Grain thresher 3D model is available on CGTrader for $10. Original author: jaketnet2012.
MAT (mat, filesize: 14 MB), PNG (PNG, filesize: 14 MB), JPG (JPG, filesize: 14 MB), MAX (Autodesk 3ds Max, filesize: 14 MB), SLDPRT (SolidWorks, filesize: 14 MB), FBX (Autodesk FBX, filesize: 14 MB)