Concavo-Convex Swing-Dasher Churn: One Lever Swings Two Curved, Pierced Double Dashers

"The cream is thus made to move backward and forward in the box and must in passing from one side to the other (a greater portion of it) pass through the holes in the dashers in a zigzag manner, breaking constantly on the sharp edges of the holes in the dasher which set at angles to each other…"

Print two bearers (/uploads/blueprints/concavo-convex-swing-dasher-churn-bearer.stl), two dashers (/uploads/blueprints/concavo-convex-swing-dasher-churn-dasher.stl) standing, two top pieces (/uploads/blueprints/concavo-convex-swing-dasher-churn-top-piece.stl), two side pieces (/uploads/blueprints/concavo-convex-swing-dasher-churn-side-piece.stl) and two bars (/uploads/blueprints/concavo-convex-swing-dasher-churn-bar-c.stl). The top pieces need a 220 mm print bed. Print in PETG at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Use a container about 280 by 190 mm inside and 170 mm deep. Drill 10.5 mm holes through both long sides, 70 mm each side of the middle and 140 mm above the floor. Screw a dasher onto each bearer's foot with two M3 screws, the arms pointing inward, and hang each bearer on a 10 mm dowel 212 mm long through the container's sides.

Bolt a side piece to each end of the container with two M4 screws. Lay the top pieces across the rim, the bearers through their slots, and push a 10 mm dowel 310 mm long through the side pieces over them as the bar g. Cut a pine upright 18 by 30 mm and 272 mm tall and bolt it to one end; pin a pine lever 18 mm square and 364 mm long to its top with an M6 screw. Join the lever's middle to each bearer's arm with a bar, M6 screws and lock nuts at every joint.

Pour in 2 litres of heavy cream at about 15 °C, checked with the thermometer, and set the top on. Work the lever up and down steadily and time it with the stopwatch: the dashers swing to and fro and the cream crosses through their holes. When the butter comes, lift the top and bearers out, pour off the buttermilk, wash the butter in cold water until it runs clear, work in a pinch of salt and weigh it.

**George K. Farrington** of Xenia, Greene County, Ohio, US 21,637, 28 September 1858, assigned to D. B. Tiffany of Xenia. His connecting bars were pinned to the lever's middle so they could follow the bearers' swing, and the top bore on the shafts and kept them in place. He claimed the double concavo-convex dashers, made and worked as described. Our container, sizes and printed parts are ours. FDM prints hold food in their layer lines, so wash well and replace when worn.