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Thanks for the picture.... was trying to invision how a washer would solve the problem... I guess a gigantic one would...

Bob

cptron wrote:

fishheadbarandgrill wrote:Thanks... Seahorse... any more shims laying around you'd like to get rid of?

Seahouse, Mine look just like fishheads. I would appreciate being able to take an extra set off your hands for the price everyone is giving here. You have given the best information on straightening out these things yet that I can find.

Sent you an email.

fishheadbarandgrill wrote:thanks Seahouse. I'll give it a shot... I know you gave me the spacing between the rudders and the blades...

But can someone, who's aren't bent to hull, measure the inner distance betweent the blades?

Thanks,
Bob

One thing I like about these boats is that the parts are built fairly consistently to even fractions of an inch. So if you measure the thickness of the top part of your rudder (I'm going to guess it's 1 1/4") and add 1/8" to it (guess, = 1 3/8") it should give you your target dimension between the tangs.

What we really need are the big steel washers. I wonder where we can find those things?

BOAT wrote:What we really need are the big steel washers. I wonder where we can find those things?

The big washers don't take up any of the 1/8" gap between the tang and the rudders, so the slop will remain. The big washers are a band-aid to the real problem, which is the slop between the rudder and the tangs.

Well, you can tighten them up to close the gap (a bit), but the tangs will no longer be parallel because the steering tube is solid where welded and prevents it from closing in. A spacer will still be needed to take up that space.

Having said that, I have made up a set of 3/16" thick X 2 1/4" stainless steel washers (somewhat smaller than pictured because I used material on hand) for this purpose, but haven't installed them because I needed longer pivot bolts to accommodate the extra thickness. I never bothered* because they haven't been needed after 3+ seasons, and it would cloud the issue of determining the value of the plastic spacers alone.

-B.

*It has nothing to do with the fact that I'm lazy.

I did not say to eliminate the spacers, I still think the spacers are absoulutly needed or the rudders will not go up and down. We don't need a source for the spacers - we have you for that - what we DO need is a source for the washers.

I think the washers are a good idea but they will need to be very thick to make a difference. The plastic spacer will not prevent the tangs from bending because the bolt hole in the rudder itself is large enough to allow the rudder to swing a little from left to right. The factory did that so the bolt would not crack the rudder at the bolt hole.

The tangs are not strong enough to hold the rudder from flexing to the left and the right, so they bend. The bolt hole on the rudder is not strong enough to hold the rudder from flexing left to right either.

The only way to stop the rudder flex/wobble is to apply pressure on the rudders at these specific pressure points in red right here:

Once rudder slop is fixed

I found rudder alignment is also an issue.
Here's what I did to create a precision alignment system for my 26X
All I did was weld two tabs to the steering bar and add a big turnbuckle (see link below)
I was finally able to get the rudders aligned perfectly and they stayed that way
https://app.box.com/s/hs8n1mxkzvjwczjid8z7

Also, with this adjustment, I could adjust the rudder alignment, while actually sailing (better than doing it static). Takes two people (one to keep the boat on course and be lookout).

The steering bar has enough flex to allow for a good range of alignment with this mod. It also has enough flex to get the rudders out of alignment, very easily, without this improvement. I got very tired of trying to align my rudders at home, only to look down at them, whiling sailing, to see one pointing straight and the other one slightly turned (enough to actually see). You know this has to cause a lot of drag. And it also means only one rudder is actually working. The one that is not running straight is just causing drag.

I can only speak for the 26X steering here. Later boats may not have this problem.

Best Breezes,
Steve K

All good points BOAT and Steve. All my comments pertain to the M , and some maybe to other models too.

Rudder alignment is easy to check on the hard. Prop both rudders so they are parallel to each other and the ground (the up / down haul lines do this nicely), then measure (a tape measure is good enough) the centre to centre points at the tip, and then at the base (where the pivot is) of the rudders.

The two measurements should be pretty close to being the same, allowing for equal play in both directions. Note that small differences in this measurement (over the length of the rudder) will translate to much smaller differences over the width of the rudders, so don't be alarmed and chase after differences unless they are large.

Brian, your advice assumes that the rudder post line-up of the top pintles and the lower attachment tangs are in agreement with each other. In practice I've found the drilling points and possibly welds are sometimes off. Otherwise even if the rudders are not in parallel alignment with each other when vertical, they can still be adjusted by your method. I think the measurement must be made by creating a line rearward from the sides of the down-turned blades (taking into account curvature) and then adjusting that according to your system.
R.

I cannot believe tattoo hasn't fixed this issue once and for all, by using a thicker gauge, and posted a link where we can all buy retrofits for our boats...
Ix

Maybe their testing of such resulted in broken rudders?

Crikey wrote:Brian, your advice assumes that the rudder post line-up of the top pintles and the lower attachment tangs are in agreement with each other. In practice I've found the drilling points and possibly welds are sometimes off. Otherwise even if the rudders are not in parallel alignment with each other when vertical, they can still be adjusted by your method. I think the measurement must be made by creating a line rearward from the sides of the down-turned blades (taking into account curvature) and then adjusting that according to your system.
R.

Yeah, in effect this does create a line that extends rearward from where the sides of the down-turned blades should be assuming the blades are straight. This checks the alignment so that the two blades are parallel both to each other and to the water flow when steering straight ahead and when in the full-down position, to ensure that there is no excessive parasitic drag from it. If they are out (mine were right-on when new from the factory, and still were this spring, after 3 seasons, when I checked them again), an adjustment can be made inside the boat to the length of the rod that joins the bell cranks at the top of the rudder pivot tube.

The motor alignment with the rudders should then be checked if you make an adjustment to this. I found that this was out somewhat on my boat, but it was not a factory responsibility either. As I recall, it was easy to adjust that.

Note that I have fitted bushings and seals in place at the top of the rudder pivot tubes that have removed play in this area. See the “mods” section.

Now, if the rudder pivot tubes are not parallel to each other at the start (port to starboard tilt), then the rudders will be canted inward or outward when fully down, but will still be parallel to the water flow when facing straight ahead, and shouldn't be creating any excessive drag. When turned to steer the boat though, if the tubes are out of parallel, then the rudders won't be either.

I'm curious, how much (in degrees) would you say yours were out? The only way I can see to correct this is to open up the (4) clearance holes on the lower brackets on the transom, move them into alignment, and retighten them.

If the rudder pivot tubes are not parallel to each other (fore to aft tilt) the rudder stop screws can adjust some of this out, and, of course, it would not affect the measurement of the rudders when they are in the horizontal, straight back position I suggest above. In this case shims would need to be placed under one of the lower brackets to bring them parallel, if they were out that far.

You could also check that by taking a spacing measurement with the rudders in the full-up position, and then in the resting-just-above-the-ground-level position (assuming you didn't have a place to deploy them full-down, vs straight back horizontal like you have) and compare them. I would think most of the time the two measurements should be pretty close to each other(?) For fun I might check mine in the fall if I remember.

-B.

The reason the rudders don't work very well is because they are not wide enough. A single rudder on a boat our size should be about 20 inches or more from front to back and not go so deep into the water. That is why the boat is gamey - not enough rudder in the water.

There is no way the rudder system on the boat can handle a rudder that big. You can easily fit much wider rudders by just making them wider:



But, the rudder steering system is not strong enough and would bend and the top of the rudder would crack off if the rudders were the right size.

One big wide rudder in the middle usually works better. As long as the boat is not too heavy the stock rudders are marginal and will work ok. I think the top of the rudder will break off if the rudder tangs are so strong that they never give - a bent tang is better than a broken rudder from a safety point of view. That's probably why there is no "factory solution" to this issue.

Boat, I think the issue of breakage (as mentioned in the latest MMOR postings) has more to do with excessive sea forces coupled with some degree of rearward positioning occurring, other than the desired vertical orientation (fully in line with the rudder post tubes). When this occurs the forces applied to the rudder 'neck' must go through the roof and breakage or at least bending of the tangs must become much more likely. I think it's still a pretty strong system and most of the time any bending or splaying has been reported, the most likely cause seems to come down to undesirable slop occurring due to shims not being present and/or the bolt not being snugged down enough. I can still flex mine at the tips but they spring back into position when released (vertical).
Brian, I don't think any angling (I haven't checked mine either) will affect a true parallel alignment of the deployed blades. As I indicate in the following drawings (sorry - no cad capabilities) you could have slightly twisted blade(s) and still arrive at a matching measurement when set up with a rearward orientation.
To do the full monty a long straight-edge is required that must be clamped or shimmed to exactly conform to the rudders center-line. Then the measurements and subsequent corrections to the internal spacer bar can be performed. It would be very interesting to try Steve's on-the-fly adjusting inside while under way. Perhaps, like a car, some tiny toe-in could prove beneficial? Could you lock one off in the straight-ahead position and feel the feedback from the other to find and set the minimum drag?



Now, if I can only dig a deep enough hole for the Dagger-board!

R.

I see what you mean Ross. Yeah, if there is a twist in the actual rudder blade (the top part where the pivot hole is not parallel to the lower blade near the tip) your all-the-way-down method would be more precise. Have you seen this twist in a rudder blade? I guess it would be hard to measure that accurately with the curvy changing profile.

Yeah -to do the same adjustment as Steve's in an X you would have to go below in an M.
I think there is an adjustment under there in an M(?) Never had to do it.

-B.