I have the same question. I've been looking for a small hammer
mill for making mesquite bean flour. The only hammer mill that I've
found for home/small farm use is the Novital, made in Italy, sold
in Australia for $570 delivered. On the internet you can find Amy
Smith's screenless hammer mill but I have yet to see a plan clear
enough to make one myself; emails to Smith have not been responded
to. I think her plan was a thesis at MIT so it might be possible
through interlibrary loan to get the thesis. Also, on Ebay there is
an offering of 25 patents for various kinds of mills--I've just
sent for the package so can't say where it includes a plan for a
small hammer mill.
If you run across any good plans, let me know. Good luck. Evan
Blythin blythin@hotmail.com
here is a site that has plans to build your own hammer mill if
you are a hands on type
http://www.makeyourownpellets.com/hammer-mills/hammer-mill-plans