WindPilot Pacific Light

[SeaSlug]

I have recently installed a new Pacific Light wind vane from WindPilot, on my double-ender Grinde (Danish make). After much measuring and contemplating I built a custom stainless steel frame and mounted the Pacific Light on it. The problem is that when underway the dynamic waterline rises considerably and most of the van's rudder blade and mount are underwater. Turbulence off the trailing edge of the main rudder means that here is a lot of "shaking" and I'm concerned that over time this will cause wear and tear on the mounting bracket and entire unit. Does anyone out there have similar problems or concerns. Re-mounting the unit higher involves considerable rebuilding of the mounting bracket, but cutting the wind vane's rudder stock is clearly an options. But before I do that I was wandering what the "global community" had to say.
Sea Slug
Here's a YouTube video of the problem

https://www.youtube.com/watch?v=wwxK26Pqxro

[roverhi]

The top of the servo rudder should be above the resting water line by 6" or more. Boats squat at the stern when underway so the self steering rudder blade spends its life under water even mounted properly. If yours is set up with the servo rudder head out of the water at rest, then all should be fine. From the video, it seems to be working without any issues. Didn't notice excessive shaking or vibration.

Assume the video was taken under sail with the engine not running. Depending on the boat, servo pendulum self steering may not work well because of turbulence from the prop when under power. Our old Aries with a non kick up servo rudder would shake like crazy if centered with the engine on. Would swing the rudder all the way to one side to stop the vibration when powering. The prop on that boat was only a few feet from the rudder.

I have a WindPilot Pacific Plus that I bought second hand off a much larger boat. Mounted it as high as I could but the steering rudder head was just below the water and the aluminum rudder coupling was constantly getting dunked with even little wave action. It worked fine including a sail to Hawaii but the coupling being constantly wet caused corrosion problems with the cinch bolts. Took the vane to a machinist and had the support casting and rudder axle machined about 8" shorter so it now lives higher and drier. Still works fine. If it's possible to cut a few inches off the shaft to get the at rest height better, probably wouldn't be a problem. Might check with Peter before you do it though.

[SeaSlug]

Roverhi
Thank you for your prompt comments, yes I have been in contact with Peter at WindPilot, and cutting the pendulum rudder stock is certainly an option, although I should also elctropolish the cut to avoid excessive corrosion due to the salt water. Under sail at anything over 5-6 knots (certainly in any amount of wave action) means the entire pendulum rudder it's head and indeed at least half the pendulum arm tube (stock) are underwater and effected by turbulence thus enhancing the "shake". I suspect that if only the pendulum rudder blade is in the water underway the "shake" will be greatly reduced. I will post a response to what I do and if it indeed works.
Thanks again for your comments