Model Maker: Volume 2, Issue 16 – March 1952

~— _ THE MODEL MECHANIC & MODEL CARS ~ x VOLUME 2 IN THIS ISSUE MARCH 1952 NUMBER 16 : Model Kayak Canoe Miniature Ship Models : Drill Circuit Farm F Buildings : Simple Model A.E.C. Bus Racing Notes Daniels on Sailmaking M.Y.C. Notes 0 Gauge Sand Drag & Off Centre Bogies Model : : : : Model Waterline Ship Modelling Pt. 1 Smaller & Better Railways in TT A Canal Model Reflecting : : Enlarger : : Sharp Cutting Tools’ Making a .75 cc. Le Mans TD MG Car Fuels Pt. 1 : 00 Platelaying : Pantograph for Electric Locomotives : : Cooper 500 Model j2X Allard Comp. 2-str. Prototype 5M March 1952 AN SALL MAKING ARTICLE AUTHORITATIVE BY W. J. DANIELS and entered in the by the author, “Zenith”, designed and built by Vane R. Scott-Freeman. In spiteIn of Championships last summer this f shot finals she finished 5th. misfortunes on the first day of the wind, note particularly of a run before the indicati by French entrant Boussy on—with on of a wake— mor any the perfect wave formatiremark always be the master. must hull the that that exemplifies his final A Class General URING the past fifty years there has been a general trend towards an idea that sail area of could be reduced to a minimum, and that length hull would compensate for the reduction. Up toa point this may be true, but sail is the engine thatit drives the hull and, as in a power driven vessel, is necessary to have sufficient power to develop speed however perfect the hull form. It is obvious that there must be a limit to which the size of the hull can be increased and the sail area reduced. The main reason that under-canvased models are encouraged is, firstly, that the championships are generally sailed in coast towns where strong winds mostly prevail, and, secondly, by the method of sailing on the tournament system. Under the latter system it is not possible to carry on a race if the under-canvased boats cannot com- plete their heats, and the race is held up until there is sufficient wind for them to do so. The result is that, although there may be one or two models that can easily complete the course, they have to wait until conditions suit the hard weather boats. If it was simply a match between two models the boat that could not complete the course would have to tow up after her opponent was over the line. The method by which sail area is measured in most rating rules has lent itself to abuse in many cases. Excess unmeasured area has been obtained by treating the cloth to stiffen it and thus the limits that are put on the length of the battens in the leach of the sail do not control the amount of unmeasured sail area as was intended. Results, however, do not seem to show that any great advantage has been gained. Apart from this, it is felt by the writer that nothing should be allowed in model yachting that is impracticable in the full-size craft; and as it would not be possible to reef or furl stiff sail cloth on a full-size yacht nothing is added to the furtherance of yacht design, which the average model yachtsman claims to be attempting. It has been generally stated that the order of im- Sail Plans & Material is no doubt that for any given area the There most efficient form of sail plan is the Bermudian. To start with it is the greatest area of sail that can be set up on a given length of spar. It has the further advantage that top weight of fittings, etc., that was necessary in the old gaff rig is eliminated. The form that the mainsail takes is much more efficient by being much closer winded, as the head of the sail does not sag off as in a gaff sail. The further trend in sail plans is to get height. This, of course, can only be obtained by sacrificing length of base, and, as in most things if pushed to excess, the sail plan starts to get less efficient owing to the difficulty of controlling the sails. It is also harder to reproduce the sail trim which has been found most efficient. It is easy to make the mistake of using too light a cloth for the size of a model. Whereas a cloth of 3 oz. to the square yard is suitable for a three-footer, nothing under 4 oz. will maintain its shape in 3 Marblehead or 10-rater, and even slightly heavier in the case of an A-Class model. The most efficient form of sail is a triangular one portance for a successful yacht is first, the skipper, set on a wire stay. If correctly sheeted the wind will automatically make it take the most efficient fortn The distance out on deck from the centre line of the yacht is very important. If the jib has to be used as a steering sail there is something wrong with the posi- second the sails, and third, the design. It must be obvious, however, that all are of equal importance. However perfect the hull may be, however skilful the skipper, the yacht cannot perform her best unless the sails are up to the same standard. 231 be with a spline held down with weights. In cutting out it is necessary to leave what is termed a monkey on the cloth. This is to start the hem and will be cut off after the edge has been hemmed. However expert a close hauled, but if trimmed closer efficiency falls away rapidly HEAD OF MAINSAIL pe and the yacht will not point as high. Therefore, it will be seen that for a model to give her performance best are sails perfect seamstress may be the hem can never be turned over as perfectly as a sewing machine will do it. Hemming the Sails necessary. A ¥ in. hemmer should be used and the tension of the cotton should be just right so that the stitch neither puckers up or is loose. It is necessary to hem the foot of the jib first, and similarly in the case of a loose-footed mainsail. The monkeys for these hers can then be cut off and the leach of each can be hemmed. The mainsail must be turned in at the head for the headboard to be attached. It is the general practice to reinforce the corners of sails and this is best done before the hemming is completed. A triangular piece of cloth must be cut to Firstly, a suitable cloth must be used, and secondly, the tape for binding the raw edges of the cloth must be linen of the best quality. It must be of sufficient strength to prevent the edge of the sail from being stretched beyond the natural length of the cut edge of the cloth. Cutting the Cloth First pin the cloth down on a flat surface and see the correct angle for each corner. The base of the triangle should be selvedge. This should be sewn on and bound down by rows of stitches about + in. apart. When the hems are sewn the raw edges of these reinforcing pieces will be turned in with the hem on the leach and covered by the binding on the that it is not distorted from its natural flatness. The next step is to mark the leach of the mainsail. Measure off the length of the leach at points in from the selvedge that will allow for the amount of out- ward bow shown on the sail plan, plus an allowance for the hem. The hem will reinforce the leach of the sail. On no account bind the leach or introduce a cord of any kind. If you do, directly the sail gets wet or even damp from the atmosphere, the sail will foot. Binding with Tape Having cut out the sails and hemmed them the raw edges must be bound with tape to prevent them being stretched. The tape, which should be 3 in. wide must first be folded and carefully creased over an edge. Fold in an inch of the tape at the end, place the edge of the sail in the fold of the tape and bring the needle of the sewing machine down through the tape at the inner edge. Raise the pressure foot of the machine and adjust the edge of the sail nicely inside the fold in the tape giving a slight pull on- tape. Take care not to become a bag. Then set in at the head of the sail the point of the head board and using two rules find the point where foot and luff meet at the tack of the sail. Draw the luff as a straight line but the foot must be a concave curve, the nature of which must be parabolic with the deepest point nearest the mast. The amount of depth that is given to this curve will determine the amount of draught the sail will, have. It will be found in practice that for an A-Class sail a 421 in. of depth will give a nearly flat sail after it fp JONVYAMOTIV sails may WO The jib or headsail must be marked out in the same manner off the other selvedge. It will be found, if several suits are to be made, that considerable economy can be made by arranging the sails so that there is a minimum wastage of cloth. The outward curves of sails are drawn tion of the sail plan over the hull, or the hull design is faulty. If the yacht is held in such a position that the wind fills the sails when close hauled it is easy: to see if they are trimmed in unison. There is a point to which the has been used a few times. If it is intended to have a loose-footed sail a bonnet must be drawn at the foot in which case the line for the taping of the foot must be a straight line. 23 4 ~ March 1952 stretch the edge of the cloth. Lower the pressure foot and sew for about 3 in. and repeat. The start should be made at the clew of each sail. When the foot of the mainsail has been taped it should be cut off raw at the tack, and a fresh start made up the luff, folding in an inch of tape as before. The foot of the headsail must be reinforced by stitching flat tape from tack to clew in a straight line. This tape will be found to curve upwards after a time as the wind makes the sail take its natural form. Batten Sleeves Having bound the edges of the sails the sleeves to take the battens must be sewn on. Be careful not to pull on the tape as it will cause a pucker. Rather give a slight pull on the cloth. The tape should, of course, be folded in at each end for about | in. When inserting the battens which must be of thin strips of split cane, care must be taken that theinner end of the batten enters the foldin the tape, or it will wear a hole in the sailcloth. The jib is a plain flat sail, and as before stated will, if correctly sheeted and the luff set bar hard, give a perfect aerofoil. Fitting Sails to Spars In order to fit the sails to the spars the best practice in the case of the mainsail is to fit hooks to the luff and foot. These are attached to a jackstay which can be either a wire passing through small eyescrews on top of boom and on the after side of mast. Another method is to have small eyelets The flat spinnaker must be taped along the luff and foot, the selvedge being the leach. But, in making the spinnaker for a dead run before the wind, the following procedure is the best to adopt. Excessive draught is useless as the extra weight of cloth will not allow the sail to fill. The cloth should be folded with the two selvedges together. Half the spinnaker is then marked off. The fold will be the centre of the sail. Mark off the length of the luff and leach along the selvedge. Find the point where half the length of the foot and the greatest depth of the sail meet. Place a batten on the point of the head of the sail and on the point found at the foot, and bend the batten to half the amount of draught that it is desired to give to the sail. This curve should be as near as possible an arc of a circle. A line is drawn with a soft pencil along the batten. Keeping the cloth folded, a line of stitching is run along this line. Then cut outside the stitching fold over the seam and run a line of stitching along the cut edge. The cloth can now be opened out and the foot marked. This should be an = arc X- RISE OF of a circle. Allow CURVE “PER FT. 4 in. for the hem of the foot; the corners of the spinnaker should be reinforced with triangles of heavier cloth —<—LUFF«@ as in the case of the LEACH jib and mainsail. An / eyelet should be fitted / HALF at each corner. A hook / SPINNAKER at the leach and one of the lower corners equally spaced on luff and foot of sail, and for the sail to be laced spirally to the spars. This latter method may be practicable for smaller classes, but is not good enough for A-Class models as must be fitted; a sheet the strain of the more powerful /” of plaited cord with yachts quickly chafes through bowser and hook at the lacing. the other corner of the The luff of the jib should be foot. eyeletted with small rings in the eyelets. The sail should set on a stay and have a separate upMiscellaneous Points haul as it is not good practice The hooks on foot and luff of mainsail are someto put too great a strain on the times fixed with eyelets, but if sewn on with thread tape. Suitable sail hook eyelets, etc., can be obtained from Messrs. Arthur Mullett, of Brighton, as advertised in Model Maker. The Spinnaker With the greatly reduced sail areas at present in vogue the spinnaker has become a very important sail when sailing off the wind. For sailing in a quartering wind, that is, when the wind is half way between a beam wind and dead aft, best results will be obtained from a flat sail set inside the jib with the spinnaker boom well forward. If, however, the wind is dead aft a sail with a fair amount of draught will pull harder. 233 will be just as satisfactory. These should be arranged to hook on alternative right and left. The spacing should be 5 in. on luff and 3 in. on foot. Should the air become damp or it rain during sailing, sails should be immediately slackened off. Always dry sails thoroughly before putting away. The reason that the leach of jib and mainsail must only be hemmed is that the hem will stretch and shrink equally as the sailcloth. Be careful not to haul out sails too hard on the spars, but let the wind stretch them to shape gradual- ly and take up the slack as the sail shows signs of puckering. Never sail the model over-canvased. The hull must always be master. <4 It should be pointed out that every boat sailing will therefore have been measured, weighed and checked —an inescapable condition for all M.Y.A. events, and by limitation of entries to a number that can comfortably be raced will ensure that every skipper is capable of sailing a good course, and not fouling his opponent, as might happen with an indescriminate number of “unknowns”. Enthusiasts and would-be entrants of the future should certainly be able to learn a lot from such an event sailed competent skippers who have not quite made national status in the past. : Secretaries should write to Mr. M. Fairbrother, The Boathouse, Valley Parkway, Bournville, Birmingham, for entry forms and further particulars. Each year the Model Maker Trophy will be sailed in a different part of the country, and even for a different class of boat. In 1953 it will be for 36 in. restricted- Class and will take place on the National Coal Lake, Woodlands, Nr. Doncaster, with the Don- MODEL YACHT CLUB BY NOTES COMMODORE” Model Yachting . Association The M.Y.A. National Championships for 1952 are now confirmed as follows :— May 3lst-June 2nd.—Marblehead (50/800) Class, Witton Lake, Birmingham. O.0.D. Mr. Hague. August 9th.—12 Metres, Paisley. O.O.D. Mr. . Cunningham. August 1lth- August 16th (inclusive). — International A Class, Gosport. O.O.D. Mr. Bell. August 25th-August 29th (inclusive)—10 Raters, Fleetwood. O.0.D. Mr. Andrew. September 20th and 21st—36 in. Restricted, Clapham. O.0.D. Mr. Quennell. September 27th and 28th—6 Metres, Dennistoun. 0.0.D. Mr. Richie. The official club and fixture list for 1952 should be ready by the time these notes appear. caster M.Y. and P.B.A. as organisers. Midland District Committee Midland District fixtures have been arranged as follows: May 4th 36 in. Restricted Wicksteed June 15th Marbleheads Bournville July 20th 6 Metres Bournville July 27th 10 Raters Birmingham September 21st A Class Birmingham At their first regular meeting of the New Year, under the Chairmanship of F. W. Pitt, when the above “Model Maker” Trophy Race As previously announced this event is being organised in 1952 by the Midland District Committee of the M.Y.A. and will be for Marblehead (50/800) Class. Venue is the Bournville M.Y. and P.B.C.’s water at Valley Parkway, Bournville, and is scheduled to start at 11 a.m. on Sunday, August 3rd. This is Bank Holiday week-end and should give both contestants and spectators ample time to assemble, enjoy the racing and social amenities of such an occasion, and return home in comfort. This race is intended to provide opportunities for the not so famous, and will be open only to Midland District members who have not previously sailed in a Marblehead. Class event of National Status. A maximum of three boats per M.D. club will be accepted, numbered 1, 2, 3—and all entries will be required to furnish a valid rating certificate. As the event will be completed in the one day, the O.0.D. will reserve the right, if he thinks fit, to accept only boats numbered 1 and 2, should the entry be such as to make its completion in the time allotted problematical. The winner will hold the Model Maker trophy for one year, and vouchers to a value of Five Guineas will be awarded to Ist, 2nd and 3rd skippers. There will be no entry fee, but entries can only be accepted via affiliated clubs in the Midland District of the M.Y.A. Unattached enthusiasts, or indeed, those in other parts of the country wishing to enter, must therefore join one of the appropriate Midland clubs to qualify. programme was decided, it was also announced that district race fees would be reduced to the nominal charge of 5/- per race, and that clubs would not be required to forward district affiliation fees for the year 1952. Trent Vale M.Y. & P.B.C. We are indebted to Trent Vale secretary, J. W. Metcalf, for the heading picture this month, who sends it along for “the good of the cause”. This interesting A Class yacht Shangri-la was started in 1939 though “other business” prevented its comple- tion until 1945. It is a modified design based on E. G. Wade of Fleetwood’s Vanity IJ. Rib and plank construction is employed, using mahogany for keelson, and Western Red Cedar for the planks. It was first raced in 1947 in the National A Class at Fleetwood, and came 14th in a thirty-six yacht entry. Laid up until 1949 when she won the club championship. Again laid up until 1951 when she came out to take the M.D. Championship at Birmingham. The boat has proved easy and fast even in very light weather. Skeg and rudder were modified in 1948 to take Vane steering, when an earlier difficulty in gyeing was effectively cured. Technical details: L.O.A. 78.75 in.; L.W.L. 52.88 in.; Beam on L.W.L. 15.4 in. No Q.B.L. penalty. Sail Area 1618.74 sq. in. Rating 39.01. Shangri-la has now been taken over by a fellow club member and should be seen out again this season. 234 — March 1952 Poole Model Yacht & P.B.C. This club was re-formed in 1951 and is now very much alive. The culmination of a successful season’s sailing came in the form of a dinner at the Dolphin, Poole, with fifty-five members and friends in attendance. Mrs. Miller (wife of the Club’s President) presented prizes to winners of the Club Marblehead (50/800) Championship: Miller Shield—Mr. Beech; Runner-up (Hookey Cup) Tony Brook and Silver Spoon—E. Keech. In the Power Boat Section The Rotary Cup went to Graham Moore and the Silver Spoon to Mr. Morrell. At present the club is racing Marbleheads in more or less open water conditions, but the Poole Borough Council hope to complete a cat-walk for the club in June, thus completely enclosing the water. All being well, it is hoped to hold the South Western Area 10Rater Championship on this water on July 6th. Other enterprising work in hand includes the erection of a boathouse and seats for spectators. The local council have proved very co-operative and are including the club fixture list in the current issue of their “Guide to Poole”. Hon. Secretary of the Club is: Miss P. Robinson, 37 Valley Road, Bournemouth West. Paignton M.Y.C. Our remarks on Paignton M.Y.C. in January and February Model Makers have produced a reply from the Paignton U.D.C. written by their Entertainments and Publicity Manager, Mr. J. R. Bultz. We publish relevant extracts from their letter, together with Paignton Commodore Donovan Pinsent’s comments thereon, in order that readers may have a complete picture, and to avoid any feeling that may be engendered in that Council that our attitude is one-sided. Mr. Bultz writes: “. . . Paignton Council has been most generous to Paignton and D.M.Y.C., and is fully aware of its publicity value .. . When Goodrington Park was laid out. . . the Boating Lake was incorporated . . . as a means of obtaining revenue. After some time the Paignton and D.M.Y.C. was formed and granted facilities for using the Boating Lake on Sunday mornings . . . subsequently extended to Saturdays after 5 p.m. although it meant a loss in revenue of several hundreds of pounds . .. The rent charged the Club is purely nominal, as also is the rent... for the use of premises as a Club House”. Commodore Pinsent replies: “Re rent—we pay £10-a year for the use of the pond plus £15 for Club House. Nothing has been done to house for 17 years, the roof leaks very badly . .-. surveyor put in an estimate for £20 odd we were asked to pay £11 towards the cost. We then got permission to do the job ourselves which we did, materials costing us 10/-”. On alternative water Mr. Bultz says: . is an ornamental and water fowl lake .. . if it were possible to make this available to the Club it would be done as Council would then obtain more revenue from the Boating Lake . . . but alterations would ae Mr. J. W. finished in Metcalf's A Class yacht ‘'Shangri-la'', started in 1939 and 1945 which is beginning to make a name for herself in Midland District circles. affect the whole feature and deprive public of the attraction of the waterfowl . . . the Surveyor has reported that the lake could only be made suitable for “ec 235 sailing, i.e:, with safety to the Club’s members at considerable cost, which in these restricted times the Council is unable to expend”. Mr. Pinsent’s reply to this reports that the birds make a filthy mess of which everyone complains . . and that an estimate of £200 was reported as necessary on November 15th, 1951, to put pond in condition for club use. It was claimed that owing to bottom being of mud this was dangerous to model yachtsmen. If that was so it was surely dangerous in its present state and use with a sudden drop of 4 ft. In fact it was left to a member of the club to rescue a child there some years before. Finally, Mr. Bultz points out that the Council have always taken a live interest in the club, and that the appropriate Committee bears the expenses of entertaining Competitors in some of the important events. It says much for the optimism of officials that they have decided to recommence sailing on March Ist, and have scheduled the Royal Torbay Yacht Club Silver Rose Bowl event for 10-raters for April 6th, and the South West England 10-rater Championship will be held. at Poole on Sunday, July 6th. In view of general uncertainty the full club programme is still under discussion. Officials for 1952 are: President. Sir Reginald Leeds, Bart, R.N., High Sheriff of Devon; Vice-Presidents, T. S. Sharp, Esq., J.P., and Major G. Bentley; Commodore, D.-H. Pinsent; Hon. Secretary, L. Mullinger; Treasurer, L. Chenowith; Racing Secretary, F. Austin.