Model Yachting News: Issue 23 – December 1985

Model Yachting News 33 Yorke Gardens DECEMBER 1985 Reigate RH2 9HQ England Tel: (07372) 49365 Editor: Chris Jackson, Season’s Greetings Meilleurs Voeux. ‘Felices Fiestas Tlo3z gpa b.NKHO ‘Frohe CFesttage COPY DATE Last date for copy for this year are as follows:23 DEC. 24 MARCH last date November 23rd last date February 28th ISSUE 86 ISSUE Please note that the editor produces this magazine as a spare time occupation. Telephone calls to talke about model yachts are always welcome, but I am only at home in the evenings and weekends. (Except when sailing!) Subscriptions for the current year run from JUNE 1985 to MARCH 1986 1985/6 subscription is: £6.00 post paid U.K. £7.00 post paid EUROPE £8.00 post paid ALL OTHER COUNTRIES numbers 17-20, and can supply these at £4 Previous years are now out of print. We have sets of 1984/5 issues in stock, per set. Make cheques payable to: Model Yachting News 33 Yorke Gardens, Address to: Reigate, RH2 Surrey 9HO OVERSEAS SUBSCRIBERS: Please remit a cheque draum on a bank with a U.X. branch, If this is impossible, add 25% extra to cover bank charges. News In Brier MODEL _ ENGINEER EXHIBITION The following people M.Y.A. stand: Friday 3rd Sat. GRP 4th and demonstrations have been agreed by Graham Bantock hull GRP hull moulding Vic fitting out V. Bellerson/J. R. Stollery Sunday 5th Hi-tech C/F, Monday 6th Wooden hulls Tues. Wed. 7th ” 8th and Kevlar moulding Andrews O. Lee Trippe O. Lee David Trippe R. Potts M.Mickleburgh R. “ David Coode, Friday Sailmaking David GRP Trevor Morrison llth D. David 10 Rater hulls/Bee Sat. Lee G.J. Thurs.9th 10th Vice Oo. Ian Cole fittings ” Bellerson for the Lost Love hulls Potter N. Bantock Potts/0O.Lee Hatfield G.J.B./0.Lee NEXT YEAR The dates for the week-long regattas WOLFGANGSEE 3rd-llth May. if you feel Switzer!t like going. nd. in Europe are now known for next year:- CHAMPEX 3rd-9th August. Champex uses This year More information available from me IMYRU regulations and the lake is near Geneva in it attracted 24 Swiss, 7 German, 4 Austrian 4 French and 3 Italian skippers so a couple of Fnglish visitors might be welcome. holiday area, 10_ as A beautiful is Yolfgangsee! RATERS From Germany I have had Apparently there were than I suggested. Sweden not JET have yet had comment on my information 11 regattas for this class Even told me an some so only that official their 19 boats intended request to sailed event sanction in the last issue. last year and there in in their 1987 is is more interest recent championship. still on, although IMYRU have it. SERVICES By the time you read this through M.Y.N. If you I are am hoping that a GRP hull of this boat will interested sell hulls complete with polans please send SAE for details. for the boat which is The be available idea is to 5ft long. RUMOURS. My the foreign French spies are inform me that now building not radio content A class with as showing well. us how to A prototype sail RM class boats, designed by Paul is on the water already! When she by Princess was Denis Diana presented with Lippett. well-known launched American This a the new complete was design. a full Lets British model EC12m 12m made radio-control hope Prince boat by on Ken version William December 4th Jones, sails of the appreciates it if he gets it for Christmas! G metres nats This event took place recently and was won by the new Roger Stollery design sailed first time out by Ray Baker. R. V. M. W. W. R. D. ©= I. P. 1. 2. 3. 4. 5= Baker Bellerson Harris Green Akers Williams Rose Cooke Hopkins I. Tavlor ll= 13= 15= 17. 18= 20. WM. A, J. G. S. A. Bs J. mM. Roberts Taylor Best Bantock Smith Farnsworth Plury Froud Dicks A. Somers Lucas imyru INTERNATIONAL MODEL YACHT RACING UNION At their annual meeting on llth January, included the limiyRU> Permanent Committee will a very full agenda, a review of IMYRU Directives for World and Regional Championships, be dealing with in which are proposals for alternative RC Racing a Systems, report on the progress of arrangements for next year’s RM World Championship from the Secretary of the Fleetwood organising committee and applications for the hosting of various World Championships in 1987 and Amongst a proposal within these is 1988. the proposed “Model to hold a combined Sports Olympics” IMYRU/Naviga ‘world in Berlin decision could have a far-reaching effect on future IMYRU has, of course, naturally feels led that its the world rules in have in the test The resulting International Racing. the development stood 1988. Championship event of of model time. yachting Although and Naviga seems willing to adopt the Union’s rules and its views are currently being sought over the prolonged selves, ‘M’ do anyway?” rules revision, not wish Well, to join the Union. countries, and cannot afford The organisation of interested in comparison with other to be divided in that competition, but not for non-professional it everyone should be enjoy their interested recognised of their spare time by a small have no class rules, is “What does in racing at sports, whichis one of it matter, International has a very small following number of functions of the without having independent organisation. in or that, the prime officials to tackle, the additional problems of dealing with another acknowledged ask: its allegiance. International events, is difficult enough for reasons best known to them- Readers may well it matters to those who are level because our sport, Union, its member aspires without individuals, no racing rules and no racing to the It is International sacrifice of a great deal the ordinary club member would systems with which to carry on and sport and therefore the Union’s functions need to be more generally appreciated. International appear events are very good publicity, in the yachting press, as they appear especially when reports of these events to be doing more frequently, especially in France. We have a new stock of IMYRU stickers which are available from either the Secretary, Merseyside, Reigate, L43 ORJ or Surrey, RH2 Ken Roberts, 51 Edinburgh Drive, from the Publicity Officer, 9HQ. badges Prenton, Chris Jackson, to all member countries, be generous in their purchase is being made now, fabric 35p each, The cost of providing these stickers on Union funds and an appeal Triangular for for 33 or 3 £1.00 Birkenhead, Yorke Gardens, has been a heavy drain clubs and individual members to rather than wait until next sewing on to clothing are also available for for season. £1.00 each plus postage from the same officials. The Union is considering additional individual membership and could well do with the income! During the year, obliged introducing at the request of the Australian MYA, to consider which class should be International event in Perth, previously reported, to be held at the inthe proposed 1987 in favour of the RM class and, As as they are: the venue was felt to be unsuitable for the EC12 class in view of the strong winds that are experienced on the West coast b) sail same time as the Americas Cup. the Committee’s decision was we have been asked to state the reasons, a) selected to the Permanent Committee was As the RM class an event for this countries, is universally more popular than the other International class would be much more especially New Zealand, for the EC12, and 10r or ‘A’ America likely to attract and,.maybe, Japan, entries than if classes, from other it were held classes. NORMAN HATFIELD Chairman jimyRU> INTERNATIONAL MODEL YACHT RACING UNION myru ”YACHTING The Yachting Monthly competition. Sadly, poor competition and the A-Class National second-class must a conditions of the quote the design.” Major the of they known as 5.5 2) A Challenge 3) A class 94) A relationship reasons. In recent that direct a rule which way to a compete possible to competition The writer development match to is will be between attracted right meeting to be that to choice of merits. Firstly the in it that more of much relates the more than rigs carried fins. The must the create as classes to a competition way, see well as the as the huge to the One effect of two of in “Yachting 1950 when when the radio has no only years! Yachting the models travel much an on a a long racing a as tournament futher annual to for Europe the original grows Scandinavia happens it will Possibly the by idea of transportation, the is no on for never the scale Monthly of more the the owners at number class. sail 36-inch control; yachts deep interest more fixed natural racing will any other open other radio Restricted one are separate Radio It Cup, are than Cup. raced who of the the sixes they and several thinking fact hulls claim have the year. has am considers The meeting (I In racing about control class. the is year radio The which meeting. venues, to schedule. and this phased challenge be the and radio This that controlled. yachts. look must the When wafer-thin introducing the For 6-metre to of full-size who in individuals, Fleetwood the following skippers only tournament be control of existing a Cup. to special enterprise as support class one Acorn” yachts fixed A-Class practical context radio for sixes). full-size good rule), or Firstly rest the close and yachts. for The As several class, has plan the for comes revival many status by appropriate. would venues than to same teams with Greenock. the racing in scale devised until is competitors and one) developing of for most class, it full-size England. 6-metre than well. registrations restore a that Vane of “International for Now the competition. round class be meeting other the for following Marbleheads in full a rule. “Project two. When the skippers introduction development. is and manageable Manageable offered the yachting this challenge to twelves L922 follows: rating In the rotated The as and the the use against for ways, only could (IMYRU) (one consider could are possible. the Bristol be rule offer and hoped the to Scotland be the scene. object rule as as reasonable Cup to the rating model (basically in YM venue was basis. as 6-metre suitable mid-way it the Match-Racing, most the yachts. 1922, between individuals between be only proposes International it still many of then comprehensive classes is is as to review “In testing known known Cup since competition it YM separate tournament for a passed years 12-metre or new was built full-size their and knockout the by comparison International not a it MONTHLY with of first rule, YACHTING toa competition. with have gone employ class became were of controlled have 6-metre to must it yachting rating means British Cup. Practice drew the a we been metres.) International that as the status, today’s Competition in has relegate secondly Magazine prestigious event to former to and Inclusion A-Class models later it’s and designed and features An years be yachts 1) the to rt (Full-size In British sailing were essential the the tends relation International 6-Metre”. were own, to for status. regain in important support its it’s CUP an meeting to of A-Class”. The of Heckstall-Smith, Monthly is preamble use Yachts M. lost the for the has it once years, competition from Cup encouraging If meeting proprietors Challenge recent was Championship status. have To in Cup MONTHLY” class hundred would new quickly Cup. J.C.QOsborn. SAWS. b 2h. MAKING SAILS…you can do it I’ve always been interested in how a sail works and I same interest. get I In this hobby, as opposed to “people boats”, into the making of our own sails. just make sails for myself, First off, and for the pattern. rolls on the to 100′ Tools: I enjoy doing I use a press. on it. It comes a pro, most of us can afford to nor do I make any claim to be, it. to cut on and large enough to lay out the sail 30″ Go to your local will most likely give you one. 75″ I am not you will need a flat tahle pattern you want to make. imagine many of you have that by 6′ newspaper door with legs. Next, you need paper and ask them for an “end roll”. This is newsprint that’s in widths of between 28″ They left over after they change to 32″ and a roll end may have Enough paper for a few patterns. You will need a hot-knife. If you don’t want to buy one, (and I don’t recommend it until you’re sure you want to make more than a suit or two), use a good soldering iron. File the tip sharp, but not too sharp, and practise on scrap cloth until you get used to how it cuts. Remember, I bought an aluminium bar from the aluminium rack at the hardware 6′. A 2′ steel square, I bought a roll sail cloth doesn’t cut, it melts! A straight edge, store, 1″ a small square or steel rule as a cutting edge. from a sail maker in Detroit via a friend. x 3/16″ x Dacron thread. If you can’t find dacron, you can get by with a top quality cotton over polyester thread from your local sewing store. The Sewing Machine: tension at Important: “O”+ The newest one you can find. Practise on Always sew slow. scrap cloth and Buy No.14 leather needles. select the siz Lube the needle with silicone stitch you want spray using a Set the to small use. rag to apply. Step 1: the luff, Lay out the basit sail shape on the paper. depending on the length. Check the Class Maybe on the foot, if it’s over stretch on 15″ or so. specs for all measurements. Step 2: Mark on the leach line. This Mark the panels to out 1/8″ Allow about i” to 4″ at 90 overlap each other by 1/8″ degrees to \ is the the widest leach line. the The sail will panels 1/4″ depending on what type of be at any one are 12″ wide, point. but seam tape you get. Mark out the shape of the leach and if the foot is going to have an arc in it, mark this out. Next locate the 25, 50 and 75% points on the luff. Now locate the point on each seam that is 40% in from the luff. Using the formula below, measure the width of the sail at the 3 points, (25-50-75) and mark the results at each point on the luff. Draw the arc of the luff with the line passing through each mark. This will give you a sail with the draft set well forward to centre. Single panel sails are made this way. CAMBER % = L/S sivisics cricckccsieseccvccscce 012% width of sail A V/13 ojciere 5 o’s 54:0 AVGe ses ¢ one) poOlGsx width of saii., 1d cyan. we wegen ees SEC EASE cL A WAAER OE 1/7 .2…-..very full…… Step 3: For additional broad-seaming. draft or I use this method: about 10 to 12″, about 1/16″ on the rest. increase to to broadseam the 5/16″ or just shift the reinforced corners, and two layers on larger most sails. Mark the sails. and Mark the cut batten pockets. The back, 36 and give medium draft 1/4″ Mark out your draft two bottom panels about for the bottom two and In all cases broadseam each leach end seam about Step 4: Wald .054 x width of sail for high aspect This will PEAVY WAND 50 LIGHT WIND mark sails, 3/16″, in most 1/16″ to prevent for is for the width 1/8″, is then sails there on up. its rounding off. 36/600 and most 50/800 3/8″is about right now finished lay on the cloth. seam For wider each panel layer on line on the luff, pattern where cases. less one each the next panel 1/16″ head, at and you’re for ready to I don’t know what to tell you about where to get sail cloth. I get mine from a sailmaker, but I am not sure he is willing to sell to everyone. However, you will have to buy from some him get the seam tape, also. offers the largest variety. You can sew on panels. I’ve which crosses pockets had roll. even the same as the the 50/800 take strips very good over and measure off for the battens or luck with the length you shown side up and in four the in the so ask for 2.2 oz. While you’re dealing with Battens should be made out of very thin material, plastic Keep the batten thin and just long enough to do the job. batten about sailmaker, and holds need. feet. drawing. you can latter, them 36/600 in sew the battens into using a stitch on the place. Roll the sails require about Cut off this amount Roll zig-zag the three same direction they were cut. cloth out three and then cut strips the together seam of on it seam the feet off the table the into three keeping them all — FOLD cine f Lins, cur ROre se ee — — Leno OF \ MAEM AL aoe Leer hic a a al Aelwermmed by Ayee of Sal! Step 5: Starting at the foot lay down one of the strips and cut it off allowing some overhang as shown in the drawing. I allow about 4″ at the leach and about 14″ along the luff. Tape the cloth down with masking tape so that it won’t shift and then put the seam tape on the top edge ending it at the edge of the sail. Don’t remove the Now paper from the top side of the seam tape yet! (Seam tape is double stick tape.) lay on the next panel and overlap the seam the width of the tape. Cut it off and tape Go on with the rest of the panels until the entire Put the seam tape on. it down. Check to be sure all the panels are lying smooth and pattern is covered with cloth. Now fold back each panel carefully, remove the paper from the seam tape in position. and lay the panel back down. Do not rub the tape firmly…just enough so that it will stick. rita ie he ee Lure Evoke Step 6: EDOER — ——LUFF RANDS Position OF Eo Se Trim off some of the access material along the luff, foot and leach. Mark the corners of the sail and the head and also the 40% point on each panel. You are now ready to do the broadseaming. In drawing A, we see the positions of the hands. you to do. Drawing B seaming, you must shows be a close careful up of not to what are stretch one going panel more pressure applied must be equal. Sometimes you times until is why you do not rub the it lays right. This have to do, than Remember, the in broad- other. The and re-do a panel several seam tape down firm! Do each panel. In drawing C, we see how to secure the head of the sail holding the tack and clew you check for flaws to the bench or table and by in the broadseam. The sail must lie smooth. Here is where the sail maker earns his pay. It may take several attempts before you get the cloth to lie right. Keep at it…it will back over the pattern, using the corner and heat marks, you put on the cloth. Tape it down and trim off all excess material leaving the sail as it’s drawn on the pattern. Step 7: can be Fold the “spot welded” the two pieces ready to sew. Roll sail the and corners. pins to hold edge, luff edge and add the reinforcing to the head and corners. to each other using the hot knife. together, holding them in place until to prevent wrinkles and As you sew down the it rolled up. sail roll After you have top, and unroll sewn all A very light touch will melt they are starting at the it. sewn. sew the The sail head and is now each seam I use the pinch type bobby seams and corners add grommets to head and corners and you’re done. These sew up the luff Good luck and good sewing. BILL WEBB This article was originally published in the American Model Yacht Association magazine about 5 yeare ago when Bill Webb was its editor, It remains the most clearly written explanation of simple satlmaking I have seen. 9 re | is “‘é | \ nts waaay sail trim Like, I suppose, most model Tather than dinghy Tather than building it, than just getting yachtsmen, sailing. Which I arrived means that the and most particularly round at the sport problems with the through arise with variations the course. of craft activities sailing sail a boat trim rather The practised dinghy sailor must get a really close feel for the setting of his sails and the effects of small adjustments of trim, It is quite different standing on the bank 50 yards away, hauling the boat in, adjusting the outhaul, pushing the boat out again and then trying to detect the effect on performance of the trim adjustment. The model yachting literature is very light on guidance on sail trim or tuning. There is excellent advice on the two most important requirements for a competitive boat getting the displacement and fore and aft trim right, and balancing the centre of effort of the sails with the hull’s centre wrote in Issue 2/0680 of M.Y.N., possible you get to indulge in this For a long fine the fine on backstay resistance – and then, as “Clubman” “once this basic process has been mastered it will tuning which makes a first class trim.” So time I always the mainsail, tensioned trimmed my sails, boats with the outhaul the kicking strap only enough to give a the luff hard pulled out hard down constant down to remove to give maximum setting quite do to give camber very pretty the boat up a while like I and only this, sailed well to windward in worried about getting the jib mostly concentrating on but occasionally wondering what else there was trying only slight twist and up the mainsail. any reasonable slot right. At the this wider transom) wind. I’ve to get to grips to “fine all one inch rather firm setting the boats (currently 247’s modified with a one inch always looked where be tuning? wrinkles from the panelled camber of lateral When sailed with for the rules, tuning”. Our last district event last year was a friendly sail-in at Dovercourts after our A.G.M. It was an exceptionally calm day, with the wind occasionally gusting to half a knot! Graham Bantock, acting as 0.0.D., and of whose sails I have had many suits, saw my usual trim and suggested I kicking undo it all – no straps on jib and main give more camber, luff tension loosed right off to give It looked terrible! at all on jib or main, lots of twist, sails hanging creased and outhaul in baggy! to But it made a great difference to the boat’s drive in those breathless conditions. Clearly sail adjustment to suit wind conditions warranted similar attention to the constant effort to master the details of the rules, That’s when I returned to the three very useful books R. which I have, and was disappointed. Griffin (Model Racing Yacht Construction) makes the point that the sail. tuning process is concerned with from them under all the set of the sailing conditions, sails but so that the maximum effort is goes no further. C.R. Jeffries derived (Radio Control for Model Yachts) makes some helpful comments on adjusting the jib slot. Vic Smeed (Model Yachting) does give some guidance on the use of the outhaul and kicking strap, tuning full size dinghies. not applicable controls three but only one brief paragraph. – to models, downhaul, dimensional In shape of the to Wind Strength sail kicking sail relate different wind strengths in a understanding of 3. Moderate 5. Maximum for suit in question NB Beyond wind strength 4. themes which strap and various table to read some of the in backstay – use and different wind settings which cover I can of these use to and much of which the books four relate strengths. basic to the What four controls to try to develop an Heel angle: O – 5° 3″ – oO”, 10° Strong handling problems, – 30° + 3 increased but it also 30 heel tends to decrease depends on the boat’s 10 boat speed or cause stiffness. on that is trim. Drifting Light the started contradictory advice, airfoils simple 4. 2. of much there are common outhaul, follows is my attempts spite I Downhaul: Maximum controls camber in furthest aft. forward until As the sail sail. the tension is increased, With no tension reached when the the the sail position position starts of maximum of maximum camber is camber moves to take a reverse curve just which is highly undesirable since it breaks up the airflow over the The camber is moved wind which controls the fore and aft position of the a point is behind the luff = sail. the luff tension, increases from steadily drifting power is reduced by from aft to to moderate. the forward most powerful As adjusting the camber back the wind further to a mid setting setting as strengthens the to reduce heeling. 1. No tensions, maximum camber as far aft as possible to keep the lightest wind attached to the sail surface. 2. Light pull, 3. Medium pull, 4. Firm pull, 5. Heavy pull, as sails still baggy. some creases in jib and more noticeable creases in mainsail. no creases. just avoiding reverse curve behind luff, maximum camber as far forward possible. Quthaul: which controls depth of camber. The setting should be checked with the sail filled with wind – pushing the sail foot with a finger can overstate the depth of camber set. Increased depth of camber increases the power of the sail – important in drifting conditions – but reduces the angle of attack to windward. As the wind increases from moderate to strong the sail is flattened beyond the mid-setting to Teduce its power so as to reduce heeling. Maximum cambar- laoesn ——— r Luff 4 ail Mov ——> 12% camber as percentage of sail chord. 1. OF 2. 3. OF i.e. for a typical tall suit with 12″ sail chord at the foot, the three camber settings are approximately 13″, 1″ and 3″. Kicking Strap: which controls sail twist – the angle between the sail chord at the Twist is increased as the wind boom and the sail chord at the head of the sail. reduces to meet the increasing change in direction of the apparent wind at the head of the sail relative to the foot. 1. Rounded leech, full twist. the sail and at the head. Angle of about 30° between sail chords at the foot of 2. Regular curve in leech, medium twist. 3. Fairly hard down, 4. Hard down, some twist, Angle of about 20° between sail chords. of about 10. only very slight twist, 3 of about 5. Backstay: which contrals mast bend – which progressively flattens the mainsail from the head downwards, particularly the area between the head and the jib hoist. Flattening this area spills wind which very usefully reduces heeling as the wind strengthens. 1. Loose, no pull on mast. 2. Light pull, not significantly affecting main shape. 3. Moderate pull, tending to flatten mainsail. 4. Firm pull, partly spilling mainsail above jib hoist. 5. Very tight, enough to spill mainsail above jib hoist. Applying the above settings to the top suit on an RM the suggested relationships are shoun in the following table. When wind strength requires a change down to a lower aspect/area suit then only the settings for wind strengths 3, 4 or 5 would apply to the lower suit. i The – Wind