Endless-Chain Trailing-Paddle Churn: Paddles Hung on a Chain Drag Through the Cream

"The object of this invention is the churning of butter by agitation incidentally but more particularly by friction from the operation of the trailing paddles as attached to an endless chain in this invention, or to a single cylinder to which they might be attached and inclosed in a corresponding box."

Print four notched wheels (/uploads/blueprints/endless-chain-trailing-paddle-churn-notched-wheel.stl), 24 links (/uploads/blueprints/endless-chain-trailing-paddle-churn-link.stl) and 12 paddles (/uploads/blueprints/endless-chain-trailing-paddle-churn-paddle.stl). Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Use a food-grade container about 360 × 140 × 200 mm. Drill its sides for two 10 mm square hardwood shafts, 150 mm apart and 90 mm above the floor; one passes out through the side for the crank. Fix two wheels on each shaft, 88 mm apart, and seal the holes.

Cut twelve 104 mm rods of 4 mm steel. Join them with the links, two at each end, into an endless chain; thread a paddle on each rod by its eye. Lay the chain over the wheels, a rod in every notch, and glue a pine crank on the long shaft.

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 1.5 litres. Crank so the top of the chain moves away from the crank; the paddles trail through the cream. Time until the butter comes. Pour off the buttermilk, add cold water, churn a little and pour off again until it runs clear; work in a pinch of salt and weigh the butter.

**Harvey Brown** of New York, US 19,828, 6 April 1858. He claimed the arrangement of the trailing paddles, wheels and gearing. He also allowed a floating board on the cream to add friction on the paddles' return; we leave it out. His drawing gives no sizes; ours are ours. FDM prints hold food in their layer lines, so wash well and replace when worn.