I confess I am often guilty of surrendering to the adage, "If it ain't broke, don't fix it!" Scheduled maintenance is one thing, but shinning up a 57'foot mast, just because a hurricane is expected is another. Such it was with my ubiquitous Kiss wind generator.
This big heavy wind turbine has been around for 21 years and can still be seen churning out electricity in nearly every marina in the world. It had also worked flawlessly for the ten years I have owned Britannia, and goodness knows how many years before that. It was originally mounted high on the mizzen mast, so when I changed the rig to a schooner I installed it back up the mainmast. The downside is that it was rarely even inspected, that is until a certain whopping great hurricane named Dorian rolled up the Florida eastern seaboard in October 2019. 100 mph gusts were recorded at Cape Canaveral, which is enough to send any wind generator into orbit—even without the aid of the Falcon X rockets, which are now being launched within sight of the marina. Another problem with mounting a wind generator high up a mast is, it can't be restrained in high winds with a rope tether like those which are mounted on a pole aft. The wiring also needs a Mercotac type rotary connector, that allows the Kiss to completely rotate 360 degrees in any direction, and stops the wires from becoming twisted.
I completely stripped Britannia in preparation for the arrival of Dorian, but I forgot about the lonely old Kiss high up on the mast…
When I returned to the boat a few days after the hurricane had continued north on its destructive path, I noticed the genny' was not spinning, even though there was a 15-knot breeze. Something was up, and it looked like it would probably be me—up the mast to investigate
Even though there are steps up both masts, I still find it nerve-wracking to scale Britannia's tall mainmast as my wife tails the halyard around a winch and I slowly climb, with the bosun's chair strapped to my waist. When I finally got to where the machine was mounted, I found the blades could hardly be turned by hand, and felt like the bearings had seized.
I set up a pulley on the triatic stay with a short length of line, so it sat directly above the generator. Then I tied a rope strop around the Kiss body to keep it level so it could be pulled out of its vertical support post. The oval shape of the Kiss body is not conducive to tying a strop to it when swinging fifty feet up a mast on a rope. The support post also stands 33" inches away from the mast, so the blades can clear as they rotate. While I was doing all this I thought, "There has to be a better way than this."
The machine was finally lowered and I lugged it home, to investigate in my air-conditioned workshop. 'Lugged' is the operative word, because the thing weighs as much as a car battery, and the blades are nearly 5' feet in diameter.
I first removed the plastic nose cone. This just screws on the tapered threaded shaft, but as I unscrewed it the cone broke away from its base. (I will explain how I repaired it later). Next, the nine bolts holding the three blades to the hub were removed. The hub was then unscrewed by holding the shaft with a vice grip and unscrewing it.
Four 5½" long screws hold the front casing to the fiberglass body and I was surprised to find they all came out easily, even the last one, which is usually the one Mr. Murphy refuses to release. I then cut out the caulking which seals the front casing to the body and after a bit of leverage with a couple of screwdrivers the cover came off, revealing the inside workings. It looked like a fancy alternator to me, which is more or less what it is.
The outside copper windings are the stator and the rotating bit in the middle is the rotor. The rotor is a very powerful cylindrical magnet, which when spun by the wind, creates an electrical charge in the windings of the stator.
The next question was: how to get this lot out of the body? It was not held in by anything after the four long screws had been removed, so I held the body securely in my bench vice and levered the whole lot out, using pieces of wood as a fulcrum. The stator and rotor came out in one heavy lump, along with the rear bearing. I was then amazed at how light the main fiberglass body was. All the weight is in the stator and rotor, so it is best not to let these drop on your toes, because they might become irreparably damaged, and you might also need new toes.
The front bearing had seized and the rear one looked like it was about to go the same way. I pulled them both off the shaft using a hub puller I bought from an auto parts shop years ago.
In the rear of the stator are the thermostats, which prevent overheating and allow the blades to free-wheel when going berserk in high winds. I tested them with an ohmmeter and they all read zero (0.00), meaning they were likely still working fine. It was then just a question of cleaning everything and buying new bearings and bearing seats. One of the advantages of the Kiss generator is that bearings and seals are available more or less anywhere. I ordered mine from Amazon.com at only $5.00 each.
REPAIR AND REASSEMBLY
I pressed a new front bearing onto the rotor shaft using a bar clamp and a 3/4" inch inside diameter plastic tube. I used the same clamp and a block of wood to locate the rear bearing, both bottomed against lips on the shaft. The rubber bearing seats centralize the bearings in their housings, and the rear one needed to be fitted before the stator was replaced.
Before finally replacing the stator and rotor I decided to try a better way to re-hoist the heavy machine, instead of a clumsy rope strop. I first found the exact horizontal balance point of the assembled machine with the blades attached, which is, (as one might expect), the center vertical axis of the swivel pipe. I then drilled a 5/16" inch hole through the top of the body on this axis and pressed an aluminum threaded insert through the hole from the inside. This had a small shoulder that prevents it from being pulled through by the weight of the Kiss. I sealed around the insert with epoxy, then screwed a 1/4"x 20 TPI stainless steel eye bolt into the insert, after sealing the threads with a few turns of PTFE tape. The Kiss now hangs perfectly level, and safely, from this eye bolt.
The stator was then carefully lined up with the holes for the four screws and pushed into the casing. The rotor then has to be re-inserted inside the stator, very carefully and wearing industrial gloves, because of the magnetism it is hard to push into the windings, until it suddenly decides to let go, and disappears into the winding, hopefully not with one of your fingers.
The front cover has a small dust and water seal in the front, which should be replaced before the cover is bolted back on the body. The old seal is easy to push out and a new one is pressed in. A bearing seating was also inserted in the front cover recess. I masked all around the joint with tape, then caulked it with 3M 4000, then tightened the front cover to produce a watertight seal.
I forgot to number the position of the blades on the hub before they were removed, so it was necessary to re-balance them to ensure a vibration-free rotation, with minimal wind noise. If I had marked them beforehand this would have been unnecessary. Balancing is done using a mandrel supported between two-level benches, through the 5/8" hole in the hub. In an unbalanced assembly, the heaviest blade always rotates to the bottom, I then shaved off a little piece of the lead tape which is glued to the back of that blade. This is repeated until the assembly rotates freely and stops in any position.
I tested the output by connecting the wires from the generator to a multimeter, then spinning the shaft with an electric drill to simulate the wind rotation. The output was up to 28 amps AC. I also made a stronger repair to the two plastic nose cone pieces by pop-riveting them with four tiny rivets.
I used a multimeter to test the six one-way diodes on the rectifier in the control box. These convert the AC output of the generator to DC for the batteries, and they were all reading correctly. I replaced the control box behind the main electrical distribution panel in the saloon.
This completed the reassembly of the actual generator.
REINSTALLING IN A DIFFERENT PLACE.
While rebuilding the machine I decided to look into mounting it on a pole at the back of the boat. I didn't want a repeat of this last hurricane, and have to rebuild the thing once more. If it was on a pole I could actually unscrew the whole blade assembly and the body would just sit there facing into wind with no damage.
I had no pole or support struts, so I placed an add’ on a few of the forums I’m in. A response came from a man in Virginia who had a ten-foot stainless steel chromed pole and supporting struts, but not all the fittings. I struck a deal, but then we found it would cost more than $100 to ship by a common carrier, because it was too long for both UPS and FedEx. I asked the seller if he could cut the pole in half, which he did, and it arrived a few days later. It was 2 ½ “inches diameter, so now I had to figure out a way to splice the two halves together to be strong enough to support a whizzing wind generator weighing 40 Lbs.
I hacksawed 6”inches of one end, then sawed down the length until I had a half inch slot in the piece. It was then a matter of just squeezing the splice together and wedging it 3” into the sawn end of the pip. Before doing this, I market the exact place where the cuts joined, which the seller had made. Next, I drilled and pop-riveted the splice to the tube with five ¼”inch stainless rivets. Then I hammered the other end of the pole into the splice, and riveted that. This produced a join which was hardly noticeable, and about as strong as the rest of the pole.
The kit was missing a couple of end fittings for the struts, and also a base. I bought these at my local marine shop and I was ready to mount the Kiss on top of the pole. This also proved to be a challenge because the diameter of the pole was bigger than the inside diameter of the Kiss. I solved this with a PVC reduction pipe fitting, that slotted exactly into both items.
The kiss generator is supposed to just swivel on top of its support tube, without any bearings, and it took a fair blow to swing the machine into the wind. I made this much easier with a roller bearing that is the same diameter as the inside of the kiss pole, thus reducing the friction to zero. It now rotates at the slightest breath of wind.
Pushing a 9’6”inch pole upright with a 40 lb weight on the end was difficult, but as my wife held it steady I quickly fitted the support struts and made it secure. I did this without the bladed being attached because we didn't actually need the thing to work, since we had marina dock electricity to keep the batteries charged and everything running, and we were still in the middle of the hurricane season, so I didn't want any repeat, thank you!