Re: Kuchar Caoncave ?
We had them in the old 1480 and 1680. Used them in wheat, corn, milo, and sunflowers. I really liked them. We always got a clean sample, but I think the biggest plus is not having to change them between wheat and corn. There was one year where we had some really hard threshing wheat and had to install another cover plate over the second concave. It helped, but still wasn't as clean as we like. We fixed that by not planting that variety again.