24 May 2017

Introducing MMM Sail Division

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Metro Marine Modelers – Speaker Series Presentation – 28 April 2017

Presentation by David Allsebrook and Michael Steele

The concept behind the three one-design sailboat classes presented is that a first-time skipper should be able to build and sail a model yacht that has essentially no performance differences from a boat built by an expert. Class rules are intended to ensure that all boats are as close as possible in design and construction with regard to hull, deck, keel, rudder, sails, displacement and ballast. Performance therefore is the result of the skill of the skipper and not due to any design changes to the boat.

David first described his SOLING, an example of the SOLING One Meter Class, which is the largest class in the American Model Yachting Association (AMYA) and the Canadian Radio Yachting association (CYRA).

Soling SOLING dimensions are: Length 39.3” max, height 64.5” (keel to truck), beam 9.25”. Sail area 600 sq in.

Boats conforming to the class rules must be built from a kit obtained from an approved manufacturer. In Canada and USA the hulls, keels, rudders and decks are manufactured by one builder, Victor Model Products in Louisiana, USA, who supply the boat as a kit or fully assembled. Sails and parts are available from Leading Edge Hobbies in Kingston, Ontario

The mast and booms are made of solid wood or plywood. The sails are single-panel woven polyester fibre cloth, cut to the shape of the standard class drawings.

Sailing control is accomplished using a two-channel radio system, which controls the rudder and the set of the sails.

The ready-to-sail yacht must weigh at least 10 pounds. This includes the radio receiver, batteries, steering servo, sail control unit, sails and rigging. Ballast consists of lead shot permanently bonded into fibreglass resin poured into a molded keel.

The price of a complete boat kit, including mast, sails and electronics, is about $600. An unassembled kit, which includes the hull, deck, hatch, keel, rudder and all necessary support structure and hard-ware, is about $300. The radio, paint, glue, lead shot, a stand and fibreglass resin are extra.

David described how he tunes the rig of the boat, using the boat heeled to one side in its cradle. Gravity on the sails simulates the effect of wind when the boat is close-hauled (sailing close to the wind direction). By looking from the stern the leech (the back edge) of the main sail is adjusted, using the main sheet and outhaul, to parallel the centre-line of the boat. The vang, which controls the vertical position of the boom, is then adjusted to tighten or loosen the upper part of the sail.

The leech of the club-footed jib (the fore-sail fitted with a boom, to allow tacking with a single sheet) is next set by adjusting the length of the main sheet and the outhaul, and the back stay is tensioned to control the leech of the sail, giving a constant “slot” clearance which parallels the leech with the mainsail.

By making further fore-and-aft adjustments to the mast foot position on the deck and the jib tack located at the bow, the tendency of the boat to head up into the wind or fall off as the wind speed changes (weather helm or lee helm) can be corrected. When properly trimmed the boat will sail in a straight line with little or no rudder adjustment. Rudder movement to control boat direction results in extra drag, slowing the boat down.

David then described how to adjust the sails to accommodate wind gusts, by flattening and easing the sails to reduce the heel and weather helm of the boat.

This tuning system can be used for sail trim on the other two classes of boats presented, with appropriate changes to the fittings on each boat.

David’s video illustrating this method can be seen on YouTube at https://www.youtube.com/watch?v=_Dm9GPXBDGk

Michael introduced the VICTORIA Class boat. The Victoria One Design is manufactured by the Thunder Tiger Model Company, and distributed world-wide. The kit’s low cost (about $110 for the kit, $200 to perhaps $400 ready-to- race), ease of assembly, and good sailing characteristics make it a great first yacht, while remaining fun to sail and race for old hands as well. It is easy to transport, fully rigged, in a small car. The one-design class rules are intended to ensure that all boats are kept as close as possible with regard to hull, deck, keel, rudder, displacement, and ballast, but in the case of the VICTORIA variations in rigging and sails are allowed.

VictoriaThe boat’s dimensions are;

Length Over All (LOA): 30.7 inches. Displacement: 4.5 lbs. Mast Height: 43 inches

The hull is made of ABS plastic, and is quite durable, capable of surviving virtually any mishap or collision. The kit also includes high quality aluminum spars, sails, and all necessary fittings. Sails may be of single or multi-panelled construction, while the sail material is left to the skipper’s discretion.  The usual two-channel radio is needed. Assembly is generally a weekend project.

The final boat which was presented by Michael is the DRAGONFORCE 65. This is a design based on the RG-65, an International development class with a 30 year history. (Development classes allow designers to take advantage of technological changes in hull, rig and sail materials and design, while maintaining basic parameters of the class, such as hull length, boat weight, etc.)

The DRAGONFORCE 65, developed in UK and imported from China, is the fastest growing class of sailboats in North America, with over 13,000 sold to date. It is a competition R/C boat recognized by the American Model Yachting Association, with well defined construction rules and R/C associations that are located worldwide. As a one-design class sailors sail against equal boats in every respect.

Dragon ForceThe boat’s dimensions are:

Length -25 7/8″ Beam – 4.57″ Mast Height – 36″ Total height 52.7″ Weight (without batteries) – 2.65lbs Sail Area – 344 sq. in.

The boat has an ABS hull, carbon fibre mast and booms, a profiled aluminium fin and molded plastic rudder. The single panel sails are made of Mylar, and while the boat is supplied with the “A” rig there are 2 smaller sail rigs, “B” and “C”, for sailing in increasing wind strengths. Whereas on many yachts the vang controls the boom by acting against the foot of the mast, the vang on the DRAGONFORCE acts downward from a point on the mast above the boom.

Available from Leading Edge Hobbies in Kingston at a price of about $270 (Yes!) it comes complete with pre-installed servos, pre-assembled booms, sails, fittings, and radio transmitter and receiver. All you need to do is assemble the spars, hang the sails, fit the keel and bulb, install the radio and install your own AA batteries – 4 for the transmitter, 4 for the receiver on the boat.

Further information on all these boats, including the class rules, can be obtained from the AMYA Website https://theamya.org/index.php. The photographs of the boats are taken from this and other boat-specific and club-related websites.

Our thanks go to David and Michael for their presentations, which were very helpful in comparing and contrasting three of the boats sailed and raced by the Sail Division. Boats designed to other class rules are also sailed by Members of the Sail Division. David and Michael extended an invitation to all members of MMM to visit the sailing ponds and join in the fun of sailing, both for pleasure and for competition. By calling ahead to Rick Levick, our Sail Captain, or to each of the Class division Captains – email contact details are on the MMM website – arrangements can be made to have a boat available for members to try their hand, with friendly assistance and advice on how to sail these boats.

So, come on out and get hooked!

Ray Peacock, Speaker Series

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