NANO 500 Class RC YACHT by ebdill

Last crawled date: 3 years ago

PLEASE NOTE
New files added 2-10-2017
IT WORKS!!!
PLAtypus (a good Aussie name!) was test sailed today 9.8.2017 in 5 - 12 km/hr variable breeze with #1 rig (80% fractional rig, main luff 850 mm, 200 mm foot on both sails) against a competitive RG65 and a DF65. Didn't lose out noticeably against the RG (apart from the stronger gusts) and equal or better than the DF. Well balanced and easily sailed in these conditions. As sailed and in pic, this yacht currently has a laminex fin modified from another small yacht. The boat was left in the sun and this caused some hollows to form near the stern of the hull (PLA is a thermoplastic material). Cover the hull if leaving in the sun!!! Print using a light colour so less heat is absorbed; could trial other materials such as PLA Plus which can be heat treated in an oven (80 deg. C for 45 mins) to improve heat resistance and mechanical properties.
Recent changes:
Uploaded pic of my nearly finished yacht 4/8 2017; added Delta bulb sections and Gooseneck/main boom files.
IMPORTANT: If you have downloaded the original files, note that the HULL, FIN, FIN CASE and MAST TUBE files have been replaced with ones to suit the latest hull design, and a DELTA BULB included which will float the hull to the designed all up weight (though with a larger surface area than a conventional bulb).
Apologies to those who have commenced printing with the original hull files which produced a hull which would not float to my designed weight of around 850g ready to sail.
If you have downloaded the hull files and have not commenced printing you can increase the volume slightly by scaling transversely say 110% and vertically 115% (hull around 104 mm wide). These figures will float the yacht at correct LWL for overall weight of around 850g.
I have now posted new hull files which will float the yacht to its designed waterline at an overall weight of around 850g. If you wish to carry more lead weight, scale the hull further in the Y (transverse) axis - scaling the Y axis by a further factor of around 117% will produce a hull of 120 mm width.
The fin/bulb weighed 510 g (only 60% ballast ratio) but a higher ballast ratio is desirable and could be achieved by using lighter booms and battery pack.
Note: The pic above does not show the recessed transom which I have redesigned for ease of fitting the rudder. Due to a number of requests for a hull design, I have posted my design for comment and printing. I have printed it, test floated and sailed it. Cut it into sections to suit your printer height, and print each section VERTICALLY (very important as it allows for no supports). You may need to design more ring frames for joining purposes depending on your printer (unless your printer can print 500 + mm high, then you can print in one piece). I printed in two sections, the stern at 270 mm long, and the bow 225 mm long allowing for a 5 mm bumper, and I have included the files for them as well as the joining ring frame I used. An extrusion width of 0.48 produces a 63g hull, 0.65 produces a 98g hull (as for my prototype). I printed the rear section on its transom, with 2 bottom layers, 0 top layers, 1 perimeter, using vase mode. The bow was printed on its large end with 0 bottom layers, 0 top layers, 1 perimeter, vase mode. Could also print with 0% infill not using vase mode. The bow section includes a dovetail to take slides for jib swivel and jib sheet. No raft or supports are needed. The fin box slot and deck opening are located for you, as are positions for conventional and swing rigs and the rudder tube (CAD and 3D printing gives perfect alignment !!). I have now included other fixtures such as fin box, jib slides, rudder, fin, hollow bulbs ( fill with lead shot/resin mix), curved boom, boom ends, boom band, rudder top spigot and bow plug. I have not included servo platforms, or battery or receiver boxes which you will have to determine sizes for. This should give those interested something to start printing.
Some more info can be found on Wollongong Model Yacht Club website (WMYC - see Brian's Stuff). Enjoy.