Two-Current Separator Rocking Churn: An Oval Cistern Split Round a Separator, the Currents Collide at Each Tip

"The operation being accomplished by oscillating the swing seat C, which gives to the cream cistern a successive tip motion, Fig. 1, red lines, thereby causing the cream to flow rapidly, being divided by the separator, into two separate currents in its passage, which come in contact at their terminus, alternately, whereby the cream receives a violent and peculiar action which causes a speedy union of the particles of butter into one mass."

Print the oval cistern (/uploads/blueprints/two-current-separator-rocking-churn-cistern.stl) and the lid with its separator (/uploads/blueprints/two-current-separator-rocking-churn-separator-lid.stl). The cistern needs a bed at least 210 mm long. Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Build a pine frame about 220 mm high and hang a pine seat between its uprights on a 10 mm rod, with two side strips that enter the cistern's guides. Hang a steel rod from the seat's middle with a stack of nuts as the pendulum weight.

Plug the lid's two ventilators and the cistern's outlet with corks.

US 18,165 drawing sheet, public domain (expired patent).

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 600 ml and fit the lid with its separator. Rock the seat end to end steadily; time until the butter comes. Draw off the buttermilk at the outlet. 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.

**Daniel E. True** of Lake Village, Belknap County, New Hampshire, US 18,165, 8 September 1857. His frame was 2 feet high. He wrote that grate and perforated dashers were not new, naming Enoch Thomas's and John McLaughlin's patents, and claimed the separator in rocking churns. A printed cistern at one third of his size, pine and nuts stand in for his. FDM prints hold food in their layer lines, so wash well and replace when worn.