Dehulling Buckwheat

[Foozle]

Hi! I grew and picked a few bushels of buckwheat for the first time this year and was wondering if anyone's had any luck dehulling by hand. I have a flour grinder that I'm trying and it works, to an extent. The trouble I'm mainly having is that many of the seeds are crumbly, so break apart when going through the grinder. Does anyone have good ideas on how to do this? Also, is the buckwheat supposed to be that delicate/crumbly or perhaps I have a bad variety or not the correct moisture content in my seeds?

Thanks!