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2 3 ; s bi ae : SS shee af = Ni pim=nasge MOVING CARRIAGE VANE GEAR BY DESIGNED A.Wilcock COPYRIGHT MODEL MAKER 38, — B33 CLARENDON Mg ® wh ta RO, aie i OF PLANS SERVICE WATFORD, axa PERSPEX OR ea CLOSE GRAINED WOOD CURVE NOT ESSENTIAL —T he eet if 4 3 pain sa 4 BACLEAR Sy © 2. 0FF ©}-4 FILED OUT AFTER rl HERTS yon. INITIAL ASSY TO be 42BA ALLOW MORE ROO MOVEMENT TO’P’ _74 DIA.ROD TAPPED 4B.A BOTH ENDS I”X 8 BA (NUT SOLDERED ON) Yq Tar 484 3; 8 B.A – oa TAP 2BA : TAP 2BA © \ 3/3 89 afl SOLDER & RIVET ‘E’ 24″ TO ‘C’ BEFORE TAPPING 4 B.A ae | gf 2BA FIXED SO THAT’AE’ : ENGAGES & DISENGAGES : WITH TAIL OF’c! » -+ 22 pia: —— 1/2 See: AG Beating sheet Twin running ke Ase ae Mie iz sheets 3hq AG. FRICTION WASHERS MADE FROM CYCLE BRAKE— BLOCK MATERIALS oP § \ V8 SLICE FROM 25 TOOTH MECCANO GEAR (20FF) 9/16 OF 28A.ROD BOTH ENDS POINTED 4’ OF 48.4. ROD (2 OFF) 4 B.A. HEXAGONAL NUT (7 OFF) Va” LENGTH oF ’74” TUBE % SCALE FROM BRASS OR FIBRE aT LEAST 1/4 p14 3/4 LENGTH oF 4″ TUBE ° ic — \ ‘ — NxxzecAawmvzEtoD = . ¥2″ WOOD SGREW FIXING 6” BEHIND ‘A’ e 4 V4 OF 48,4 ROD I SCREW 4BA 22 OF 4B.A. ROD 6 B.A. SCREWS AND NUTS (2 OFF) COUNTERWEIGHT BALSA VANE TAPPED 4 B.A. AY | a ya Comes FEBRUARY, 1961 A WELL-PROVED VANE GEAR WHICH ALL YACHTSMEN WILL FIND OF INTEREST BY A. WILCOCK Moving Carriage Vane Gear bridle to the carriage connected but inoperative because the carriage is locked. When reaching and running the beating sheet is unhooked from the deck and hooked to the boom out of the way and the runThis sheet is a double sheet, ning sheet is used. the operative one being connected to an eye plate on the deck, as shown, and the inoperative one to the quadrant (for gybing back) as shown in Fig. 3. Next let us turn to beating on tack and tack. Hook the beating sheet to the loop from the deck (see later for an explanation of the need for the loop). Set the . vane in a fore and aft position, the vane being aft. Turn back the carriage holding catch, so freeing the carriage. If now the boom is put over to starboard the bridle from the beating loop moves the carriage so that its rear end also moves to starboard and with the rudder still central the sun and planet gear action moves the vane twice the number of degrees of the carriage movement. (This is only so with a one to one gear ratio). The carriage movement is arrested and adjusted on either tack by the two screws shown. With the boom held over to starboard as it will be by the wind the movement of the vane in either direction gives positive drive to the rudder to port or starboard as appropriate. (The guy lever at the back should be in the central neutral position for this). When sailing in this condition the tacking of the boat by pole or hand automatically puts the main boom over to port and the bridle to the carriage moves it over against the other stop and the vane, by the sun and planet gear motion, moves to the T is some time since the author last wrote on vane gears and the time seems opportune to look at the latest ideas. Before doing so, however, it is proposed to review what the skilled racing skipper looks for in the “perfect” self tacking vane gear, DAaAhWNe Here is an attempt to specify such a gear:— . It shall be light. . It shall be strong. . It shall be sensitive. . It shall be easily balanced. . It should be positive when tacking. . It should be capable of positive port and staree helm when tacked as well as when . xe qt 7. It should be reliable on guying. 8. Gybing facilities should be available. 9. It should be capable of precise setting. That seems a pretty formidable list. The moving carriage gear about to be described and illustrated meets them all and as such has much to commend it. The gear has been “christened” the moving carriage gear because its basic tack and tack motion is composed of sun and planet gears in a movable carriage. Fig. 1 shows the complete gear while Fig. 2 is a vertically exploded view of its various parts. Fig. 3 “mounts it on a deck and shows the various operating _lines. It will be seen from this that the gear proper is coupled by a push pull rod to the quadrant mounted on the rudder post. The quadrant is used for gybing as will be described later. Full details of all the dimensions of the parts are given on the construction sheet available from Model Maker plans service. Now let us turn to using the gear. _ appropriate angle for the new tack. Guying is affected by using a boom guy and push- ing the guying lever at the back of the gear over to Starting with the same side as the boom guy is fitted. Thus if the boom guy is put to the port side and the guying lever to the port side also, the trim of the boat is for a starboard tack. Set it off on the port tack and the boom guy will be stretched and the beating sheet moves the carriage against the rubber of the guying lever. Both the boom guy and the vane guy are trying to turn the boat back to the starboard tack and will succeed in doing so. How quickly is of course dependent on the strengths of the guys, and how far the vane guy is pushed over, and the strength of tk the lines attached as shown in Fig. 3 and the carriage locked in the central position by the catch at the rear, we have the condition where any movement of the vane, either clockwise or anti-clockwise, is transferred to the rudder through the two gears and push pull rod to the quadrant. In other words we have a simple vane steering gear in which the vane can be set at any angle through the friction joint and it will then give port or starboard helm as the wind on it dictates. When beating, the beating sheet from the boom is led to the central loop on the deck with the 69 ODE ANKIE:R) wind. Experience is required to set these to get the performance required under the varying wind conditions, but this will soon be obtained by practice. By the way, “shirring. elastic” is adequate for the anyway. vane guy and the rudder centring elastic. Reverting for a moment to the loop to which the beating sheet is hooked and the bridle going back to the carriage; the bridle should be just an easy tightness with the beating sheet tight. The pull of If the gears are Finally to adjusting the tack and tack screw limiters. Start with the screws well back, i.e. make the gear force the boat off the wind, and with the sails well in, say 15 deg. to the centre line of the boat, let it go. It should sail a free beat, say 60 deg. to the wind. Move the screws forward slowly so limiting the carriage movement and of course the vane. A point will be reached where the boat heads into the wind and into “irons” if not even going so far as changing to the opposite tack. This is too far and just short of this position will be found one where a speedy close beat is obtained. This adjustment of course must be found for both the screws separately. These positions will be approximately right over all weather conditions, but you must be prepared to adjust them both by small amounts very frequently to get the most out of your boat, the sheet is then taken on the loop and as the boom goes over from one tack to the other the carriage moves easily. To omit the loop puts all the strain on the bridle which will then be found to bind and the carriage motion will be unreliable. So far balance has only been mentioned in the specification and so here we must point out how simple it is. With this type of gear it is only necessary to balance the vane with a counterweight on the friction arm, since the vane carriage is fixed centrally or held offset to one side or the other as when on tack and tack. Balancing is thus most readily effected by removing the friction arm and temporarily fitting it on a rod which is then placed on knife edges, the counterweight then being adjusted to give balance. The uprightness or angle of the vane to the base can easily upset the balance so it is recommended that the bottom of the vane is made flush with the carrying arm to facilitate fixing it each time in its proper Let us finish on two points, one of very practical interest and the other design. place. 1. For the bridle from the central loop to the carriage, Terylene, or a cord unaffected by water, is essential, otherwise between being wet or dry the action will either bind or be too slack. The author would strongly recommend such cord for all sheets Now for a few constructional details. The gear has been made throughout of brass. The author uses this every time. The strip is valance curtain rail, the gears are Meccano 25 tooth gears, and the rest brass (he uses plaited Terylene) so it is not a question of buying a lot for only a foot. B.A. screws. The dimensions are appropriate for a 10 rater or “A” Class; for the smaller classes the same material should be used and weight saved by filing down the strip width a little and also its thickness at points where there is no bearing. A word of warning to those constructors who can produce a precision engineering job. You can have too good a fit when it comes to vane gears. A small amount of sloppiness all round ensures easy working under the arduous conditions of salt water on a hot day, conditions which the author has known to put a precision made job out of commission in the first half hour. This of course is all in favour of the constructor who is not up to making a precision job. To him here is another tip. too tight or too loose at the first attempt of drilling the bearings, bore one of the V cavities right out with say a 3/16 in. drill, plug it with hard brass rod riveted over, and drill another V bearing; this time the circle of the plug is a very good guide for moving the centre of the cavity a little bit to one side of the original drilling. If needs must, this can be done to both the top and bottom bearings. 2. The design has been round gears of 1:1 ratio in which the vane to rudder movement angle ratio can be adjusted by the point (or radius) of attach- “ment to the quadrant ize, with the push pull rod on a 3 in. radius on the gear and pivoted at 14 in. radius on the quadrant a movement of 4 deg. on the vane gives only 2 deg. on the rudder. If of course other gear ratios are used, two things happen (a) the carriage movement for a given vane movement on tack and tack is different and (b) the vane to rudder angle movement ratio is different. In case (a) the smaller gear must be below the vane and the carriage angle to vane angle is given by multi- plying the carriage movement by (1 + gear ratio). So with a 2:1 gear ratio a carriage movement of 15 deg. gives 15 x (1 + 2) = 45 deg. movement of the vane. The movement obtained under a| (b) now becomes a product of the gear ratio and that obtained from the two radii at which the push pull rod is pivoted. From experience the author is in favour of the 1:1 gear ratio and adjustment of the vane to rudder movement ratio by altering the point of attachment of the push pull rod on the quadrant. A 2:1 ratio as shown in the article is a good starting point. It is the varying shapes and sizes of rudders that prevent one being dogmatic about what is right. 70 ILL you make me a boat?” asked my tenyear-old, “Not ‘Can you… ?’.”. The infinite trust of the lad! In the face of this, what could I do? “Sure!” I replied airily, inwardly thanking my lucky stars that he hadn’t suggested a working model of the Coronation Scot or one of the Queens. It is thirty years since I attempted model making, Mentally visualising a foot length of four-by-four, hollowed out and sanded to shape in my small engineering shop in a matter of minutes; with a screwed-on keel made from an old orange-box and melted-down lead soldiers; with sails that had started life as handkerchiefs or an old sheet, I idly drafted an outline on a piece of paper. The shape I saw before me would require (horror upon horror) at least two blocks of four by four—and no knots! I brooded upon this for a day or two, and then, by some happy chance, met up with a neighbour who is a model-making addict. Within minutes of hearing my problem, he planted a great bale of plans in my lap and begged me to take my pick. After burrowing through the pile from one side to the other and then back again, I came to the reluctant but inescapable conclusion that, to the “gen. boys”, any sailing hull less than 36 inches overall just didn’t exist. This seemed enormous to me, but, there you are—the model yacht clubs class it i an elementary junior job—so, 36 inches it had Ohe Birth to of a 36 A light-hearted proves article which be. Three weeks later, I had ruined a barrow-load of good material, and got nowhere in particular. Then another thought struck me. Perhaps I would have more success in my own particular medium—resinbonded glass fibre. It was worth a try, anyway. Gathering together the remnants left over from my previous efforts, I fought my way grimly through a succession of failures and mess-ups until at last a reasonable contour was attained. The next step was to coat it with a workable surface, from which to take a mould. I used a plaster base, then a quarter-inch skin of cellulosebased filler; finishing with several undercoats and topcoats of Belco black. nevertheless instructive for intending glass-fibrites By L. BERNARD HASLEWOOD Crouching, upside down, on a sheet of plate glass, the shape looked most impressive—until I started smoothing off. There’s nothing like a black finish with light undercoat for showing up rough work— and for shattering self-esteem. It was a toss up which showed first—a good, slick surface, or the plaster. The plaster won. * By the end of another week, the second attempt was finished—this time coated with resin, which “wet and dried” down quite satisfactorily. For some time I inwardly debated whether to mould the hull in one piece; with the keel. in whole or in part, separately, to be joined up afterwards, or whether to adopt the more complicated. but more -accurate method of a longitudinal bisection of the whole thing. This would give me a hollow keel. I thought I would put the lead inside the skin. despite the slight lessening of leverage and ccnseauent restriction of sail area that this wou’d entail. Still— it would do for a start. After all—a ten-year-old boy isn’t generally a purist, and mine. far from being critical. was viewing the whole proceeding with a most gratifying awe. ; I “laid on” my plastic laminations, and awaited results. In due course the mould was removed. and the first thing that struck me was a queer transformation 106 FEBRUARY, 1I96] Photos at right show the second hull (top in each picture) and the former. Mottled supearence arises from rubbing own. of the model, or former. In the short space of the drying time it had become cadaverous—in fact, almost skeletal. Inspection of the mould confirmed my suspicions. The plastic, constricting on the former as it hardened, had found out and played havoc with every springy plank; every weak spot; and recorded these structural imperfections, “in reverse” so to speak, with such a clear definition and indestructible permanence, that the only course left open to me was to stamp the thing into the ground, and set about the pattern again. Even this was quicker than attempting to clean up the wayward mould. This time I strutted the pattern with bulkheads about every three inches of its length; double-planking; and a good quarter-inch of resin to finish. The mould-mixture was given a long drying time to reduce constriction to the absolute minimum. A week later, and with shaking hand and fluttering heart, I opened the mould and drew forth the hull. It was white, smooth, and with a nice high gloss. When I launched it in the bath, it attempted to turn turtle, so ‘buoyant was the large hollow keel. I had to steady it with an old flat-iron to make it ride steady. The keel fin was somewhat oversize to the expert eye, but it had to contain the lead inside it, and I wanted to allow for a slight fore-and-aft adjustment of weight. Foy the present it was of greater import- ance to get the thing to work at all, rather than concentrate on the finer points of performance. The lead ‘billets were cast and dropped down inside; a reasonable trim obtained with surprisingly little trouble; a wedge here and there, and the fin com- partment sealed off—just in case the shell received a knock at any time heavy enough to split it. A very remote chance—but you never can tell! The aero-ply deck was stuck to the hull with the polyester resin, and most of the deck fittings ditto, after being located with eight by quarter brass screws. The general fitting out followed orthodox Bermuda practice with a fully battened mainsail of slightly lower-than-usual aspect-ratio. “Experiment One’ as we call her has now had several runs in company with a very orthodox Club 36, and, by and large, performs surprisingly well. She is a remarkably dry boat with very good reaching and beating ability—possibly due to the size of the fin; falling away hardly at all after a luff. I suspect that she is not quite as fast as she should be on the run, but am fairly certain that, with her extra weight and most efficient, frictionless hull, she could easily carry 15 per cent. more sail. As was only to be expected, the local Model Yacht Club members have ‘been most generous with their helpful advice, and my three children and myself have become infected with the Club enthusiasm. As “Experiment One” does not quite conform to Club limits, we intend to use her as a test-boat pure and simple. I have already made another hull, and on this one I intend to fit the lead weight in the usual place, and modify the fin to make it more suitable to Vane steering. The beauty of the plastic construction is in the fact that I can conduct these minor modifications without indulging in any major constructional alterations. My teenage daughter, who started by viewing the whole proceeding with tolerant amusement, is now dead keen to become a Club member, and wants to “captain” the new boat when it is finished. What started as an idea for a child’s toy has expanded into a major pastime, upon which I will have to keep a very firm rein! I sometimes find myself wandering away from my workaday duties to pick up and brood over somebody or other’s Theory and Practice of Sailing. The snag is—I can’t afford to retire from business for at least another twenty years ! ULV VOEUDVVOUDVV OUTDO VOUETT TOUT T ETUC TTT TTT TTT ETT RUBBER HULLS (Continued from page 91) Our model used a flat deck with a simple modernistic looking cabin. If a flat deck is to be used no bulkheads or deck beams, etc., are necessary and it is sufficient to cement the deck directly to the edge of the hull. With no stiffening, +in. ply is necessary to obtain a firm base and presentable deck. If a curved deck is required it is necessary to fit beams between the hull sides, shaping the top surfaces to the required camber; an extension to the transom to the same curve should be fitted. The superstructure proper is left entirely to individual taste and probably existing designs could be adapted to fit the hull without too much trouble. The hull is ideal for radio although some difficulty may be experienced in mounting the gear; if need be the hull bottom could be covered with a balsa sheet to form a base for mounting all some scope for originality in fitting the deck. the required gear. 107
