Hello Mathias,
A few weeks ago I received the drawings for apple grinder. Making the drum was the hardest. But I have found a solution with a router and a jig.
I tested the apple grinder for the first time today and it works perfectly! Thanks for the drawings and the clear explanation on your website! Now waiting for the apple season ...
Building an apple grinder
Oleg's apple grinder
Bert's apple grinder
Apple grinder plans