A small model of a land yacht with adjustable sail, laser cut from 3.2 mm (1/8 inch) MDF. The dxf prints as a break out kit, for easy transportation before assembly. Made for a sailing themed day at Inspiria Science Center. There's an on board frame for a small heavy object, as the yacht will otherwise tip over quite easily. Coins or keys should do the trick. The sail can be adjusted by a small moveable block attached to the boom with a piece of string. The yacht will happily sail into the wind if the sail is trimmed correctly.
In addition to 3.2 mm (1/8 inch) MDF for the kit, you'll need some paper or fabric for the sail, glue, a few inches of string or wire, two or three bamboo barbecue skewers for mast, boom and axles and some rubber bands to line the wheels with for friction. I use the inner tubing from a mountain bicycle wheel cut across to appropriate width. This gives me the freedom to trim any excess rubber from the wheels if needed, and seems to work well. There's a comprehensive pictures only (Multilingual, see?) building instruction for the basic yacht with a jib in the file section, but part of the fun is experimenting with the rigging. Have fun!