In the model, the main sails turned continuously, but the fantail operated on an intermittent reversing cycle, slowly slewing the cap and sails in alternating direction. The reversing phases were unequal, so the cap rotated through 360 degrees over the course of time.
The "Patent" sails intermittently opened and closed. As they did, the
striking lever at the back rose and fell together with its pendant chain and weight.
Inside the cap, the co-axial windshaft, built up from socket couplings and a sleeve piece, was driven by a 133t gear wheel and ratchet mechanism that allowed the shaft and sails to freewheel. Two large eccentrics pushed and pulled the striking rod inside the windshaft to operate the "spider" on the front end of the windshaft, which operated linkages to open and close the sail flaps. A small eccentric worked the striking lever. Behind them, a short shaft drove the fantail and slewing pinion.
The cap rested on a built-up roller bearing. The slewing pinion (under the rear overhang of the cap) was a built-up "peg" gear, which engaged with protruding bolt heads around the tower-top perimeter.
Builder's comment: To use an odd-ball Meccano part for its intended purpose is always satisfying, but to use a 20 gram weight, spoked wheels AND loaded sacks was serendipity.