After installing the overhead panels I thought about what should be the next project. There are so many! . . . . . but most of the ones I could do now will take some time to complete. So, I thought I ought to reward myself with something I can more or less complete in short order after the long effort to complete the overhead panels. Therefore, it seemed like a good time to install the Cape Horn Windvane. I have had the box sitting on the shelf for at least 18 months. It will only take a few days to install the vane. I need to install it to figure out how many blocks I will need for the control lines. Also, once the vane is installed, and the control lines are routed properly, I can then install shelves in the lazerette as well as make additional storage mods under the cockpit sole. In other words, it's probably a good time to install the vane anyway. So, I dug up the measurements I made when I ordered the vane as each vane is custom made for each boat. I spent some time confirming the measurements. I read through the instructions a couple of times.
When I was ready, I started off by marking the center of the transom, vertically and horizontally, with a pencil mark. Then I drilled a small 1/4" pilot hole. I taped over the surrounding area to protect the edges and reduce the likelihood of damage to the Awlgrip paint when I drilled the required 2 1/2" hole with a hole saw. I would be lying if I said I was not a little anxious about drilling this hole. I spent some time making sure the drill bit was level by calibrating the drill with a bronze rod and a torpedo level. Once I was satisfied I knew what level was I installed the hole saw and made the cut. No sweat. The tube fit perfectly level.
Next, I inserted the horizontal mounting tube (HMT). It gets bolted in place with two 1" diameter SS support rods. The rods connect to the HMT on the inside of the lazerette and then to 4"x4"x3/4" beveled plywood pads that are glassed to the inside of boat. Then, to provide more strength, the HMT itself gets glassed to the inside of the transom as well. So, it is important to get the depth of the HMT just right as it become permanent to the boat. To determine the depth, I used a 1/4" line to hold the HMT level (see pictures below) and temporarily installed the control axis (lower part of the vane) which contains the toggle rod and to which the steering oar is also attached. The control axis is inserted through the HMT. The steering quadrant is attached to the forward end of the control axis that protrudes through the forward end of the HMT--a tube inside a tube, if you will. I wanted the vane tower be close to the aft end of the fantail but allow room for the steering oar to rotate up 180 degrees in the stowed position. I also checked that the quadrant, which gets attached to the end of the control axis on the inside of the lazerette, to make sure it will have room to rotate. The quadrant will be in the up position (see the photo below) when the steering oar is down but rotates 180 down when the steering oar is in the stowed, up position. Clear as mud, right? When I get further along and have more pictures it will make more sense.
Once I was satisfied the HMT was in the right position, I marked the tube on the inside with a sharpie. Then, I spent some time cutting the plywood pads that the inside support rods will be secured to. The brackets the tube get bolted two have to be through-bolted to the pads and the flat heads of the machine bolts counter sunk since that side will be glassed to the inside of the hull. I spent about 90 minutes just sitting in the lazerette with the pads, brackets, and some mock up 1" OD PVC pipe determining the best location for the support tubes to be located. I initially thought there would be lots of options regarding where the pads could be glassed to, but not so. The ideal location would have been under the aft deck but the dorades are there. A little closer to the centerline looked great but the lazerette hatch hinges fit there. A little wider and the antenna tuner would be in the way. Finally, I came up with a good location . . . angled down and to the lower side of the transom just aft of the quadrant. By the time I came up with the right location it was time to stop work.
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5 Dec 11 I spent today measuring, cutting and assembling the two support tubes for the horizontal mounting tube (HMT). Much to my disappointment the best place for the support pads was right on top of an old wire run for the lighting ground wire from the backstay chain plate. There was no way around it . . . so I broke out the grinders, suited up and ground down the glass over the wire and removed about a 1' section of wire (I wasn't going to use this wire anyway. Then I vacuumed up the mess. This cost me about 90 minutes.
Next, I made a simple jig for holding round stock when drilling. I took a scrap piece of 2x4 about 14" long and cut 2 opposing 45 degree bevels in it with the bevels joining down the centerline. This created a 1" deep 90 degree angled "trough" that will hold various sized round stock steady for drilling.
Then, I used the measurements for the support tubes from the mock ups I made yesterday. I cut the 7/8" OD SS tubes about 5" long with a hack saw. I used a sharpie to mark on the HMT where the swivel brackets would be located (each swivel is held on with two 1/4" bolts. These holes only go through one side of the tube. Cape Horn supplies a little custom curved and pre-tapped backing plate that fits on the inside of the HMT. I marked the location on the HMT for the two holes for each of the swivel brackets with a center punch. I could not get the jig to fit under my small drill press and have room for the drill bit to clear the 2 1/2" diameter HMT. So, I just set the jig on the floor and cut the 5/16" holes with a hand drill (these holes are cut slightly oversized to provide some wiggle room for fitting) . The jig made it pretty easy. Next, I needed to drill a 1/4" hole for the bolt that would hold one end of the tube to the "U" bracket (I installed the "U" brackets to 4'x4" plywood pads yesterday--see the previous entry for pictures of the pads and "U" brackets). This hole goes all the way through the tube so I used the drill press for the small tube, since it would fit under the drill press, and because this hole needed to be drilled at 90 degrees through both sides. Next, I assembled all the parts and test fit them in the boat. It all looked pretty good. I was running out of time and did not want to get in a hurry epoxying the HMT and the pads in position so I spent the remaining time cutting out biaxial cloth for the pads and a small strip for the HMT. I also spent some time beveling the inside and outside edge of the 2 1/2" hole in the transom. This should allow a better epoxy filet on the inside and a bedding compound caulking grove on the outside. I vigorously sanded the inside of the lazerette where the pads will be secured with 40 grit paper, vacuumed up the residue, and did a thorough acetone wipe down.
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6 Dec 11 Today I completed the epoxy work for the Cape Horn Windvane. But first, a quick look down the horizontal mounting tube (HMT)--see the first picture below. Inside you can see how the little backing plates are recessed (I described them in the previous post). The Teflon bushings on both ends of the HMT provide "stand-off" for the control axis tube that rides on the smaller diameter bushings. The HMT is glassed into the boat and then further supported with the two support tubes that I cut to length yesterday.
So how does the windvane work? The windvane blade is set by the skipper so one edge is directly into the winds. The vane is push over (tilted) left or right as it responds to changes in the relative angle of the wind as the boat sails along. The vane blade is linked to the steering oar via a special connecting rod. A change in the windvane causes the steering oar to turn (left or right) and the water pressure then pushes on the steering oar (with great power) literally swinging the whole oar blade. The swinging of the steering oar (levering is probably a better word) causes the control axis to rotate inside the HMT, riding on those Teflon bushings. That rotation of the control axis is transmitted to the quadrant (bolted to the forward end of the control axis) you can see in the last picture. As the quadrant rotates it pulls on the control lines (they are not rigged in the photo below) that lead, via a series of small blocks, to either the tiller, wheel, or the boat's steering quadrant (if it has one) (three options) as you desire. It's all about the Cape Horn quadrant pulling on the control lines. That is essentially how the vane steers the boat.
Last, night I sanded the HMT on the outside in the area that will be glassed to the inside of the hole in the transom. Sanding the SS tube gives the epoxy something to grab onto so it won't slip. I also sanded the bottom of the plywood pads and the beveled sides with 40 grit abrasive paper. This morning, I started off by test fitting the whole lash up one more time. Next, I performed another acetone wash down of the area that will receive epoxy. Next, I cut some 17.08 biaxial to fit over the plywood pads that will be glassed to the inside of the lazerette. Then, I wetted out the bottoms of the pads and the area against the hull they will contact with. I let it cure till it was tacky. Next, I mixed up a batch of West Epoxy that I thickened with a small amount of 404 filler and the rest was 406 colloidal silica. I trowled it on to the bottom of the pad to create a small wedge to better angle the bad towards the HMT. I smoothed fillets around the pads and too the left over epoxy to make a fillet around the HMT on the inside of the hull where it passes through the transom.
I let all this cure till it was firm but not hard. Then, I removed the bolts from the pad end of the support tube and folded the tubes out of the way. Next, I wet out the biaxial, placed it over the pads, around the HMT, and smoothed it all out. I spent the rest of the afternoon reading through the directions for mounting the control tower and rigging the control lines.
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7 Dec 11 The weather was fantastic today--75 degrees and sunny. It was very pleasant to be working outside. Today, I finished installing the Cape Horn Windvane. I started off the day's work by making a mock up of the windvane tower support tubes with some scrap PVC pipe. I didn't want the support tubes to dominate the stern of the boat--too many SS tubes. Anyway, I kept the angles about 45 degrees and worked around the backing plate under the backstay chainplate. Since I need room for our walker log, perhaps an water generator (someday), maybe a sculling oar, or an outboard I need to keep the aft deck open till I have a better feel for what our needs will be . . . and they will probably change over time. I still need to rig the control lines this week and the course adjustment line (that will be rigged much later).
The most interesting event today was installing the brackets on the tower. The trick was to get the tapped backing plates inside the tube, lined up with the holes I drilled, and the bolts on the fittings to connect with the threaded backing plate. Yves Gelinas, the designer and builder of the Cape Horn Windvane described how to do it in the instruction book. I was a little skeptical but it worked like a champ. Take a look at the pictures to see the technique. I will keep that technique in my bag of tricks.
The windvane is up. It looks good. Seems to be very secure. It is nice to see the boat looking different. Tomorrow, I start working on rigging the control lines. I'll need to pick up some small bullet blocks, make some backing pads and take a closer look how/where to run the lines.
I'll replace the night time photos of the vane in the gallery below tomorrow with some day time shots.
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8 Dec 11 I began the day crawling around in the aft end of the boat thinking about how I will need to route the control lines. For a long time I thought I would run the control line from the windvane quadrant, in the lazerette, out through holes in aft vertical face of the cockpit (above the seat but below the deck the lazerette hatch sits on), along the cockpit coaming, though a small turning block, and then 'thwartship to the tiller--the standard way of attaching a self-steering vane to a tiller steered boat. But when I discussed this with Yves Gelinas, the designer and builder of the Cape Horn Vane he really pressed me to run the lines below the deck and hook it up to the old wheel steering quadrant. His argument is it would free the cockpit of the control lines and put steering pressure low down on the rudder post. Yves is an interesting fellow. He circumnavigated in 1983 with one stop, via the three great capes, on a very similar boat, the Alberg 30. He also did it with the prototype of the gear he now sells, so he knows how the vane's characteristics from personal experience, as well as the enormous strains put on a boat offshore. He also has a very pragmatic "keep it simple" philosophy. I have concerns about the control line running below the deck where I can't see it easily. On the other hand, converting the boat from wheel to tiller steering required me to add an 8-9" long extension to the top of my rudder post secured with a special coupling. So, the idea of the majority of steering pressure being applied low down on the rudder post via the original bronze quadrant appeals to me. Therefore, I'll give Yves' recommendation a try. If I don't like it, I will change it. Tomorrow I'll start making modifications to the steering quadrant, which I fortunately kept, so I can attach the blocks for the control lines.
Note: I mentioned that I think Yves is very clever. In one of the pictures of the Cape Horn steering quadrant I added to the 7 Dec 11 photo gallery, there is a little rod you can see that fits in a special slot in the front of the HMT. It's only purpose is to allow a very small tiller pilot to link to the steering gear. This unique design feature allows what would normally be a low power (and low power draw) tiller pilot to steer a large boat because the tiller pilot taps into the self steering gear mechanical system to provide leverage via the steering oar. Yves points out that because the tiller pilot does not have to work very hard and because it will be in the lazerette and out of the weather it will last longer. The rod can be removed in a couple of seconds.
11 Dec 11 For the last couple of days I have continued to work on the wind vane installation. All I need to do is run the control lines. There are three things I need to accomplish this: the right kind of blocks, 1/4" line, and most important, a way to attach the blocks to the rudder post steering quadrant.
I found the blocks I needed--Harken #001 swivel bullet blocks with a 2 .25 diameter sheave. As hard as it is to believe, of all the places I looked, the best price, by far, is West Marine. They gave me a bunch of discounts. They had two in stock so I purchased them and ordered the rest. I chose bullet blocks because they have very little friction which will help to keep the vane sensitive in light air.
The loop in the line would be run through a block attached to a block bolted to the center of the bronze plate.
The blocks get connected to eye straps that are then secured to plywood pads that are glassed to the underside of the deck or wherever they need to be to provide the best run for the control line. I rigged up the two blocks I have. The first block that turns the line when it first comes off the Cape Horn quadrant is critical; the lead has to be perfectly fair. I used a hot glue gun to temporarily fasten one to the underside of the deck in the lazerette. I drilled a hole through the bulkhead that separates the lazerette from the port side cockpit locker space and temporarily fastened the second block. The line ran fair through the hole. After going though the second block the line turns downward and run 'thwartship under the cockpit sole and then proceeds to the quadrant via two more blocks. The final run to the quadrant had to be at 90 degrees to the line between the rudder post and where the blocks are attached to the quadrant. Since I did not have any more Harken blocks I dragged out a couple of oversized Schaefer blocks and used them to get a feel for the remaining run to the quadrant. I tried several methods of attaching eybolts and eye straps to my quadrant but could not maintain a fair lead. When I turned the quadrant it would interfere with the opposite block. It was the wedge shape of the quadrant that caused the problem. I briefly considered buying a bronze auto-pilot straight tiller to fasten the blocks too but I was confident there was a way to use the quadrant I have without throwing money at the problem. I spent some time laying under the cockpit sole just looking at what I had to work with. I must have removed and reinstalled the quadrant at least a half dozen times trying different ideas. It was not frustrating at all . . . it is very interesting work. It's basically an engineering challenge. I finally determined I needed to flip the quadrant over and bolt a plate to it so I could attach the blocks on the underside of the quadrant and get a fair lead to the lateral bulkhead. Keep in mind I am only working on the port side control line until I figure out what will work. The starboard side will get rigged in the same manner. I had a scrap piece of bronze that I cut with my Bosch jigsaw and then bolted it with two 3/8" SS cap head bolts to the quadrant. Since I needed to flip the quadrant upside down I drilled two 3/16" holes near the lowest portion of the inverted quadrant so any water that drips onto the quadrant will run back and out the holes.
On the right side of the picture you can see the temporary piece of scrap pine 2x4, installed vertically, secured with hot glue and the Schaefer blocks that I used to develop the run. I have not drilled a hole in the center of the bronze plate as I need to get the right fitting--a SS eyebolt I think. Two block will be secured to it--one that supports the port side control line and one that support the starboard side control line. I can't really do much more till the rest of the blocks arrive. So, tomorrow I'll go back to work on the interior.
21 Dec 11 The installation of the Cape Horn Integrated Self-Steering System Windvane is complete. I drilled the holes in the front vertical face of the cockpit foot well for the control lines and Harken #150 Cam-Cleats last night. Then, I bedded the cam-cleats in Life Caulk. This morning I trimmed the excess bedding compound and installed the control lines. I used one continuous line which is not the way it will remain--each line will have a figure eight or stopper knot in the end. After playing with the system a little I have decided I need to replace the 1/4" stay-set with spectra or vectran cored line, or something similar, that has minimal stretch. I don't want to cut a line I can use for something else so I just installed the stay-set as one continious line. The control line run length is about 17' per side for which the line needs to be about 19' long. I have never sailed with this system but it seems to me this is a pretty long run of line to remain maximally sensitive in light air. With all the blocks (5 per side) and turns there is a greater chance for line stretch and block sag. The course adjustment line still needs to be rigged--very simple--but I will not rig it until the boat is completed. It's a very small diameter line that runs from the quadrant to whereever you want and allows one to make adjustments to the angle of the windvane blade. Adjusting the line will change the course of the boat. Other than installing the course adjusting line, it's good to go. Once I build storage shelves in the lazerette and cockpit lockers I will paint the the lockers and the space under the cockpit sole. For now, I am declaring victory. "So it is said, so it is written, so it is done."
I temporarily installed the tiller to see how the system worked.
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I am not 100 percent confident that running the long line with all the blocks is the right answer for the Far Reach. With a tiller I could run the control lines from the quadrant in the lazerette to the first turning block, make a near 90 degree turn, exit out through the 6" high vertical face at the back of the cockpit, run the line along the coaming to another block, and then to the tiller 16" forward of the rudder post axis. The line would be 7-8' long and require only two blocks per side. It would not take up that much of the cockpit. But Yves Gelinas, for whom I have much respect, thinks this is the right way to go. As I mentioned before, there are several advantages to routing the lines in this manner and steering the boat through the original quadrant. First, the original quadrant is bolted onto the rudder post between the rudder post stuffing box and the upper pillow block. This is where the rudder post has the most support and where steering torque will be best mitigated. Second, steering the boat this way eliminates pressure on the tiller head and the coupling that connects the rudder post extension to the rudder post (though I think it is very strong). The extension was necessary to convert the Far Reach from wheel to tiller steering. Third, if for some reason the tiller, the tiller head, or the coupling should fail the Far Reach can be steered through the Cape Horn windvane and its linkage to the original quadrant. Last, by having the control lines terminate near the top edge of the forward face of the cockpit footwell, (and along with the course adjusting line), the Cape Horn vane can be controlled from the companionway vice from the cockpit.
Will it be sensitive enough to steer the boat in light air when rigged in this manner? Yves seems to think so and that was good enough for me to give it a try. If, however, it is not then I can modify it easily enough and connect it to the tiller.
I have been corresponding with Yves Gelinas, the designer and builder of the Cape Horn windvane. He was pleased with the way we installed the windvane but suggested we eliminate one of the 90 degree bends in the control lines between the steering quadrant and the cam-cleats. He said by eliminating that one bend that it will be easier to pull the slack from the lines when we engage the steering system. The pictures to the right are the before and after. I'll remove the extra fair-leads in the next couple of days.
The "after" picture makes it look like the lines are running right from the quadrant behind me but they are angled in from the outside longitudinal bulkheads to these two center fair-leads.
The "before" picture. Yves Gelinas suggested we not use the outside fair-leads for the control lines.
