Aug 30 2007
I finally got off my butt and finished taking apart the Aries Windvane that we affectionately call "Harvey." The Aries is best described as a wind-directed, water-drive autopilot.
Harvey normally rides as the very last contraption mounted on Galena's boomkin. As seen here:
Way back in the spring of '06, during the northbound leg of our BVI trip Harvey stopped working. That is, over a period of a month or so he began to loose his way. He would start off OK, then slowly he would wander off course. Inspection (yeah, I do that sometimes) showed that the main shaft (Item #63 in the parts drawing below) holding the servo-rudder was sticking and was hard to rotate. In fact, by May of 06 it was just about frozen in place.
Last winter I took Harvey home and promised to rebuild him. I had the kit; I had the technology... But there was one big problem. The servo rudder spindle (#59) was corroded in place. Also, as I removed the mounting clamps, the pretty much fell apart. Two of the four clamp caps were broken.
The Aries is built almost entirely out of cast aluminum and stainless steel. As we all know that leads to what? Right: galvanic corrosion. The different metals, in the presence of salt water, make up their own little battery. The aluminum corrodes. When aluminum corrodes it forms a white, crusty, very hard, powder. This powder is aluminum oxide. Yes, that same stuff they use for abrassive on sand paper. The servo rudder spindle (#63) rides in teflon bushings (#53) inside the servo rudder casing (#60). As the aluminum around the bushings corrodes, it expands crushing the bushing tighter and tighter around the spindle. Finally, after 30-years or so, the bushing binds tightly enough to stop the spindle from rotating all together. That was my problem.
The main pivot shaft (#59) has to be driven out of the frame (#50) with a sledge hammer.
I tried but it wouldn't budge. I tried every known penetrating oil. I tried a ten-pound sledge. I hit it hard enough to peen the 1" steel impact wrench socket I was using as a drift. Finally I got out the butane torch and heated the frame. That, plus the sledge, finally drove the pin out.
Then I took a break for a couple of months. I needed to catch my breath
Last night I finished the disassembly and started the actual rebuild.
I got the Lower Bevel Gear (#49) off the top of the servo rudder spindle. There were three set screws and three roll pins holding it in place. Then everything came apart nicely.
I had a rebuild kit that I had found on the boat when I bought her. In it were new bushing, and springs and other "wear-out-able" parts.
To get the old teflon bushings out I used a hacksaw blade and cut them.
As you can see in the photo below the area in the casing that holds the bushing is heavily corroded.
This is the shaft that goes into the bushing:
I disassembled the vane holder frame (#25) and pulled out the pivot shaft (#30). I was surprised to find that all the teflon roller bearings were missing. Also, most of the nylon bearing housing and spacers ((#29, #26) were damaged beyond recognition. It was amazing that it worked at all. And recall, that before Harvey seized up he was steering Galena about 90% of the time we were sailing.
Now I have to put everything back together.
Reassembly only took a couple of evenings. I cleaned all the corrosion out of and off of all the bearing surfaces with wire brushes and scrapers. After that the parts went together without much effort. There was only one part that caused a problem:
At the base of the servo rudder shaft is a retaining ring (#66). The new one that came in the rebuild kit was about 1/8" taller than the old one. I noticed this after I had put the shaft together and was attempting to pin the quadrant gear to the top of the shaft. The holes for the pins wouldn't line up. They were way off. Off by about, well, 1/8". Finally I checked that retaining ring. As you can see there was a discrepancy in the height.
You can also see that the old ring has a rather nasty crack in it. So I really didn't want to reuse it. Since the ring is made of aluminum I figured I could just file it down to the right size. I got out a flat file and started working on it. Once the new ring was the same height as the old ring I used a belt sander to true up the surfaces. Finally I put it all back together and everything lined up just fine.
I was amazed at how smoothly the entire contraption moved with all the new bearings in place. If I can get it properly mounted on the new boomkin he should steer Galena quite well. Even all stiff and corroded he did a great job about 90% of the time. Watch for my log updates starting in November for comments on how the new, improve Harvey performs.
Next came the clamps that hold Harvey to the boomkin. Mine were broken. I e-mailed the people who still sell them (in Denmark) and the cost was about $350 for a set of four. Way too much for me. I found a source on ebay for similar clamps for only $7 each. They are about the same size as the old ones. But the old ones are solid and heavy. The new ones are more of a honeycomb structure. The hole spacing is the same, though. So I'll put the cheap new ones on and take the heavy old ones along as spares.
[The cheap pipe clamps came from Huaan Clamps, an Ebay store seller (http://stores.ebay.com/Huaan-Clamp)]
On the left is the new,
cheap inexpensive clamps.
I'll keep an eye on the clamps. Who knows? These new clamps may work just fine.
[Later Note (July 2008): After 7-months of cruising the Bahamas, the new clamps look fine. The galvanized metal end plate was all rusted, but the clamps were in good shape. Also, I decided that the old clamps had broken when something struck the windvane a rather severe lateral blow (before I bought Galena). The mounting tubes showed evidence of having been bent in some kind of impact. So I saved a couple of hundred bucks. cool...]