Problem addressed/functional need
Small scale threshing and cleaning equipment is not easily available in the United States. Older combines have threshing cylinders that are often prone to plugging in weedy conditions - the axial flow design does not have "choke points" that are as vulnerable to plugging because the clearances and threshing area in general, is larger. This documentation is intended to spark new low cost approaches to small scale combine harvesting equipment. The other advantage is the potential for a smaller and lighter threshing and separating mechanism.
A cutter bar cuts the grain with a sicklebar mower which is fed by an auger to a feeder housing which carries the cut grain to the threshing chamber using serrated metal bars on rubber belting. The grain then enter the chamber where it is beaten by rotating bars and moved from one side of the chamber to the other by angled fins on the top of the chamber. The grain and smaller pieces of chaff fall through a partial cylindrical sieve set at a constant distance from the rotating bars. Weeds and larger straw are expelled at the end of the chamber. The grain and chaff falls to a tapered chamber to an auger which feeds it to an exit where the grain is moved by paddles to a cyclone separator with a manually damped vacuum applied to the top to extract chaff lighter than the grain and that is expelled through the vacuum fan. The grain movement from under the threshing chamber is also assisted by the vacuum generated through the vacuum generated on the cyclone. Grain is bagged and can then be run through a stationary seed cleaner before storage.
On similar larger machines, a more conventional sieve/chaffer fan separation process to either a bulk bin or manual bagger substitutes for the vacuum/cyclone seperation process.
How to use the tool
(add video of the functioning components and adjustments and modifications that may be possible)
Construction/how to build
Bill of materials for domestically available bearings, sprockets, chain, belts, belting, keyed stock,mower bars, steel gauge and dimension, fan and cyclone substitutes, commercially available sieves and screen specifications
(please post in forums if there is interest in an assembly/build post for small scale commercially available combines)
Open Source Ecology is working on a microcombine module. Link for full documentation and OSE project management http://opensourceecology.dozuki.com/c/Complete_Machine
Identify standard dimensions, clearances, ratios and commonly available bearings, sprockets, chain, belts, belting, keyed stock,mower bars, steel gauge and dimension, fan and cyclone substitutes, commercially available sieves and screen specifications
The equipment for study was made made available by http://eqmachine.com
Open Source Ecology started a google doc to analyze the functional components - the link is here https://docs.google.com/drawings/d/1wmSIky7O_-MBX4JiLSSU7mVcBhWYNqBCIq87WPnVL4o/edit