This contraption does three things.
1) Regulate the in-feed of cacao nibs inside mill. Just turning the motor on and filling in the hopper with nibs to capacity won’t work. It runs for few seconds, slows down, clogs and stops. It is actually a homogenizer designed for liquid materials. However, regulating the feed to some point make it usable for grinding cocoa nibs.
2) Prevents nibs from flying out of the hopper. The spiral drive just above the rotor was designed to suck liquid in. However, the material I am trying to grind is somewhat similar to corn grits. Some are sucked in successfully some are not and end jumping out. It is so frustrating to see the nibs I worked hard for are just flying off to ground.
3) Inject air inside hopper. It helps cool down the mill a bit and facilitate escape of evaporating acids. In absence, it condenses on sides of hopper and my diy contraption. It is so messy.
Still made of thin plywood, pvc pipe scrap, HDPE plastic sheet and screws. Revising as needed and plans on building a stainless steel version once finalized. It is not in the near future, I think.