Rotating-Tub Cam-Wheel Butter Worker: The Tub Turns Under a Cam Wheel, the Buttermilk Drains Through Its Centre

"The butter being placed in the tub or dish and the crank being turned it is passed many times in rapid succession under the beaters or cams of the beating wheel while the buttermilk escapes through the tube in the center."

Print the tub, the pinion, the beating wheel and the regulator. Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Build a pine base with a plank across its middle, bored for the tub's centre tube. Set four short dowel rollers round the hole so the tub rests on them and turns about the tube.

Over the tub fit a pine frame with bearers for a 10 mm square axle running across its centre. Fix the pinion on the axle where it meshes the teeth on the tub's rim, the beating wheel inside the tub, and a pine crank outside. Screw the regulator's handle to the frame by its slot so the blade stands between the centre tube and the wheel.

US 2,419 drawing sheet, public domain (expired patent).

Put 500 g of freshly churned butter in the tub and a bowl under the centre tube. Turn the crank steadily: the tub turns and the cams press the buttermilk out, which drains through the tube. Move the regulator to keep the butter under the wheel. Add cold water, work again and drain until it runs clear; work in a pinch of salt. Keep fingers clear of the pinion and the wheel.

**Seth Bishop** of Redding, Fairfield County, Connecticut, US 2,419, 8 January 1842. His tub was wider at the top, with a concave bottom and a gear near its top; the top frame was hinged on one side and hooked on the other. He claimed the regulator for forcing the butter under the beating wheel, with the whole as described. Our sizes and the teeth on the rim's top face are ours. FDM prints hold food in their layer lines, so wash well and replace when worn.