Swing-Valve Gambrel Box Churn: A Pendulum Frame of Swinging Beaters in a Tapering Box

"When the frame is put in motion one half of the cream is forced up and against the end of the churn box in the shape of a wedge, and is then divided by the rod D. The lower part passes through upon the lower valve in an upward diagonal direction to the opposite end of the churn box at the same time the upper part passes downward in a diagonal direction to the same end that the other part did."

Print the box (/uploads/blueprints/swing-valve-gambrel-box-churn-box.stl) standing up, the dash frame (/uploads/blueprints/swing-valve-gambrel-box-churn-dash-frame.stl) flat, and two swing beaters (/uploads/blueprints/swing-valve-gambrel-box-churn-swing-beater.stl). Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Pin the two swing beaters in the frame's holes with 3 mm stainless rods so each swings freely; the dividing rod between them limits each to about an eighth of a circle. Hang the frame from a 4 mm rod through the box's pivot holes near the top.

Fix a pine lever to the frame's top, bent over the box to a hand staff. Cut a two-piece lid from thin plywood with a slot for the lever.

US 18,671 drawing sheet, public domain (expired patent).

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 350 ml, under half full. Stand the box in a tub of cold or warm water as he did, to set the temperature. Swing the frame steadily by the hand staff; 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.

**Lewis W. Beecher** of Avon, Livingston County, New York, US 18,671, 24 November 1857. He made the box of double tin and tempered it by standing it in a tub of hot or cold water. The specification leaves the lower beater's width blank and gives the upper one as 7 inches. He claimed the swing valves or beaters. A printed box at one third size stands in for his tin box. FDM prints hold food in their layer lines, so wash well and replace when worn.