Try slowing down your cly. speed. On corn I run my speed as slow as possable, where it will shell off of the cob and not crack any kernels, but our corn is dry here in the South, so it my be differant where your from. Good luck
You got to try prevent making the small pieces. Half height bars, remove half the bars on seperator side, rotor sweeps, different cylinder. I believe the general consensous hear has been to drop front of concave a couple marks wider the MID position. Good luck