Off center rudder on R27

[Toki]

There's another thread I started over in the tech section on this: http://www.tugnuts.com/viewtopic.php?f=5&t=13048 , but I figured this now belongs in the "ask the factory" section.

I'm trying to buy a 2016 Ranger 27. One of the findings during the sea trial was that it seemed to have very different steering characteristics port Vs starboard. Upon examination we found the rudder was way off center. It would go ~45 degrees to port but only ~20 degrees to starboard. I asked that this be fixed before closing. The mechanic agreed that something was way off here, but couldn't see any adjustment or damage. He called the Ranger factory and was told "That's normal, that's how all R27's and R25's are". So, a couple questions:

Ranger factory: is this true? Why would the rudder be designed like this?

R27 and R25 owners: are your rudders all way off center like this?

Thanks all!

 

[bob daily]

Toki
What a unusual problem I'm surprised you have not gotten more feed back, if it was me I would negotiate a lower price for the boat, then remove the bracket that attaches the hydraulic ram to the tiller arm and replace with one a few inches longer that would place the rudder midship when piston was half way out.
A good machine shop would cost a lot less than what you could save on the price of the boat!
Just my thoughts, good luck Bob

 

[Toki]

Thanks Bob, yes, it's an unusual problem ... but maybe not! Here's a little more data:

The broker's mechanic called Ranger tech support and says he was told this is normal for all R27s and R25s. Something about requiring clearance for the prop shaft.

I called the Ranger factory tech support. I was told that yes, the rudder is mounted slightly off center to accommodate the prop shaft, but this is physical mounting location, not rudder travel. He thought this particular situation sounded strange and rudder travel should be centered.

The seller is saying it's normal, it came out of the factory this way, it's how all R27s are, so he's not willing to repair it or renegotiate price.

There is some urgency to closing on this boat, so I'm asking that the seller provide a statement saying that if it can be shown conclusively that this is correct per design, I'll accept it. But if that can't be shown, he'll pay for the repair.

I'm hoping someone from Ranger pipes in on this thread to offer an opinion.

And I'm REALLY hoping some of you R27 owners will offer your observations. This is real easy to check; pull the container out of the rear bench, turn the wheel stop to stop, and see how far that tiller travels port Vs starboard.

 

[bob daily]

Good luck, and remember she's not the only pretty girl in town, be satisfied with what you pay for!

 

[allanrs74@gmail.com]

Toki,

This seems like a very easy question for Andrew or Kenny at Ranger Tugs to answer.

Question:
Should the rudder travel an equal distance(or arc) from amidships to both port or starboard when the wheel is turned from stop to stop?

I would check my R-27C, but I'm 2500 miles away from my boat. I would be very, very suspicious about it traveling further on one side or the other. The thread about the rudder being offset is a red herring. It has nothing to do with the travel of the rudder but does allow removing the prop.

I am very curious to hear the answer to your question.

Regards,
Bob Allan
Annie M

 

[S. Todd]

We have a 2015 R25SC and the rudder is mounted off center (to the starboard) from the prop so that if necessary the prop shaft can be removed without removal of the rudder. Your description indicates a different issue in that the rudder does not turn the same distance to the port or starboard. That is not normal based on the way my boat and I understand most of the boats are built. When the rudder is centered you should be able to turn the wheel at the helm an equal number of turns from center to either port or starboard. There is an adjustment nut where the steering cylinder attaches to the rudder arm under the stern seat. Is this boat's loose or somehow misaligned? Maybe you should take a photo of it under the stern seat and post it for Andrew or Kenny.

 

[NorthernFocus]

I think your terminology of describing it as an "off center rudder" is adding confusion to the situation. You described it properly in the first post but keep referring to it as "off center". Off center may well be by design but turning 45 degrees to port and only 20 degrees to starboard is fairly unique if done intentionally. Though on reflection it is built on the left coast so maybe turning twice as hard to port is indeed intentional :?

 

[bob daily]

Toki
You might want to go check the manufacture of your steering system, telflex , u flex, or seastar company. Easy to do just check out what system is installed on board.
This might be as easy of fix as ordering a longer clevis for the hydraulic ram to hook up to the tiller.
The seller might of been told this is normal on this boat as to why he's not working with you.
I find it hard to understand why someone would risk the sale of that much Mooney over a $25 part?

 

[BB marine]

It is located in a tight spot but completely repairable. I have no idea the reasoning of having a strong port steering and weak Starboard. Just a guess the wrong cylinder was being installed. There is more to lengthening the cylinder or moving the mounting position to correct the issue. Normal steering setups are 70 degree or 90 degree, center being 0 - 35 degree equal port/starboard or center 0- 45 degrees port and starboard. The positioning of the ram is important to provide the proper Ram offset to prevent rudder "fold over" keeping stresses on the steering system manageable with enough leverage for safe operation. This is done when the boats steering system is designed by the manufacturer. If what the owner of the Tug said all 25 and 27 Tugs were set up this way there should be a reason why. If there isn't this may be a steering problem issue with a lot of Tugs. Hopefully the Service advisors at Fluid motion will chime in on what the reasoning is. If I was making the purchase ( My opinion) it would be difficult to accept the boat knowing this issue unless I received a good explanation of why or what the fix is if any. What is the opinion of the surveyor? I assume he was a ABYC and Sams certified surveyor?

 

[Toki]

Thanks for the replies everyone. I'm still hoping one of you R27 owners will be able to make a quick check of your rudder angles to confirm if indeed "all R27's have a 25 degree offset rudder angle".

The factory has been contacted about this, but in fairness to them I wanted to give them the chance to chime in on this thread before providing details on those discussions. But I'm now getting enough feedback from the rest of you that indicates this is NOT normal that I'll describe that communication.

The broker's mechanic contacted the factory and talked to Ivan. Ivan said "yes, the offset rudder is per design to allow for prop shaft access".

I called the factory and talked to Kenny. He confirmed that yes the location of the rudder is slightly offset, but he thought the offset rudder swing was unusual. He said from a rudder neutral position there should be equal wheel turn stop to stop port to staboard (in this case it's ~half the rotations one side Vs the other side).

I mentioned this to the broker. He had his mechanic talk to Kenny. Kenny said Ivan is senior to him and to believe what Ivan said as he is more experienced with the older models.

So that's where I am with the factory. In order to close on this boat, I insisted on a letter from the seller/broker stating that if it can be shown that this offset rudder travel is not per spec, they'll pay for the repairs.

 

[allanrs74@gmail.com]

Toki,
It sounds like Kenny answered your question. The rudder should travel the same number of turns or distance from the midship position. And yes, the rudder post is offset from the centerline to allow pulling the prop and shaft. As I stated earlier, this is a red herring concerning your problem.

Any boat that does not turn as quickly or efficiently on both sides is not right. I hope you kept some money in escrow to fix your problem. From what you have passed on from Kenny, it sounds like Fluid Motion has confirmed it is not right.

Good luck getting it rectified.
Bob Allan
Annie M

 

[NorthernFocus]

Hmmm. The early boats(like mine) don't have an offset rudder.

 

[bob daily]

I'm surprised the factory has not posted any comments about this problem, as it seems to be a safety issue for maneuvering in tight waters, docking ! I realize most owners depend on there thrusters, but during a failure it would be nice to have full steerage capabilities! If a design flaw from moving the rudder for offset, all that would be required is to extend the clevis by the same distance as the offset! About a $25 part, and looking at the pictures a lot easier to replace than some models.
I have been impressed with the support that I've received from all at Ranger Tugs that is why I'm confused as to no response and solution!

 

[BB marine]

It can be a safety component if it wasn't engineered and tested to be positioned where it is now. It can also be more then a $25.00 part. The steering system has calculated forces on the rudder. The cylinder manufacture has engineered the cylinder and its components to except the the calculated forces and has specifications for cylinder location and maximum rudder offset. If using the same throw cylinder I would not change the components of the cylinder unless designed by the cylinder manufacturer .A mounting location change would be more desirable. But it would still require calculating the proper Ram offset angle. This information can be available from the cylinder manufacturer or preferably from the design engineers from Fluid Motion. Before I would make modifications I would get assistance from Fluid Motion. The existing installed system while questionable seems to have not caused a safety issue and if it does the liability would be put on Fluid Motion. If a third party does alterations that releases the liability to the third party. Install design confirmation stating it is designed this way because..... or we were not aware of this and this is what we are going to do to improve the issue..... from Fluid Motion would be a good information for all R27 owners.

 

[bob daily]

B B
You are correct, however the company that manufacturers the steering system supplies various sizes Cleves for the same system (hydraulic cylinder), there is adjustment on each unit for small amount of alignment. Yes the factory and there engineers should review and come up with a solution and let others be notified. This is a safety problem as a lack of proper steering is a accident waiting to happen!
I would hope this is fixed soon, let's not wait for a problem (accident) prior to fixing.

 

[NorthernFocus]

...If a design flaw from moving the rudder for offset, all that would be required is to extend the clevis by the same distance as the offset!...

That was my initial thought as voiced in the other thread on this topic. But that was before the information about the rudder offset came up. If in fact the rudder was offset without changing the mounting position of the cylinder, then extending the clevis takes it in the wrong direction. The clevis/ram arm needs to be shorter or the cylinder moved farther from the rudder.

...A mounting location change would be more desirable. But it would still require calculating the proper Ram offset angle...

Simply relocating the ram mount by the same offset that the rudder was moved would effectively be the same configuration as the original design. Unless of course consideration is made for the different hydrodynamic loads on the rudder due to it's being offset behind the wheel. But somehow I'm doubting anyone did those calculations. And not sure anyone would for a 27ft boat.

 

[bob daily]

If you look at TOKI's pictures that he posted on prior post you will see with ram fully extended there is not enough travel.

 

[NorthernFocus]

If you look at TOKI's pictures that he posted on prior post you will see with ram fully extended there is not enough travel.

My bad. Should have gone back and looked again rather than deciphering all the text(turning to port vs tiller to port etc). So the original recommendation (which we've both made now)is still good. Also in the photos it is clearly evident that the rudder is offset to starboard.

But now it is even more confusing as to how the factory did such a thing. Moved the rudder towards the ram and it's too far away. Miscalculated the relocated mounting point or changed rams? Since they're not chiming in all we can do is speculate :?

 

[Craig]

I would guess the reason that the factory has not entered the conversation is because they are all hands on deck in Anacortes at the boat show.


Sent from my iPad using Tapatalk

 

[BB marine]

...If a design flaw from moving the rudder for offset, all that would be required is to extend the clevis by the same distance as the offset!...

That was my initial thought as voiced in the other thread on this topic. But that was before the information about the rudder offset came up. If in fact the rudder was offset without changing the mounting position of the cylinder, then extending the clevis takes it in the wrong direction. The clevis/ram arm needs to be shorter or the cylinder moved farther from the rudder.

...A mounting location change would be more desirable. But it would still require calculating the proper Ram offset angle...

Simply relocating the ram mount by the same offset that the rudder was moved would effectively be the same configuration as the original design. Unless of course consideration is made for the different hydrodynamic loads on the rudder due to it's being offset behind the wheel. But somehow I'm doubting anyone did those calculations. And not sure anyone would for a 27ft boat.

The calculations for the most part are already done by the manufacturer of the Hydraulic ram. There are several illustrations provided in the installation manual of all marine Hydraulic systems. The installer needs to measure and apply the proper configuration for the installation in the given boat. To add a component or just move a cylinder may be feasible but confirming it meets the manufactures guidelines would be advisable. I hope every boat manufacture does this regardless of the boat size.
The clevis at the end of the cylinder is not an adjusting point. It is threaded on to the cylinder and requires a full thread engagement. There may be different clevises available to thread on the cylinder but these are not meant to be used for adjustments.

To achieve MAXIMUM cylinder performance it is suggested that an imaginary line is drawn though the tiller arm hole at both hard over positions. This will create the “cylinder center line”. With the tiller arm at hard over positions, angle X and Y should be the same. X=35 degrees or 45 degrees and Y =35 degrees or 45 degrees.

There is NO adjustment for centering cylinder after installation. Correct mounting is critical at this time.
You will find these two statements in bold at the beginning of the installation manual.

I'm going to take a guess here and say that Fluid Motion did all the calculations correct and installs the Cylinders in the correct position but may have received the wrong cylinder lengths and installed them in the boat in this topic and maybe other boats. Just a guess. Easy fix if thats the case. Ok I'm done speculating!