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APRIL 1972 15p U.S.A. & Canada Seventy-five cents HOBBY MAGAZINE 1 ice Hn me bereonteeed em) emi se | ws] tmeot ‘ i MODEL BOATS heeting Systems for R/C Yachts Part Five of our 42 in. one-design R/C yacht ‘Star-C’ by Vic Smeed Ppthe answer to radio in smaller yachts will probably be forthcoming in the near future when some of the sheeting units currently under development by more than one manufacturer are available. There are winches now (Graupner, Klug and Simprop) but these are a little on the large side. The only one we have had sent for examination is the Graupner one (see photo) which weighs 74 ozs. and needs a 6v power supply, bringing the installation weight to around the 14 Ib. mark, fine for a Marblehead or larger, but heavier than is really necessary for our size, though just acceptable. Also illustrated is a prototype sail winch/rudder combined ‘brick’ under development by SLM which, replacing normal servos, runs off the receiver power supply and weighs about 4+ ozs. This, even with larger receiver Deacs and batteries, means a very compact and light system. There is about 12 ins. of travel on the sheets on our pre-production test example, giving about 2 lb. pull, which should be enough for all but gale conditions. Many R/C yachts are already sailing with sheet winches made from drums mounted on Richard sixspeed geared Monoperms (currently £3.45) with a 3 or 44 v supply switched by means of two microswitches mounted adjacent to a conventional servo so that the servo arm depresses one switch or the other when keyed. With this system there is no real need for limit switches if three or four spare turns are wound on to the drums with the sheets fully out. Weight-wise, the motor/gearbox is about 4 ozs. and a separate battery supply is needed (this could be 3 v for sheeting out and 4+ v for sheeting in) so that the suggested 1} lb. limit of equipment weight is likely to be approached. An advantage is the simplicity of changing the gear ratio. Winches, i.e. drums, seem to hold the edge as a sheeting system at present. A cycle time (i.e. home to out to home) of 7-8 secs. seems average, and 14-34 lb. pull seems the usual power. With drums, braided flax line is best, as it is limp and less likely to tangle than a line with springy coils; in any event, separate drums are needed to avoid one sheet being trapped under later turns of the other, hence upsetting boom relationship, and a feed-on guide is essential. Excrescences on the deck (for example the rudder servo arm with above-deck linkage) form possible snagging points and should be covered; sections cut from stiff ‘blister’ packaging taped over is one suggestion. Troubles usually arise when the sails swing in and leave slack in the sheets, so another possibility is to use a longish length of shirring elastic to put a lightly tensioned dog-leg in each sheet. The cheapest sail mechanism we have been able to evolve costs under £1 to make and is perhaps the second most popular principle for sheet operation, METAL STRIP BENT-UP AL. SHEET TUBE OR WIRE 3 PART 173a TWIN SCREWEYES ‘“°-FILE OFF THREAD | PART 63b , PART 79a WASHERS AND SPRING [oerMiike: iin | 7 OT = (e) X BRASS TUBE OR WIRE AP RYE ES 9372 Fig. 4 pens shows to what hap- the sheets to double their travel. Both sheets are secured to A and pass through the jockey eyes at B, thence through a grommet C to deck eyes D. They are then terminated in hooks E, which hook either into the boom eyes or into small loops in jacklines on: the booms. As B moves, obviously twice the amount of sheet is taken up or released as would be if the sheets were just tied to B. with certain advantages over drums. It uses the wellestablished screwed-rod servo idea and can be made from several standard Meccano parts. Methods of construction are sketched; the variation of rod (or tube) or sheet metal as a jockey guide are the main differences. Quite an inexpensive motor geared or pulleyed to the rod is adequate, and to avoid stalling it or the complications of limit switches, the thread is filed off the rod so that the jockey runs up to the light spring (at either end), compresses it, and runs off the thread. The rod can thus rotate freely, but when its rotation is reversed, the spring pressure pushes the jockey back on to the thread. By making off the sheets to an eye screwed into a deck beam forward of the mechanism and passing the sheets through two eyes on the jockey, thence through a grommet in the deck to the booms. the effective travel is doubled, i.e. 6 ins. of jockey movement pulls in 12 ins. of sheet. An alternative switch system is to use a threeposition (off and two ons) car dashboard switch linked by a wire push-rod to a servo arm. The finger toggle of the switch can be drilled for the push-rod in such a position that the throw of the servo is adequate for positive switching. One clear advantage of a screwed rod_ sheet mechanism is that however hard the sails pull, they cannot move the jockey. The only other way of locking against sail pull is by incorporating a worm at some stage. Electronic locking is automatic with the feedback pot in most proportional servos, but presumably this could be overcome with a strong enough pull on the sheets. In practice, spur gears of sufficient reduction need a considerable force to ‘unwind’, and this is proved by the wide and successful use of the Richard gearbox mentioned. The original Star-C is fitted with a pivoting arm bolted direct to the output arm of one of the Flight Link’s high-torque servos. This servo gives 94 lbs. pull, but this is reduced by the length of the pivot Nearest, the SLM ‘brick’ which includes both rudder and winch. This preproduction example _ is being fitted in our model for test purposes; it makes a very neat and easy installation. On its right is the Graupner winch, a very sound de- aie which Ib. pull gives for about 10 in. travel or up to 30 in. travel with 5 Ib. pull. Price is £16.85. Above, far less sophisticated is the simple screwed-rod mechanism built almost entirely from Meccano parts. This one’ gives about 10 in. travel but pull depends on_ the motor fitted. 157 arm (33 ins. each side) and by the use of fixed-end sheets, i.e. doubling the sheet travel by the method already described. This works well in the light conditions so far encountered, but whether it will provide the necessary power in 15-20 m.p.h. winds is something we have not yet been able to check. We have seen similar systems in photographs, but probably these were not taken direct off a servo. A big advantage is the low total weight, 14+ ozs. in this case, but it is obviously better to go up a bit in weight to have an all-weather system, if, as seems possible, we are asking too much of the servo. Occasionally we are asked about the desirabilit of independent jib sheeting. Well, it can help to tac a boat quickly, but since most sailing is taking place some distance away, it is not easy to see that it is sheeted to the best possible position. Maintaining the same relative sail angles by common sheeting is likely to prove more efficient; the boat will sail faster between marks and this may outweigh the one or two seconds which may be gained in turning the marks or tacking quicker on the windward leg. Perhaps the answer lies in the length of a particular course, wind conditions, and the individual skipper. Most feel that separate sheeting is unhelpful in actual racing. We have already been asked to allocate sail numbers to Star-C owners and, as this is an essential step towards eventual official recognition, invite owners to write in for a sail number. No obligations involved! MODEL BOATS Readers Write… A wallet of chrome-vanadium spanners in the small B.A. sizes is sent to writers of letters offering something new or interesting to say. UNPUBLISHED DESIGNS Dear Sir, In way of reply to Mr. Stollery’s letter (January Mode/ Boats), he correctly points out that the unpublished lines of successful yachts are on view ‘in the flesh” most weekends. However, there are relative backwaters in the model sailing world, such as my own, where we do not get to see the most successful designs as frequently as the Southern and Metropolitan clubs. Indeed, for most of the Dovercourt, and | think | may say the Eastern area members, last year’s Model Maker Trophy was their first taste of racing against a fleet of first-rate modern designs. Should these designs be published, from a purely constructional point of view there seems to be little encouragement for the beginner to construct a lightweight or turtle deck boat. But the would-be designer then has the opportunity of finding from the plans factors of a _boat’s performance such as wetted area, beam, stability and draught which cannot be gathered from the actual boat. On a similar note, apologies to Mr. Shepherd who is incorrectly credited as the designer of my own Marblehead (M.M. Trophy Report, December issue); it was designed by Mr. Dunster. Witham, Essex G. Bantock R/C YACHT COSTS Dear Sir, After reading the letters on R/C in ‘Readers Write’ of the February issue, | feel that | must reply to the question of why the Q Class has met with so little success during the past few years. As Secretary of the Eastbourne and District M.Y.C., | must also take to task Mr. Gould on his remarks on some members of my Club and the insinuated lack of interest on the day that he visited Eastbourne. do not think anyone can impose upon others something that they do not want or cannot have. There are members of my Club who just do not want anything to do with R/C and, then again, there are some who have just that amount of initial interest but who cannot afford the extra expense of radio gear — £50 or over is a lot of money when one is also faced with the cost of building a new boat. Take, for example, a person who is unable for any reason to turn out his own fittings or make a suit of sails. Sails cost, when made commercially or by other model yachtsmen, from £2 to £5 per suit according to the class of boat and the size required and, as it is usual to have at least three suits, then in the region of £10 is spent on them. No, £80 is more than most of my members could afford or would wish to spend on a Q Class yacht. Free-sailing — the ultimate of the model yachtsman’s skill of sail trimming and vane setting —is obviously preferred and to point a little higher on a beat to windward than one’s Opponent creates a great sense of satisfaction and to know also that one’s experience and skill have mastered perhaps for a short time the weather conditions of the day. | must agree with both Mr. Gearey and Mr. Gould that any boat smaller than an “‘M’ is too small for R/C. My personal preference, if | were a convert to R/C, would be to modify a six-metre boat. These boats, in my view, have the three qualities for an R/C Class, namely, size, weight and appearance. Classes have had their years of being popular and, who knows, it may be the 10-r that will in the future decline and lose its popularity in this country as something else takes its place. At the moment, | cannot see it being the Q Class. As to Mr. Gould’s remarks on ‘the elderly gents’ of my Club, | must first dispel the impression that we at Eastbourne may all be in that category or even that we are not competent model yachtsmen. Believe me, to sail on our sailing water is an experience not lightly forgotten, and | would say that, after learning to sail on it, one could sail anywhere. So far as | am aware, Mr. Gould has only paid us a visit once. The Club has a number of members who are on the other side of 65 and, in fact, some over 75 and we also have, just for the record, quite a number of junior members. Some of the former are founder members of the Club, now in its 45th year, and still obtain a fot of pleasure from seeing a model yacht sailing. Two of them, one in his 81st year and who has been a member of the Hastings and the Hove and Brighton Clubs, and the other in his 70s who must, | feel, be the members to whom Mr. Gould refers in his letter, like to participate every Sunday morning in the Club’s racing events. Who would dare deprive them of this enjoyment; certainly no one in my Club. | dare sav these ‘elderly gents’ have been model vachtsmen now for more vears than Mr. Gould would care to add up of his own, but then not having met him perhaps that is a little unfair. As to the lack of interest shown in Mr. Gould’‘s R/C yacht, the Club and especially the Commodore and myself would have offered to him every courtesy had he written to or telephoned me_ beforehand and told me that he was paving Eastbourne a visit. He advocates this course in his own letter to those who would wish to visit his sailing water. We could then have aired our views on the pros and cons of R/C class sailing. Polegate G. E. Stacey MORE R/C YACHT COSTS Dear Sir, | have just read with interest Mr. C. S. Gould’s letter regarding the growth of R/C model yachts in his club. | have little comment on his arguments about size and class of boat that should be radio controlled, except to say that any size of boat that gets yet another person interested in model boating is to be encouraged, and a small boat that a small young person can handle by himself, is far better than a big one he can’t. Interest — there is plenty of that, even in Eastbourne! but more to the point, might be the lack of spare cash even in these affluent days (?). To find £50 (Mr. Gould’s figures) just like that for radio gear? Our youngest members still at school, and those elderly gents on retirement pensions, could well find that sort of money to spend on a hobby quite beyond them. Even some of those at work, and looking elderly to some people, especially the very young, might think twice before taking such a sum out of the family budget. What 164 is wanted is a good constructional article on how to build your own radio gear, to find the faults that might crop up, and how to maintain it, at a price a lot of people could afford. How about it Mr. Gould? | did have a go, but not having too much to spare and a local dealer who knew, if that is possible, less than | did, | bought what turned out to be the wrong kit. Oh yes, it did work, and quite well, but having been on the dealer’s shelves for a long time it still had valves, and the batteries required to run it made each outing somewhat expensive, not counting the weight that had to be lugged around. I’ve asked around, bought magazines and books. but couldn’t get the answers, not even from Radio Control Models, or so-called experts who just said: ‘Oh my gear cost £200’ — collapse of this stout, nearly elderly gent, There’ certainly seems to be a gap that could be filled and some beginners’ articles by a real expert in this line might encourage far more interest, but do keep the cost down of the finished article. The Eastbourne Club is having a hard fight to keep going ever since the Cor- poration sold to a commercial firm the boating concession on this lake. This restricts our opportunity to. practise, train youngsters, hold meetings, etc. | was lucky enough to get on to the Executive Committee of the Eastbourne Sports Advisory Council to help present their case and other sports matters in the district. It’s the old, old story. In spite of this | have no doubt that one spritely young octogenarian will show Mr. Gould how to sail vane gear on this lake if he cares to spend a modest fiver on a gear for his Tornado, and literally aive him a good run for his money. | feel it only fair to warn Mr. Gould we might have a quiet giggle when his Tornado emulates a white Tornado and disappears, like the celebrated Ouzalem bird, up its own rigging when it gets past the cafe aoing westward! N. Sylvester Bexhill-on-Sea R/C YACHT SIZE f Dear Sir, May | congratulate you on producing the first concrete suggestion for a new R/C yacht class — | wish you _ every success with it. After all the talk that has been going on, it is good to see done. Were something actually el it not for the fact that | am half way | would be Cervia a building through making a Star-C, without a doubt, and then that successful proves class if the will be my next boat. Which brings me to my ‘ main z point. In all the correspondence that has been published in your excellent magazine. so many people have made the point that anvthing smaller than a Marblehead is (a) invisible at 100 yards or so, and (b) unsatisfying to sail if anything larger has already been used sailing am speaking as a newfree. Now, comer to R/C yachting, and a young one as well (I’m 16) — I’ve been sailing power boats for four years but found it too expensive. To answer point (a): Why do small boats have to be sailed on the same courses as the big ones? Four or five Starlets on a 50 yard triangle gives great sailing and anyone who can‘t see a Starlet at that distance is a hazard to shipping! (b) Why this assumption that people have sailed anything larger? Obviously this point is valid if Marbleheads and 10Rs have been used but not everyone has. Here | must admit | am speaking from my side — as a young beginner, but | think the size of the new class is ideal for beginners — | mean complete beginners, not people who have had free sailing ae ae APRIL experience, of any age. Size does put people off, a Marblehead is too big un- less you can store it near the pond, for someone who has a bedroom as a workshop and a feng eutednd father as transport facilities. lot of my friends, building or thinking of building of R/C yachts, have opted for the smaller classes such as Starlet and Cervia purely because they are about half the weight and bulk to wa/k the pond with. (In my case around a mile and a half.) | may be going at this a bit hard, but unless new life is installed in our end of the sport, i.e. the younger generation, it will never carry on. So don’t knock the new class too hard, it’s just what we want really. If Mr. Gould is so gone on head him, with but his 60 in. class overhangs) I’m certain (or Marble- good it’s not luck what to is needed. Oh, another point which Mr. Gould made, which annoyed me a lot, was saying that he wanted a boat which would justify the installation of at least £50 worth of gear — not many juniors have £50 to spend on gear; perfectly good control may be obtained with single-channel on a small yacht, but single-channel proportional can be bought for around £30, slightly more within reach. | notice from Mr. Gould’s articles that he uses no sail winches, and reed gear is available secondhand for £20-£30 with servos, as mine was. Enough said? Many thanks for an interesting and very informative 15p’s worth of magazine. Uttoxeter D. J. Eastwood MORE R/C YACHTS Dear Sir, | would like to send a note of thanks to Mr. Vic Smeed on designing the Star-C R/C yacht. | think that it is just the thing we want as it is small enough for a modeller to build without the aid of a complete workshop, but most important, he is keeping the cost down which | think is very important if we want to attract more young people into the sport. After reading three letters on the subject in February’s Model Boats, | was prompted to write a reply. The three yachtsmen must sincerely realise that a lot of people cannot afford the £50 that was quoted in one letter. | myself sail a 36 in. (Plane Jane) model with a single channel R/C, from which | get a lot of enjoyment and as far as visibility is concerned, | sail with the Port Talbot Model Boat Club and their waters are Port Talbot Docks. which are closed to shipping now. | don’t think there are many clubs in the country that can say they have a water as large as that, but | have no difficulty in sailing my yacht under these condi- tions and once again | say to Mr. Smeed, keep the good work up and try to keep the price down to attract more neople to the sport. Swansea J. R. Wright AND MORE AGAIN Dear Sir, Several points arise from the letters in February Model Boats. Why should Mr. C. S. Gould wish to develop yachting hulls but be satisfied with leaving sails undeveloped, surely a more urgent problem at present than hull design? And, will all skippers become first-class with radio? The main thing that arises from both letters is that neither writer appears willing to travel further than their sport/ hobby, but if they are, how about both of them coming to a National event, say the ‘M’ Team race at Wilton, to race or/and demonstrate during the lunch-break? Regarding size, | would love an ‘A’, but our local puddle will hardly take an ‘M’, 36 in. being ideal, There are more ponds available to modellers of our size than that of Gosport or Fleetwood, but they are unused for organised yachting due to the predominance of the larger yachts. As to Star-C, / would prefer more sail — the ponds mentioned above are usually found in parks and are treebound (Park Superintendents equate ‘water’ and ‘pretty’ with ‘trees’) -— and also a development class. | have no wish to sail a pre-war ‘M’ or 36 in. To say that with a one-design, all are equal is no consolation when, sailing on the local pond, a different but smaller boat comes sailing past. Anyway, all the best with the new boat. Harry Briggs Grimsby. GOOD CAUSE Dear Sir, | have the privilege of running a small model boat club for young lads who are in care, either because they have unstable parents or none at all. All are between 11-14 years and, | am told, have below average 1.Q. However, | am constantly amazed with the standard of their work and the tenacity they have to finish their models. All have made at least one working model of their own and are now engaged in jointly building two launches from M.M. plans. Naturally, we have difficulties financially, but with jumble sales, etc., are able to keep going. However, the expensive items such as_ radio and motors make a hole in our budget and | would like to make an appeal to your readers, and clubs, not for money, but for any scrap materials, unwanted equipment, etc. We can find a good home for any such items, as the lads are taught to adapt and make do with anything we can get our hands on. Springfield Registered Hengist Road, Westgate-on-Sea. R. J. Pollitt Nursing Home, MINAS GERAIS Dear Sir, | was very interested in Mr. M. Ainsworth’s account of Minas Gerais, she was a beautiful ship which | recollect quite clearly for | saw her very. frequently; | had an experience aboard of her which | shall relate. Minas Gerais was built and completed’ on the River Tyne by Arm- strong’s but not at the qreat yard above the two bridges at Newcastle upon Tyne. wick; naval This yard was situated at Elsit had been decided that as the tonnage was becoming so great it would be impossible for it to pass down river through the bridges as the beam was becoming too great; the last warship to pass through the bridges eastwards was H.M.S. Monarch. This ship had done so a few years before the building of Minas Gerais. Future shipbuilding was discontinued at Elswick and a new yard was established at Walker; firstly it was owned by Armstrong, then it was taken over by Vickers, now | believe it is in the Swan, Hunter Consortium. It is still known as the Walker Naval Yard, a huge concern, but it began in a small way when Minas Gerais was the first warship to be built there, The date given for her completion is January 1910, this is an error for the ship left the Jarrow Slake Buoys in 165 June Tyne. 1909; she never returned 1972 to the While this ship was building my father was skippering and running an interesting steam wherry carrying ship’s stores and any other available goods; her interesting feature was that she had a compound, condensing engine and there was only one other with a similar feature though there were dozens of steam wherries with compound, noncondensing engines. At this time | was at school and spent a// my free time in the wherry. Saturday was then a working day, for the five day week only applied to teachers. Bee fine Saturday in 1909 a parcel of steam packing was delivered to the wherry to be delivered to Minas Gerais, it was from the quayside shop of George Angus & Co. which closed on Saturday afternoons so no assistant was sent with it to get a signed receipt. My father, not knowing what | would have to face, asked me to take the parcel on board this great ship. | reported to a policeman on board who gave me vague instructions how to proceed to the engine room, but when | got down the first ladder | was amazed and staggered at the complicated passage ways with which | was faced; | was only 16 years old and had never been faced with a ship of this size and it was not long before | was hopelessly lost in this new world. Only the foreign crew were in evidence and what a job J had before | could make anyone understand where | wanted to be. Finally | did arrive but had no idea how to get back to the deck. After some two hours had elapsed | finally made it just as my father was arranging with the police to institute a search for me; of course there were no lifts on board ships in those far off days. : Of course | had to put up with a tremendous amount of chaff by those who had no conception of what it was like below the deck of a ship | shall never forget. Newcastle upon Tyne Wm. Featherston VIEWPOINT Dear Sir, Where have all the power boats gone? This question must make sense when established power boat enthusiasts reflect on the regatta atmosphere of yesterday, remembering with satisfaction the enclosure behind the _ boathouse at Victoria Park and other famous pondsides, and the interest promoted by each competitor as he prepared his craft, lifting superstructures to reveal well designed and constructed power plants. : aad There were hardly two bearing similarity. What a pity that each regatta now consists of lining the pondside with just competition boats. Today’s power boat often takes the form of a glass-reinforced plastic hull fitted with a stock noise producing miniature engine or the big sister from the lawn mower. ’ From the writer’s point of view, there is no reason why owners should want to display the engine room. What is there to constitute model engineering? The craft are merely functional (1 like this term promoted by _ the M.P.B.A.), working miniature boats, often horribly put together with standard components to get the boat afloat as quickly as possible to compete with the next man. It is not unusual to see unpainted plywood decks, roughly soldered up tinplate tanks, a yard and a half of plastic tube (or rubber) and _ other eye-offending monstrosities. Little wonder that as each Model Engineer Ex-
