The chakki is the hand quern, two stone discs with a wooden handle, turned by two women sitting facing each other, grinding the day's flour before light. The chakki songs are among the oldest recorded Punjabi women's verse and they are work songs with a beat set by the stone.
The madhani is the churn: a wooden staff with paddles, spun in a clay pot of curd by a rope pulled hand over hand, to raise butter and leave lassi.
Both are dawn objects and both appear constantly in the Sufi and folk repertoire, because the poets knew that a woman at a chakki at four in the morning is awake and can be sung to.
Electric flour mills reached most villages between the 1950s and 1970s. The chakki went first because grinding is heavy and nobody was sentimental about it.
The madhani survived longer and is still used in some households. Lassi made in one and lassi made in a mixer are not the same thing, which every Punjabi will tell you and which is also true.
The stones had to be dressed. A chakki wears smooth and stops cutting, and a man came round with a chisel to roughen the grinding faces again. That was a trade of its own and it is gone with the object it served.
Flour ground at hand speed and flour from a mill are not the same, because a stone turned slowly does not heat the grain and a fast steel mill does. That is why the word chakki still attaches to the electric flour mill in the bazaar, which grinds between stones slowly for exactly that reason.
What the two objects have in common is that both were worked in the dark before anybody else in the house was up, by women, and that both left it without anything being said about their going.