Draw-and-Throw Rotary Churn: Cream Drawn In at the End, Thrown Against Breakers

"When operated the dasher should be turned in the direction in which the inner edges of the paddles point. This will draw the milk and cream up through the orifice in the rim and throw it from between the paddles off tangentially on every side against the breakers."

Print the dasher disk-down (/uploads/blueprints/draw-and-throw-rotary-churn-dasher.stl): a 190 mm disk and rim joined by six paddles on tangents to the orifice; it needs a 200 mm bed. Print four breakers (/uploads/blueprints/draw-and-throw-rotary-churn-breaker.stl), the step (/uploads/blueprints/draw-and-throw-rotary-churn-step.stl) and the crank arm (/uploads/blueprints/draw-and-throw-rotary-churn-crank-arm.stl). Print in PLA at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Take a stock pot about 220 mm across. Bed the step in the centre of its floor and the four breakers upright round its wall, evenly spaced, in silicone, so the dasher clears them by 6–12 mm. Cut a plywood cover with a centre hole for the shaft.

Glue the dasher on a 10 mm square hardwood shaft so its rim runs at least 50 mm above the floor. Stand the shaft in the step, pass it through the cover, and glue the crank arm and a dowel handle on top.

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 1.5 litres, enough to cover the rim. Fit the cover and crank the way the paddles' inner edges point; 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.

**Samuel B. Howd** of Arcadia, Wayne County, New York, received US 4,887, dated 12 December 1846. His breakers rested on the bottom and might reach to the cover, screwed from outside or held by hoops so they could be removed for cleaning; "if greater velocity is required than can be given by the crank attached directly to the shaft ... a common spur wheel and pinion may be applied." He claimed the construction of a churn having a rotary dasher which draws the cream in at its end and expels it at its periphery against stationary breakers. **Honest limits.** A stock pot and printed parts stand in for his tub and wooden dasher. FDM prints hold food in their layer lines, so wash well and replace when worn. Your times and weights are the result.