Double-Dasher Lever Churn: Swing One Lever, One Dasher Rises as the Other Falls

"At the end of the shaft (n, Fig. 4) which projects by the frame a long perpendicular lever is to be attached (as o, Fig. 3). This lever should be two feet long and at the lower end of it a pin or handle should be made as shown on the drawing, Fig. 3. To this pin or handle the power is applied and by swinging this lever (o, Fig. 3) as a pendulum the dashers (g g) are operated the one rising while the other is forced down."

Print two bent levers (/uploads/blueprints/double-dasher-lever-churn-bell-crank.stl), the centre lever (/uploads/blueprints/double-dasher-lever-churn-centre-lever.stl), the swing-lever socket (/uploads/blueprints/double-dasher-lever-churn-lever-socket.stl) and two dasher heads (/uploads/blueprints/double-dasher-lever-churn-dasher-head.stl). Print in PLA at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Make a pine frame about 400 mm wide and 320 mm high round a food-safe box about 250 × 150 mm, with caps along both sides at the top. Drill the caps for a 12 mm dowel centre shaft in the middle and two 6 mm rods 95 mm either side of it. Drill two holes in the box's lid under the dashers.

Hang a bent lever on each rod, horizontal arms pointing inward. Glue the centre lever and the swing-lever socket on the centre shaft, and a 330 mm pine swing lever with a dowel handle in the socket. Join the tops of the three upright arms with a pine bar on screws. Glue a dasher head on each of two 12 mm dowels and hang them from the horizontal arms on loose screws, through the lid.

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 700 ml and fit the lid. Swing the lever steadily by its handle; the dashers rise and fall in turn. 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.

**Enos Mitchell** of Pittston, Kennebec County, Maine, received US 2,102, dated 22 May 1841. His frame was "say four feet high, two feet wide, and one foot two inches deep, the posts and cross bars being three inches square"; a removable cross bar held the churn in place; to clean it the pins at the dashers' tops were taken out and the churn lifted from the frame. He claimed "the method of combining the two dashers of the churn by means of the bent levers h h and cross bar k, operated by the levers m and o attached to the shaft n." **Honest limits.** A food-safe box, printed levers and a tabletop frame stand in for his. FDM prints hold food in their layer lines, so wash well and replace when worn. Your times and weights are the result.