RG 65 Racing Yacht

The RG 65 is a 650mm long remote controled international regatta sailing class. The classrules basicly limit the boat lenght, mast high and sail size . Though I started to design a super light hull. The shell is only 0.8mm thick enforced by 1mm by 1mm ribs.

The calculated mass is 95g. The wight of the hull is 120g (hurray). The average wight of the competitors is about 800g. The difference in the wetted area will hopefullymake the difference. :wink:

The openings are for the instalation of the RC stuff and will be sealed with oracover. In The round hole I will glue a film-dose -remeber these round boxes where the celluloid foto films came in. Through this I can recharge the batteries and seal it after charging.

The Green spot in the middle is some is some foam to fill a gab which faild printing.

here You see the edge of the shape accuracy


I would consider increasing the shell width to 1.5 or 2mm, and printing one section again. You may find the printed part to be more accurate as the thicker shell lets it keep its intended shape more easily (or not!).

Might be worth testing if the fitting accuracy is a problem.

Pretty cool! Where can we read about how you blew away the competition? :grin:

of course could I increase the thicknes, but then I would lose the advantage of ultra lightweight. Choosing 1,5 or 2 mm the hull gets as havy as a plywood/balsawood construction.

Due to my calculation 0,8 is stil to thick (lessen then 0,2mm is necessery) but then it got realy difficult to print. Never the less there is no tool you can build a part like this exapt of 3D printing. Even this (bloody) CAD Program -Inventor- is at its edge. To place these rips orthogonally to the skull is impossible, or may be I did not find out. If somebody knows how to … :slight_smile:

This is a test with 0,2mm shell and weighs unbelievably 12g (two and a half sheets of paper) but you see the holes and how the surface is bending.

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Hi Georg, I would recommend printing the thin surfaces not at such a shallow angle if possible. For example, if your parts are generally cube-like, it would be best to orient them so they are balanced on a corner. The peel cycle will then be less likely to distort the thin surface of the model.

This is a cool project and I’m looking forward to seeing more pictures!

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Why print the surfaces?? Print the stringers and bulkheads etc. Then use this http://www.protect-tapes.com/products/wing we use it on the wings for the AC boats…

It’s a heat shrink, tough as, great product. You can choose the thickness you want etc etc…

Good luck, looks like a fun project.


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Very nice project.

Regarding inventor, since it has problems with the thin shells it sounds like, have you thought of designing at a scale orpf 10 or 100x and then just scaling down the STL after exporting. You would scale it to 0.1 or 0.01, repair the shru Ken STL in Netfabb or let preform do it and then print.

I tried tis with Oracover, a foil used for planes and rc planes. Its heat activating glue and also heat shrinking.

To aviod this umbrella style after shrinking there is a layer of balsawood underneath. My strategie was this:

To make the holes printable :smile: I had to finning them what eat the saving.

That is an impressive model. Are you saying you printed that entire model and skinned it? If so do you have any picture of the model before you skinned it?

unfortunately the skinning did not work the way I hoped, so I throwed it away.

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