Centrifugal casting is used for rotationally symmetrical workpieces. You need a mould in which the cavities have been milled or turned considering the shrinkage. For casting, the mould is being turned around its axis - sometimes more slowly, sometimes faster - and the liquid metal (I used the zinc alloy Zamak.) is poured into it. After some seconds the metal solidifies and you can stop the mould and open it. These parts do not need much finishing - just the drill holes - and of course, you have to remove the gate.
In the photos you can see the results of my first attempts, which were already quite successful. The motor is built in a small frame so that the liquid zinc does not splash around the room. A teflon funnel is built in the socket in the cover. So the mould can be filled safely.
With the help of this techniquethe rotors and various small levers can be cast true to the original.