- Title. Author. Summary
© Plastic tape seal l Deck f FIG. 2 1 FLUSH SHOEBOX Ky} vs Acrylic Cover Ply Collar FIG. 3 SLIDING SLAB ae mE t u we A nfs [RS FIG. Rubber band To Eye in Hull ae Fitted Pop-Top Wee Decking Cover YANKEE SHOEBOX —_S— ae ad Era = es: Seca FLUSH DECK HATCH COVERS STRICTL ‘SA By ROD CARR @ | am often asked why | spend so much time on the 50/800 class. The answer is simple, Lots that is where of boats sailing, the activity is. lots of people building … but most importantly, lots of folks willing to share their ideas in FIG. 4 order to improve our hobby. This month, all the way from ‘down under”, | am pleased to feature a new 50/800 design, never before published, by Adrian Brewer. He offers for sale his design Laminated Pop-Top here is what he had to say about SONIC BOOM Il: “The lines of Sonic Boom II are the latest result in a family of designs beginning in 1968. “At that time, | received a private commission to design a boat to a specific set of requirements which included narrow beam and canoe stern. This concept did quite well in vane competition, and two variations on the one theme evolved, but after watching the boats compete in various conditions, | con- cluded that several improvements could be made. | then re-drew the lines by spreading the beam by 1.5 inches and incorporating a narrow transom which increased displacement to around 17 Ibs. This boat was almost unbeatable to services. so if vou wish to have a specific hull idea exploited on his drawing board, contact him directly at 6 Queens Square, Sandringham, Victoria 3191, Australia. He has in stock plans for a number of A-class designs, as well as other 50/800’s, which cost in the four to five dollar range. His SONIC BOOM II has won the 1975 Australian Championships which is about as good a recommendation as one can have. We all owe Adrian a debt of gratitude, since he has released this design with no strings attached. There is no one better qualified to comment than the designer himself and Tension on A is transferred to C and multiplied by the ratio of S + R. Result is a harder pull down on the boom. FIG. 5 Modification of J. G. Products Radial Jib Fitting Jib club swivel pin Washer spacer Shim for alignment J. G. Products Masthead Fittings 36 Deck line MODEL BUILDER was given a much MMe boat flared bow (which gained it the name ‘Aircraft Carrier’) reduced rocker and a This ~~ Boom. MOLL LMS / “A further re-think was necessary, and the new lines resulted in Sonic LOONIE Ate PAL run was very mediocre. – windward and reaching, but on a square fuller stern, resulting in a slightly wider transom. Incidentally, | notice with interest that Chris Dicks, a top English designer, used an identical bow in his recent “Illusion” design. | was almost there . . . very fast to windward and she could really move downwind. But downwind there was still one problem… the way she approached a wave in a wind gust determined whether she rapidly planed away or went through the wave and continued at full speed underwater, irrespective of the bow flare! This could be cured under vane by a well-cut lifting spinnaker, but it was not good enough for radio. “Nevertheless, she had good success in competition with a 4th in the 1974 Australian Championships and winner in 1975. She also won the Victorian State Championships 1975 and never lost a Club event. Needless tosay | was delighted! “Sonic Boom II is a direct development of this boat, but more suited to inch nosing which to try and the former design was prone to do. These small alterations improved the design and | can confidently recommend her to any- one wanting a fast ‘RM’. | have produced her in fiberglas in Australia and there are many now sailing. “! am Australian fortunate that the current ‘RM’ champion is from my Club (Albert Park Model Yacht Club) international event in England, TM~ ~ ~ and he is a good-yard stick for my own design. His boat, ‘Fes Gee’, is very similar in general appearance to the Swedish boat which won at the recent and performance would seem to be similar. His best win at the Australian ChamPionships was over 5 minutes ahead of the second boat home (fleet racing over a triangular course | of approximately 500 meters and light winds), and his iY worst win was 2 minutes 55 seconds. Naturally, he won all races. Sonic Boom rah ‘ Il is quite capable of beating ‘Fes Gee’ over all except drifting wind conditions, and Sonic Boom |! has just won the 1976 Club Championship, second. with ‘Fes | Gee’ “She planes well and easily under / she easily beats the ‘RA’ boats around the course. “If any readers decide to build her, Seren working sails, and is very fast to windward. In fact, in Club handicap races ee, | ’ ES 2 a ey, another the ‘ Y wey raised prevent _ Ue EY ER oe ad but | ee ae by 1 lb. The flared bow was maintained, cle the stern and filling out the bows slightly, which raised the displacement ee underwater volume of the eS SS The =< radio, hull was slightly re-adjusted by widening Continued on page 79 SEPTEMBER 1976 FULL SIZE PLANS AVAILABLE — SEE PAGE 104 37 QGarab a fhanadtusll® rialS channel Compact lightweight design, top line components. quality handcrafting. precise control functions make our new 3-Channel Radio Control System the trend setter of the industry. A system you'll have the utmost confidence in. Training. competing, or just enjoying yourself, use the best, use RS. See your local dealer and tell him you want to “Grab A Handful" of RS/3-SO, or contact us directly. RS Systems A _jih Sy — if Canada: AS Systema of Canada, 2050 Mansheld Montreal, Quebec A maximum of 45 seconds engine run was allowed, on two official flights. And did you notice the landing points? Duration is of no importance, so the idea is to make your ship ‘‘stick around.” H3A that battery-driven cam steering device from the Mattel bird, or that pre- programmed Stutz Bearcat?) BACK TO “WINGED VICTORY” There probably weren’t too many duplications of “WV” (Is that a “Bug” with the engine in front?) back in the early days, because Joe’s construction techniques were quite beyond the average builder. The cowl alone was a masterpiece of spun and formed sheet metal. However, with today’s materials, especially fiberglas and epoxy glue, the model should be a lot easier to recreate now than then. And we gotta contradict our own earlier comments about the precision event . . . this beauty is a super-natural for R/C! According to our loose calculations, K&B’s new .21 (3.5 engine is a perfect powerplant, based on SAM’s 225 sq. in. area-per.10 cu. in. displacement rule. Incidentally, Joe now lives in the San Diego area of Southern California, and in case some of the photos with this article look a little familiar to our genuine old time modeler readers... they should! We informed Joe of our intentions of republishing the “Winged SEPTEMBER 1976 1¥9 Canada | gnomey Telephone: (301) 474-2900 . Victory”, and lo and behold, he came up with the original negatives of the the original article. How about that! photos used j igi M.A.N. : Continued from page 37 (Hmmm ... wonder what we did with cc) COMPANY 5301 Holland Dr.. Beltsville, Md. 20705 | would appreciate feed-back of how she CLAMPING |WATER P| CK-U |p ASSE MI eB LY performs against the top American dei i the only way for development to continue. there is one point wish to emphasize which has been said many times before. The design of the hull and rig is only a small part of what goes to make a successful . Good sails are critical, and if everything from cut down to setting Is 100% correct, it is the same as irying to race a V-8 engine power boat which is firing on only six cylinders. But most important is the chap with the transmitter. Even the most highlytuned boat will perform like a log in certain hands. There are no short cuts to the trophy circle, so watch and talk with the top skippers and apply what “In conclusion, you learn to your own sailing. To those co > of you who build Sonic Boom If, 1 wish LEE, the general trend in 50/800’s. As far as | existing M.S. Rudder/Outdrive Assembly you every success.”’ can tell, Sonic Boom II ts right in the middle of the displacement range, which is proving to be the best for all around performance. Earlier designs were hoping ees CWPA $1.95 or mounted directly on the hull. P.O. Box 588, Saratoga, Ca. 95070 Catalog $1.00 Dealer Inquiries Invited 79 block and tackle arrangements to give the mechanical advantage needed for firm vang tension. But from the full- TRIDENT II racine trimaran For ric sized racing classes comes the lever vang. FIRST PLACE IN 1974 AND 1975 36-600 ACCR REGATTAS eSTYRENE HULLS AND DECKS 036″ LOA. ©36″ BEAM © COMPLETE PLANS The ®SEWN DACRON SAILS *HARDWARE e600 SQ. IN. °6.5 LBS. DISPLACEMENT COMPLETE KIT (LESS WINCH) ae ae $100.00 $50.00 SAIL CONTROL WINCH CUSTOM R/C DESIGN FOR ALL BOAT SIZES rubber band, as it is doing nothing but keeping the lever plate in the plane of VOLTAGE 4.8 -6V. LIGHT — — 8 OZ. the mast and boom. | would expect that a brass or aluminum lever plate would be good, though hefty bakelite SMALL — 2″x2″x5” FIRST PLACE IN 1973 S/B ACCR, might ‘ ‘74 36-600 ACCR AND ‘75 50-800 ACCR STAINLESS STEEL HARDWARE: Turnbuckles, Chainplates, Goosenecks, Boom vang pivots, Pad eyes, Tangs, Deck cleats, Boom clasts, Rigging wire. MISCELLANEOUS ITEMS Sheet exit guides, Bowsie, ESCONDIDO, CA. 92025 Yankee’s displacement even more, and is now sailing an 11.5 pound boat. Sticking with a very low aspect rig, much like the Soling’s, the boat has produced Yankee II. She is fuller for- shown ward than her progenitor, to prevent downwind nosediving, and she has had her underbody enlarged to produce a reaches. _But on the general power has on heavy air with an suffered boat will eventually be having movable ballast! protested for Having just taken delivery of some new radio gear with 7 channels to play with, | returned to thoughts of more adjustability on the boats I sail. hull wetted surface of the Yankee hull. John may be due to the hatch being constructed as an afterthought, instead of being built in as an integral part of the hull/deck. Im order of importance, a good hatch should be: 1. Watertight 2. Easy to open 3. Snag proof 4. Transparent 5. Water proof 6. Light weight The first requirement is obvious, yet 5 out of every 10 hatches that I see leak like sieves. The second requirement can be obviated somewhat if you contrive a method of turning the electronics on and off without having to enter the interior of the boat. A waterproof toggle which fits through the deck in an unob- trusive place like the base of the mast is available from Harris Engineering, 7628 arrangement to be able to control the amount of twist in the mainsail while | have also seen a magnetic switching the reaching and running. Current designs form have been attempts to reduce the an indication of how much vang tension you have set. BATTEN YOUR HATCH Of all the individual sub-systems on our boats, the hatch seems to be one of the most prone to misfunction. This top of the list was a vang At bow for want of an easy name. attacks it extremely loose keelbulb arrangement, which is so floppy that I’m afraid the final displacement in the 16.5 to 17 pound range. This is certainly a parallel design evolution to Sonic Boom Il. Al the same time, we have seen Chris Dicks and Roger Stollery start to experiment with the “aircraft carrier’ type of bow form. I think 1’I! call it a Saratoga Other extreme Make sure that stay under such tension. And use a trimmable Huson, of Leisure Products, took a production Yankee off the line and removed a symmetrical wedge from the centerline, which had no width at the bow and widened to almost 3 inches at the transom, By so doing, he reduced the in Florida showed that an extra pound of lead or so did much to up her momentum and help her carry through her tacks in rougher water, At the same time, the Yankce’s designer, Chet Purdy, was hard at work on the concept and has too. servo so that the transmitter control is Rudder posts, Mast head fitting. Oacron sheet line. PROBAR DESIGN her work wire is used wherever possible, as sheet line would have a tendency to fray Dealer inquines snerted. to exploit the benefits of acceleration, or else put a turnbuckle in ‘A’ and you can probably drop your boom an inch or so, reduce your heeling and gain some The line indicated at ‘B’ can just be a FAST — —5 SEC. and a good example of that is the original Yankee which weighed in at 13.5 Ibs on her designed lines. Experiments with trollable one by leading line ‘A’ down through the deck to a hi-power servo, end plate effect. POWER — 40 IN. LB. P.O. BOX 639 arrangement shown in the figure can be adapted to either an R/C con- are generally too complicated, utilizing Dunston St., Springfield, VA 22151. arrangement that was demonstrated by Vince Serio of Sail Engineering, P.O. Box 8439, Richmond, VA 23226, at the Toledo Show. Such extra efforts are well worth the trouble. | have been CARR SAILS using one of the Harris switches and am well pleased. It also helps speed up regattas, as you are able to clear your frequency for a partner as soon as you 7608 GRESHAM ST. SPRINGFIELD, VA. 22151 STANDARO ON AlL CAAR Finest American-made Vinyl, press-on get your hand on the boat. A snag-proof hatch DACROW salicloth. numerals and Insignia. Heat sealed edges eliminate fraying. Coated,stainiess stee)] jibstay installed. Rolled-edge grommets In tack,clew A head. Bolt-rope mains‘) tuff mast attachment. A teat Santa East Barbara Coast 36/600 West Coast – – |2- Meter = [2-‘eter Vanguard “J”-boat Scale for a 80 – ~ – $30.00 $30.00 $25.00 – = – $30.00 $L0.00 10-Rater ~ – ~ $30.00 A-class- £35.00 50/800(M-class) Internat. is an absolute must. All edges must be rounded, with no cracks for a sheet to wriggle under. A good way to handle this is to choose SAILS Star 4S TAA Petre] – – $36.00 = $30.00 = $30.00 vassels, spectal purpose boats, ane-of-a-kinds: quote, and for our 1975 Brochure and Used Salts Write Lise. a hatch configuration that is flush with the deck. Figure I. shows some variations. The tape seals are excellent if you do not have to continually open and shut them. | tape my boat twice; once just before the event starts, and a second time at lunch when [ put in al! new MODEL BUILDER batteries. | make sure that the new tape goes down on an absolutely dry deck, and keep a handful of towels for just that purpose. While the tape may be ugly, it is light, easily removable, and will not need to be on the boat when it is being viewed close-up on display. The mechanical simplicity is a great benefit. | prefer a transparent cover just for the ease with which one may check his bilges, and see that batteries haven’t ‘(COMPLETE r + With our modern, engineered system of stainless steel deck and sail rig hardware and extruded aluminum spars. R/C YACHT KITS And with Vortex-made sails FROM $358 and fiberglass parts ofa precision and finish thatis TO $395 just shifted. It is one more way to eliminate a continual opening of the boat between heats. Waterproof seems to be a foregone conclusion, yet many skippers will go the tape Approximately 330 carefully organized items in each kit. Sixty-page, step-by-step assembly manual includes route, and inadvertantly use complete control equipment masking tape of the variety which soaks up water, loses its adhesive ability, and ceases to act as a barrier to the onrushing installation drawings for two or three channel radio and Vortex SC-3 sail control unit. waves. A lightweight hatch cover is a continuation of the practice of keeping Mail order only. theme (Fig. incorporated 2). a Some builders have foam gasket at points Aand/or B in these arrangements, which the rubber band pulls the hatch cover into, One can also investigate the round plastic access hole covers that are marketed by the yachting supply stores for racing dinghys. These have a round screw top that comes off with a twist. They come ina series of diameters and a selection of colors, from such companies as Holt Allen. On a couple of Canadian boats, | saw a configuration which can only be described as the Sliding Slab. The actual cover slides into a slot which runs forward and across the front of the hatch coaming. I’m not sure exactly how the after end was sealed, but it might have been a lift-off rear coaming, or a gasket seal thal was compressed by the slab. Its watertight integrity depended on the care and clearance allowed in the slot-to-slab joint. A popular general category of hatch cover is the Fitted Pop-Top. The SOLING is a typical example of this. A sheet ABS or acrylic cover is vacuum molded over a plug which matches the coaming raised in the deck of the boat. Depending on where the sheets run, | have scen snags on this type if they are not carefully pulled down tightly against the deck, SEPTEMBER 1976 infor- Write for mation as much weight in the keel of a boat as possible in order that she is able to carry sail and stay stiff. Lightweight does not mean flimsy,nor does it mean makeshift. A Saran-Wrap cover will be the inevitable target of Mr. Novice-On-Port-Tack, much to your dismay. If you can afford the weight, the Flush Shoe-Box is a good choice. lt will often require only a rubber-band tie down if you make a good fit while installing it. If you are putting a hatch on a boat which is already decked, the Yankee Shoe-Box, already described in these pages, Is a variation on the same not available anywhere else. 210 East Ortega Street Santa Barbara, CA 93101 Sailing Yachts For Radio Control FIBERGLASS, R/C TAHOE 600 4 PEMAQUID FRIENDSHIP SLOOP “FLORIDA” Hull Length 37° — LOA 56” “SIRIUS 45° NEW GLASS STAR 45 BOAT for AMYA Star 45 Class HULLS ® KITS @ READY TOSAIL Send 50¢ postage and handling for detals David Mainwaring PO BOX 554 NEEDHAM. MA 02192 Chuck Black used to build decks with the coaming, then use the coaming itself as a plug for a laminated pop-top. Common sense dictates that one make a spare cover if this method is used, and that the hatch cover itself be made sturdy but light to conform with our other requirements for a good hatch. I’m sure there are others but my plea for your suggestions fell upon deaf ears, with Chuck the only one to respond. To him go my thanks for his time and effort stolen from an otherwise unbelievably busy schedule. Meanwhile, at the other end of the mast, J.G, Products, 8030 Fordham Rd., Los Angeles, California 90045, is of- fering a selection AMYA 36/600 CLASS 36 In LENGTH 9 !¥@ in BEAM SAIL AREA GOG sq in $38.95 VALKYRIE AMYA 50/800 CLASS LENGTH BEAM 50 in 41% in $74.95 SAIL AREA B00 sq In Complete kits include molded plastic hull and components, all rigging. finished sails and semi-fipished wooden parts. TAHOE SAIL SYSTEM $27.95 VALKYRIE SAIL SYSTEM $35.95 VICTOR 11715 Adenmoor Ave. Downey, Ca. 90241 Calif residents add 6 ta DEALERS WELCOME of silicone bronze 81 Cobra 17 HIGH PERFORMANCE MODEL SAILPLANE WING SPAN Kestrel 19 HIGHEST PERFORMANCE MODEL SAILPLANE ……..+- 121.5 In. WING AREA ……… 717 sq. in. WING LOADING 10 02z. per sq. ft. ~ QUALITY ENGINEERED — (a 50 oz. OVERALL LENGTH > … ree 47 In. WEIGHT ……. 0.00. min. 50 oz. ASPECTRATIO = ……… 20.5:1 SCALE .” “Capri J = 16 Sabo 20000020
