Edson Steering System For Windvane

[acove]

I certainly agree with you, SVTatia. Each boat needs to be evaluated on a case by case basis. I think you will even note that in the quote you used from my last post that I stated "the lifespan of steering equipment can vary greatly." It sounds like you have taken very good care of your equipment and this level of maintenance is paying dividends.

The 30 years that I mentioned came from the first post on this thread. From experience in the field, I would say this is a good average for chain & wire and drag link style pedestals, but by no means a hard line. The example you used of the build that took 10 years outlines an exception very well. On the other end of things, there could be a boat that was raced very hard and put away wet, with some neglect for the equipment onboard, and the pedestal may need replacing after only 15 years. Until you are able to go through an inspection on a particular boat, you just can't know. As a side note, I have seen most rack and pinion and work gear systems last for longer than the systems we are discussing, but they do have their limitations, and it also depends on use and maintenance.

Although a pedestal can be inspected fairly well with the naked eye, there are some systems, or system components that cannot. One example of this is stainless components that are susceptible to crevice corrosion (ig: standing rigging). I do not have the equipment (ie: x-ray machine to do it right) to scan the swages for crevice corrosion, so I opt for a safe replacement schedule. If I had access to test equipment, where it would be cheaper than replacement, it is almost worth considering it, but at the end of the day I think the replacement cost is worth keeping my family, friends, and myself safe. Losing a rig is not fun, safe, or cheap, and I have already been there more times than I would like.

Thanks for the comments on my post, SVTatia. Well stated on variable lifespans of equipment. I would love to see more equipment really built to last a lifetime, but I'm afraid that very few of us would be able to afford it in the first place. I've seen a few bronze pedestals around...

[acove]

On another note, SVTatia, I really appreciate your taste in style. I also own a Luders 33. I have hull #80 out on the East coast. Glad to meet another owner - hope to catch you around sometime.

Looks like you're enjoying the benefits of freshwater in Toronto

[Suijin]

Originally Posted by acove

...Well, Edson customer service was spot on with their recomendation, because a windvane autopilot Pulls in either one direction on the wheel shaft, or back and forth. This causes uneven wear and will elongate the bearing housing over time (oval wear pattern) - hand steering distributes the loads more evenly. The extra bearing in the 400 series and bearing liners distribute this offset load.

I don't understand this. The Monitor lines run to the wheel adapter, which is clamped to the wheel. Why is this any different than two human hands on the wheel in terms of action and/or forces? They too "pull in either one direction or back and forth". The shaft is the shaft...why does the method of applying torque to it matter if both of them are being translated through the wheel itself? If anything, because the wheel adapter is @ 1" recessed from the wheel on the shaft, I would think that it would exert less stress on the shaft.

Please explain.

EDIT: On further thought I think I understand what you are saying. Hands on the wheel turn the wheel without applying any lateral force to the shaft. The Monitor, because the pullys are fixed, apply lateral force from one fixed direction, thereby causing asymmetrical wear on the the bearings. Is that it?

This is germaine to me because my YS pedestal is 27 years old and getting sloppy.

[acove]

Glad to explain, Suijin. I think you were starting to get to it with the edit at the bottom of your post.

Let me start with looking at the forces when hand steering. In order to turn the wheel shaft, a torque (purely rotational force) needs to be applied. To accomplish this, the helmsman places a hand on the wheel rim and turns it. When turning the wheel from a single point on the rim, a torque is applied to the wheel shaft, but there is also a linear force being applied to the shaft. This force is parallel to the tangent line of the rim where the force is being applied. So, if the helmsman's hand is at the top of the wheel and they are turning right, the force that they are applying to turn the wheel is also a being applied to the wheel shaft to the right (this force is equivalent to them just pushing the wheel shaft to the right, without the wheel being there). Now, if the helmsman has two hands on the wheel, the torque being applied is shared between their hands, but there are two separate linear forces also being applied perpendicular to the wheel shaft (say, on slightly down and to the right and another just to the right). This force places additional load onto the wheel shaft bearings - and mostly the aft bearing (There is also another moment load the bearings must handle that is related to the length of the exposed shaft, but that is significantly less in most cases and we'll ignore it for the purposes of this discussion). Now, when hand steering, the skippers hands are never in the same postion, they will move depending upon if they are sitting or standing, or even if they just want to shift their arms. So, the wear that is caused by this additional force is spread out considerably around the bearing housing - this means a slower and more uniform wear all the way around the bearing housing.

Note that there is also loading on the wheel shaft from the chain, but this is distributed evenly across both bearings. This means less wear, since it is distributed over a larger surface area, just like the double aft bearings do on the 400 series Edson pedestal for wheel loads.

Now, in moving to windvane steering. As Suijin mentioned, the lead into the wheel is fixed, so the lateral loads are always in the same direction. This means that the bearing housing will be worn more in one direction than another. To further aggregate this issue, the wheel adapter for the windvane is smaller in diameter than the steering wheel, so a larger force must be applied to turn the wheel. This also means larger linear forces, so even more wear. Again, a double bearing and stainless bearing liners attempt to mitigate this problem (as in the 400 series pedestal).

I hope that addresses your questions, but let me know if you need further clarification anywhere. I know some of this was written a little heavy in engineering lingo. Given you have a YS pedestal, it is possible the wear is only in the shaft bushings. They did not use needle bearings, just bushings, to the best of my knowledge. So, if the bearing housing is still in good shape, new bushings may tighten it all right up - the only problem is trying to source these. It may or may not be worth it... in most cases it is the latter. You will have to take a close look to see where the wear is located.

[SVTatia]

Originally Posted by acove

On another note, SVTatia, I really appreciate your taste in style. I also own a Luders 33. I have hull #80 out on the East coast. Glad to meet another owner - hope to catch you around sometime.

Looks like you're enjoying the benefits of freshwater in Toronto

Agree with you on the previous posts, well said.

My boat is now temporarily enjoying fresh water, but she was on the US East Coast and exposed to salt environment most of its life, until I bought it 4 years ago - it was based in Connecticut.
Now I am restoring most of its system and at the same time understanding what a well built sailboat that is, simple but very solid.