Fan-Case Gathering-Valve Churn: Beaters Throw the Milk Into a Strainer, Then Gather the Floating Butter

"By my arrangement and by the form of the various parts as herein described and represented, I beat, cut and fan the milk and thereby produce butter in the shortest possible time and effect a most perfect separation of butter from the milk."

Print the fan case standing on its feet, the valve x, two gathering valves, the beaters, the conductor, the strainer, the water box, the pinion e and the wheel d. Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Use a container about 280 by 190 mm inside and 170 mm deep. Drill a 10.5 mm hole through one long side, 60 mm right of its middle and 85 mm above the floor, and a 6.5 mm hole 60 mm straight above it. Stand the fan case inside, its bearing in line with the hole. Cut a 10 mm dowel 210 mm long as the shaft, pass it through the container's side, the case and the beaters, and fix the beaters with an M3 screw drilled through.

Slide the valve x under the case's lower opening, its strip standing up beside the case. Drop the gathering valves into their slides on the case's sides, raised. Set the conductor over the upper opening, leading toward the strainer, and hang the strainer on the container's rim by its two hooks. Stand the water box on the floor at the other end.

Fix the pinion e on the shaft's outer end with an M3 screw. Put an M6 bolt through the upper hole as the wheel's stud, with washers, the wheel d on it meshing e, and a lock nut, loose enough to turn.

Fill the water box with warm or cold water as the cream needs and cork it. Pour 4 litres of heavy cream into the container and bring it to about 15 °C, checked with the thermometer. With the valve x open and the gathering valves up, turn the crank steadily and time it with the stopwatch: the cream is thrown up into the strainer and runs back. When it has broken, close x and lower the gathering valves: the butter floating on top runs in at the sides and is thrown into the strainer. Lift the strainer out, wash the butter in cold water until it runs clear, work in a pinch of salt with the spatula and weigh it.

**Andrew Ralston** of West Middletown, Washington County, Pennsylvania, US 21,575, 21 September 1858. His heater or cooler was tin or zinc, his fan case held together by small rods, his case shut with a lid. He claimed the openings o and v in the case's circular part, the valve x, the gathering valve h and the conductor u, arranged and combined. Our container, printed water box, sizes and gearing are ours, and we leave the lid off. FDM prints hold food in their layer lines, so wash well and replace when worn.