BOATWORKS WINDVANE.Indd

BOATWORKS ELECTRONIC WINDVANE SELF-STEERING SOLUTION PENDULUM SERVO GEAR: HOW IT WORKS The pendulum servo gear uses pivoting to leeward. This activates water fl owing past it. If you doubt with it. This steers the boat until water fl ow to beef up raw wind the servo paddle which is really the power, try it with an oar when she is back at the original angle to power. A wind vane is adjusted so a deep blade cutting through the you are buzzing along in the dinghy! the apparent wind. Vane and hence Windvane wonder as to ‘feather’ when the boat is on water beneath the windvane. The This swinging movement to one paddle now return to the ‘feather’ course. When she wanders, the paddle is hinged fore and aft, so that side is transferred to the helm by position and the process ceases until vane receives wind on one side or as it is twisted off the ‘feathering’ lines joining the paddle to the tiller repeated again. With decent gear Electric self-steering tiller systems have their shortcomings, veryone enjoys steering on summer the other. Whether vertically or position by the vane, it is kicked up (or to a drum on the wheel). As the you’ll steer a surprisingly straight as do windwane set-ups. Join the two together and you afternoons, but most of us would horizontally mounted, it reacts by sideways like a pendulum by the paddle is displaced, it drags the helm course in most conditions. agree that the job deteriorates into have the best of both worlds, says Tom Cunliffe a chore after the fi rst few hours. EDiscounting miracle workers like pioneering Cruising my boat Westernman shorthanded struggle in fresh winds or awkward seas. the mighty tiller across, all the pilot now had to solo circumnavigator Joshua Slocum in Spray, would be a bit of a grunt without self-steering. Initially, I set up the big Raymarine Autohelm do was tweak the servo paddle. No longer driven it was the fi rst singlehanded races in the 1960s Before the windvane gear, three of us helmed ST4000 directly onto the tiller. It simply could not by the wind, the paddle of the steering gear was that fi nally cracked the self-steering nut. Sir her across the North Atlantic and by the time cope with the forces and looked like a mistaken adjusted continually by the Autohelm set to a Francis Chichester’s idea of a small sail pulling we arrived off the Scillies with the fourth gale of purchase until one day I noticed a small hole compass heading. Because the arrangement is the helm missed the bull’s eye by a mile, but the trip blowing itself out, we felt as though we’d engineered in my Windpilot vane gear. It looked equally effective when sailing, I don’t use the vane Blondie Hasler’s ‘pendulum servo’ wheeze been in the gym with the Devil as personal trainer. as though it would accept the tiny stainless pin at all unless the wind is solid and unchanging. carried the day with a touch of genius. It still It isn’t that she’s badly balanced, it’s just that supplied by the Autohelm manufacturers to The only refi nement has been a short length forms the basis of many systems, including she is a 20-ton gaffer with a very of shock cord to hold the socket my own Windpilot. These set-ups have their big rig. Her rudder angles aren’t of the ‘tiller end’ of the pilot onto limitations but with a little ingenuity they can excessive, but the 7ft iron tiller ‘Rather than trying to shove the the horizontally mounted pin on be modifi ed to cope with almost anything. needs a relieving tackle in more tiller across, all the pilot had to the windvane mechanism. Battery than Force 4. drain is negligible because the If you’re thinking my boat is do was tweak the servo paddle’ diminutive motor in the Autohelm irrelevant to yours, consider this: hands all the tough stuff straight if Westernman can be induced to self-steer, the set into the tiller to accept the small socket on over to the pendulum servo paddle. This revels in same arrangement will be a cake-walk for a their pilot. I had a spare and it fi tted perfectly. its labour. The faster we go, the harder it pulls, and modern yacht. Obviously the hole was there for just this the boat steers herself without fuss for thousands The Windpilot copes well in a steady breeze, purpose, so I epoxied it in with ‘Araldite Rapid’. of miles. It’s quiet because the autopilot noise is but it’s a non-starter if we are motoring and it While the glue was hardening, I offered up the all well aft, and the same unit has worked since isn’t great in the ever-shifting wind strengths and unit, then drilled the hardwood taffrail for the pin 1999 without any maintenance whatever. directions along our coasts. on the other end. Raymarine had even supplied a The Autohelm ST4000 suits Westernman, but We invested in an electronic tiller pilot to take spare bush to set into the hole. most boats will manage fi ne with the tiniest tiller the helm in such situations. These are great bits An hour later I unshipped the windvane and pilot. So why not marry your windvane steering of kit but can drain your batteries and sometimes set up my new unit. Rather than trying to shove and your tiller pilot? They’ll make a great couple. W HOW TO DO-IT-YOURSELF If your windvane is pre-drilled to to mount the pilot on the boat, accept the tiller attachment pin – as something can usually be contrived mine is – that part is easy. If not, by using the pushpit because the you’ll need a drill and sharp bit. loads are almost non-existent. Make the hole a snug fi t because You may need an extension the system will worry away at it for the activating arm of the tiller hour after hour. Attaching the unit. Raymarine supplies one for other end of the unit to a wooden my own unit. Otherwise you’ll capping is easy. Set the tiller mate have to fabricate something out of at its neutral position and offer it wood, plastic or anything else lying up with the outboard end attached around in your shed. The Windpilot’s wooden The pendulum servo gear with the The tiller pilot fi ts into a hole The extendable tiller arm is windvane is easily removed paddle in the water drilled into the wooden capping secured to the Windpilot to the ‘tiller pin’ on the vane gear. Don’t worry if there isn’t space to Mark where the big pin on the allow the arm to run fore and aft, inner end lands on the timberwork, you’ve only to rotate the windvane get hold of a bush from the mechanism as though feathering manufacturers of the tiller mate, the vane and it’ll all line up sweetly. drill for this and drop it in with a It’s a straightforward job that dab of epoxy. you can do in an a hour If you’ve no suitable place or two. OTHER SYSTEMS While my own arrangement Hydrovane (www.hydrovane. LEFT: Raymarine’s ST1000 favours the Windpilot (www. com) users have had success Autohelm. FAR LEFT: This S1 windpilot.com) and a Raymarine without the added power of the has superseded Autohelm (www.raymarine.com), pendulum servo. This gear favours the ST4000 there’s no reason why the same a balanced auxiliary rudder and method cannot be used with I’m told it works a treat powered As the tiller arm extends or retracts Steering lines run from the The lines pass through blocks to The fi nished installation combines similar windvane systems or pilots. by Autohelm instead of the vane. paddle is twisted Windpilot through the transom Westernman’s 7ft iron tiller electronics with water power 90 www.yachtingmonthly.com • MONTH 2007 MONTH 2007 • www.yachtingmonthly.com 91.

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