When I farmed in BC on a 126 acre homestead, we had a neighbour who sharecropped several neighbourhood farms in the area. He could work magic on his old John Deere combine and was a sight for 21st century eyes taking up the road with his big antique beauty. He took on about 60 acres of our land to grow wheat, spelt and oats. It worked out beautifully with our vegetable and pasturing rotations. Having a really handy guy with an old combine and all the other equipment necessary to grow grain is a rare honour; Not always easy to find.
If you are handy and live in an area where old agricultural equipment rots in fields or goes through auctions cheap, you could find an old combine like this farmer has.
But what are the other options?
The potential for intimate relationship with food is a thing seen clearly when a year's supply of grain is grown, harvested and cleaned by hand. This intimacy approaches oppressiveness when it is done for more than one's own bread...unless of course there are many of us doin it! (and then it becomes intimate again!)
Patience, perseverance and modest needs indicate a good scythe and a fan or very windy day. Dan Jason in Grain in the Garden (PDF) has an excellent essay on how to do just that.
To be self-sufficient in grain for a large family and their animals or a csa it would be good to look at equipment that is suited for that scale.
Small scale binders, threshers or combines are certainly not a mass produced commodity item and are difficult to find and usually jaw droppingly expensive.
Asia and eastern europe have produced some of these great little machines - some days I day dream of traveling and buying small farm equipment and then I realize ..we have to build them! What a time as the present for small scale local equipment fabrication; lets get to work manufacturing and importing implements for small and 2 wheel tractors (like the BCS) or small stationary units- recycled biodiesel, or ox, or horse - what ever each of our sustainable farming communities decide - and get the workshops humming in community colleges. To get the tools that we need (while we still can) maybe a multi-community effort to import together would be useful as well.
Here are a few links to combines and threshers for two wheel tractors or stand alone.
(A combine cuts and threshes in one operation. A thresher is fed (one would use a sythe or a sickle bar mower to cut the stalks).
Cicoria mobile thresher
thresher made from converted chipper shredder
Small scale corn thresher
Ferrari has here everything to fit a 2 wheel tractor but a combine. But in an article about small scale grains they mention a number of models.
Gene Logsdon's book Raising Small Grains is still arguably the bible on whole topic of grain growing - and its just back in print! http://www.chelseagreen.com/bookstore/item/smallscale_grain_raising