Cogmoor

A hundred years ago a storm drowned the Tidewheel Tower of Harrowmouth, and its mechanism still lies in six flooded chambers under the harbour. You arrive as a journeyman engineer and cut the parts again. Each work order fixes what the tower allows: bearings set 120 mm apart in granite, an old 14.5 degree cutter, bronze teeth, a torque of 150 N·m at 10 rpm. You choose tooth counts, module and profile shift, and the pair turns on screen with true involute flanks, so undercut and pointed tips show in red long before you submit. Tap any figure and it opens into its formula with your own numbers put in. The work moves from spur pairs and bell trains to a tide rack, a planetary lantern drum, a worm that has to hold the harbour lock on its own and bevel wheels under the crown dial. Every order has three marks. Brass means it works. The Master's Mark usually asks for something smaller, stronger or with fewer teeth. Outside the orders there is a free bench, a ratio search through standard tooth counts, a loupe for a single tooth flank and a table that compares two saved designs figure by figure. A finished design can be struck onto a brass spec plate over a photo of your own and saved to Photos. Millimetres or inches, three animation speeds, no ads, no purchases, works offline.