 53C

 

[Sonny]

There are only two adjustments one is the tie bar that connects the two rudders together and as you found, it acts like a turnbuckle. The other adjustment is on the end of the hyraulic ram shaft. You gotta figure out how your steering became 3" out of alignment. Usually this stuff is set once, torqued down and that's it, they don't "wander" at all. The tie bar sets the rudders parallel or toe-in, the adjustment on the end of the ram synchs the rudder position with the ram position ie rudders midship, ram centred.
Have the rudders been hit and not repaired or hit and not repaired properly?

 

[chris piazza]

To the best of my knowledge it has never been hit, at least I know for sure during the time that I have owned her. I may be embellishing a bit on the three inches, maybe closer to two. While standing behind the boat in-line with shafts for reference I noticed that the port rudder was straight in line with the shaft, however the starboard rudder was turned out maybe 1-2". The tie bar is not long enough to make the adjustment. I guess I could measure what I need to make it correct and put a extension on the tie bar?

Chris
Superior Nights 53C

 

[REBrueckner]

The steering arm is locked in place via the shaft key to the rudder post...it is not adjustable.

Two alternatives: (1) Make believe you never saw the "misalignment"..if you are not getting any vibration, who cares...

(2) If you try to adjust the stbd ruddder in, via rotating the tie bar turn buckle arrangement, you'll end up with the port rudder too far in ... you'll need to adjust one rudder steering arm to a different position on the tie bar by removing the steering arm from the rudder post...then turning it a few turns on the tie rod before reinstalling on the rudder post.

 

[Sonny]

>>>the starboard rudder was turned out maybe 1-2"

You gotta make sure the wheel is centred, then check the rudder alignment. Do this by locking the wheel to one side, measure the hydraulic ram, lock the steering opposite then measure again. Have someone turn the wheel until you see half of what you measured on the ram sticking out. You could just count the turns from lock to lock on the wheel but it isn't as accurate as measuring. Once the ram is centred, check your rudders. You may find that each one is off centre by 3/4" and well within the adjustment of the tie bar.

 

[Trojan]

Where are you measuring ? The front leading edge of the rudder or the trailing edge. Both rudders must be centered before measuring. Measure the front leading edge. It makes a big difference. It's very hard to believe there off that much. As said previously, once set from Hatteras they don't move unless damaged.

BILL

 

[J's Dream]

While standing behind the boat in-line with shafts for reference I noticed that the port rudder was straight in line with the shaft, however the starboard rudder was turned out maybe 1-2".

Chris,

Leave it alone. Straighten the wheel out, and then BOTH rudders will be off center by between .5 and 1 inch, the way they SHOULD be. They can't be centered, they must be either toe in, or toe out, just like they are.

Jason

 

[Avenger]

The rudder arms on my 36C have offset keyways. I did a lot of math at the time I was working with them, and I think the offset was 7 deg. So if you flip the arm over the rudder ended up indexed 14 deg. from its original position.

If you have them both facing the same direction it will have the effect of offsetting them both to one side.

Have the arms been off recently? I found mine set up with both keys out and almost 5 inches of toe-in. When I flipped them over, keys in, I ended up with about 1/2 inch of toe-out.

In your situation I would disconnect the ram, run it to full travel in one direction, measure it and then run it all the way in the other direction, measure it and divide by two. Set it to that dimension so it's centered and then look at your rudders and key indexing.

Hope this helps.

 

[chris piazza]

When I am standing in line with the port shaft and turn the wheel until the port rudder is sq with the shaft the starboard rudder is toe out approx 2" (this is the aft part of the rudder) So I guess if I turn the wheel to move the port rudder out one inch that will give me an inch on each side? and this is good enough? Also I don't know if the arms have ever been off.

 

[Sonny]

You got it! As already mentioned, get your hydraulic ram in the centre position then check your rudders. If you haven't messed with the adjustments I'm 99% sure you'll find them to be equally toe-out.

 

[Maynard Rupp]

Chris...I can't beleive that your rudders are that far off. Something is wrong here. Look at the tiller arms on both rudders and make sure they have keys and that those keys are lining the slots in the shafts and arms up. I would have you visually center the rudders as best you can and measure the distances front and rear between the rudders. I would do that at the widest spot on the rudders. Try to make sure your tape is level and move it up and down to obtain the lowest reading. Do this on the rear edge and the front edge. They should have up to 3/4 " of toe in. This means that the measured distance on the front, (leading edge), should be 3/4" LESS than what you measure on the trailing edge. Don't try to use your eyeball, use the tape. I will bet that it is very close as it sits.

 

[saltshaker]

I've heard some say you should be toe in and others say toe out. Is there a preference and if so why?

 

[Avenger]

When I am standing in line with the port shaft and turn the wheel until the port rudder is sq with the shaft the starboard rudder is toe out approx 2" (this is the aft part of the rudder) So I guess if I turn the wheel to move the port rudder out one inch that will give me an inch on each side? and this is good enough? Also I don't know if the arms have ever been off.

I was asking if the arms were off recently thinking somebody may have pulled one of them to fix something else, and unknowingly flipped it over which would change the offset. It could have happened before you bought the boat.

I looked at Sam's parts inventory and they show several rudder arms. Some have offset keys, others do not. You'll have to inspect yours to see what you have. Fixing your problem may be as simple as pulling an arm off and turning it over.

2 in. of toe is too much. Any more than necessary to prevent "flutter" is just adding drag. When I finally decide it's "spring" enough to de-winterize and do some tests I will report on the performance difference of my nearly 5 in. of toe vs. 1/2 in. It looks like it's fairly significant, but I need to isolate the "rudders as speedbrakes" part of the equation. Stay tuned.

 

[chris piazza]

Thanks to all, I blew off tommorrow at work and am going to run up to the boat and try the suggestions provided. Hopefully its something simple that I missed, I will post a response when I return.

Chris
Superior Nights 53C

 

[Trojan]

You must measure the leading edge only. The trailing edge will very depending on the rudder shaft offset. Toe out can result in quick steering. Toe in is the best way. Toe in will keep the rudders evenly preloaded better than toe out. The trailing edge distance will always be greater than the leading edge because of the design of the rudder offset. Don't even try to align the rudders by looking forward from the stern. Your eyes are deceiving. The shaft is never in the center of the rudder for and aft. To center the rudders. Use a straight edge along each side of the keel and draw a line back to the rudders. measure the distance between the 2 lines and create a center line. Measure from the rudder shaft center to the line. Then use the same line and measure the leading edge of the rudder to the center line. Adjust the rudders both side to side adding and subtracting until the leading edges are equal both sides to the center line. Then measure the distance between the leading edges and compare the rudder shaft center distance for your toe in amount. No matter how you measure it, You will only be close and that's good enough.


BILL