If you turn the crank, and all that happens is the Black Walnuts rotate in the Hopper,
then you need our Three very detailed and illustrated Modifications. Various Brands and models all suffer from this same design oversight. You should be able to hull a Black Walnut in about 30 seconds, on average. 

The only tool needed is a Metal File, or a grinder to remove material from the machine. This will in no way weaken the Antique, but it may detract from its value to an Antique Collector. You will also need about a Dollars' worth of very common hardware, which you may already have on hand.

Complete with a universal Template.