Screw-Turned Pendulum Dash Churn: The Swing Lifts the Dasher, a Screw Turns It as It Goes

"The dasher rod, E, is provided with a helical or screw thread, f, extending around it, and made to enter or work in a corresponding female screw, g, arranged in or applied to a cross bar, h, arranged between and fastened to the bars, b, b, and within the gate as shown in the drawings."

Print the sector rack (/uploads/blueprints/screw-turned-pendulum-dash-churn-sector-rack.stl), the pinion (/uploads/blueprints/screw-turned-pendulum-dash-churn-pinion.stl), the twisted rod standing up (/uploads/blueprints/screw-turned-pendulum-dash-churn-twisted-rod.stl), the screw plate (/uploads/blueprints/screw-turned-pendulum-dash-churn-screw-plate.stl) and the dasher (/uploads/blueprints/screw-turned-pendulum-dash-churn-dasher.stl). Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Build a standing pine frame of two A-frames about 600 mm high, joined at the top. Hang a pine swinging frame of two upright bars and a floor board from 10 mm rods through the A-frames, and stand a straight-sided food-grade container on its floor. Screw the sector to the top of one upright bar, centred on its rod.

Fix a cross bar between the upright bars with the screw plate over a hole, and a sliding pine gate above it. Glue 10 mm dowels into the twisted rod's ends, the lower one into the dasher, and pass the rod through the plate, its top turning freely in the gate. Mount the pinion on a 10 mm square rocker shaft in the standing frame, meshing the sector, and join an arm on it to the gate by a pine pitman.

US 16,193 drawing sheet, public domain (expired patent).

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 1.5 litres. Swing the frame steadily by its handle; the dasher rises, falls and turns. 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.

**Charles A. Shaw** of Biddeford, York County, Maine, US 16,193, 9 December 1856, signed 27 October 1856. He did not claim the up-and-down or the rotary motion from a pendulous frame each alone; he claimed the mechanism giving both at once. A twisted printed bar through a square hole stands in for his screw thread; pine, a container and printed parts for the rest. FDM prints hold food in their layer lines, so wash well and replace when worn.