Petticrows Model Dragon Project
The Petticrows model Dragon came as a result of a conversion that model boat expert, Dave Potter had with Tim Tavinor a few years ago. Coming from a competitive racing model yacht background, Dave suggested that Dragon owners could benefit from racing model Dragons and that might be a good thing for keeping members involved and supporting the growth of the Class.
Dave had borrowed an East Coast 12 (EC12, which is based on the ‘meter measurement rule’ as the Dragon) to allow Tim to visualise the size of model he was proposing, this being around 1.5m.
Most model yachts race (RG65, One Metre, Marblehead and 10 Rater) are designed around their own class rules and are not scaled down versions of the full-size classes. They have long fins and bulb ballast to maintain performance. The EC12 however is a class that has kept the traditional swept keel (no bulbs or wings) making it the ideal class to base the scale of a model Dragon. Tim wished to stay faithful to the Dragon hull shape, and as every boat would be identical then its performance (good or bad) would be the same.
Project “Petite Dragon” was created to make an out of the box radio-controlled sailing model for existing Dragon sailors or anyone interested in sailing an authentic Dragon model. To ensure a faithful reproduction the CAD data from a recently laser scanned Dragon hull was reduced to a 1:6 scale.A CNC plug of hull and deck were made, then the craftsmen at Petticrows did their work on a hull and deck mould.
Pic 1 – Dragon prototype in measuring tank
The first prototype hull was built with a flat deck with fabric deck patches. This allowed easy access into the hull to alter keel ballast displacement, radio fit and sheeting positions. It was decided to mould the hull to include the keel profile, then place a lead keel inside. Dave is a member of the Birkenhead Radio Sailing Club so had access to their measurement tank (pic 1) to check waterline with main keel and trimming ballast.
Pic 2 – Dragon prototype undergoing trials at West Kirby.
For the initial rig we choose to use a jib on a balanced boom similar to most racing model yacht classes.
A two channel radio control system allows the main and jib to be controlled simultaneously through a winch servo with a second servo controlling the rudder.
The mast is an alloy section with internal groove which allows the mainsail to be removed or changed.
Sails are made from 3 oz cloth to provide durability.
The rig can be dismantled with the mast splitting into two sections for storage.
A spinnaker option was contemplated but it was felt the complexity would be too much for most, even Dave, a radio sailor with 30 years’ experience!
Trials on West Kirby marine lake (pic 2) proved successful to proceed to next stage of addition of the moulded deck.
The revised prototype with new deck was displayed publicly for the first time at The Edinburgh Cup, (pic 3) The Dragon sailors welcomed the smaller addition to the class but felt a genoa was required to authenticate the Dragon look.
Pic 3 – Dragon prototype on display at The Edinburgh Cup in Cowes 2017
A sheeting system was developed to allow a genoa and mainsail to work off the same winch servo with the addition of a third servo to fine tune the mainsail after tacking or running downwind.
The deck mould was refined to incorporate the cuddy and cockpit sides. The deck to hull interface is identical to how Petticrows make the real thing. Two waterproof hatches inside the cockpit allow for access into the hull. One of the hatches has a recess for a radio pot with screw top lid for battery and receiver storage. A waterproof on/off switch is located behind the foredeck bulge.
Pic 4 –“Petite Dragon”
Pic 5 – “Petite Dragon” complete with genoa
It is hoped to have some mini regattas or match racing next year as the model would be suitable for sailing in the marinas.
We can now offer a “Petite Dragon” as a complete package literally out of the box. It will come in its own storage box complete with hull, rig, radio control and alloy stand.
For more details and information or to order a boat please contact our model boat expert Dave Potter firstname.lastname@example.org