We've built 2 rotors for R42_52 machines -- They're somewhat more rare in this area than the bigger machines. At this juncture haven't required any reverse bars. However, in consideration of the shorter separating length of the cage_grate, we installed sweep_agitators as opposing units -- 180 deg. across from each other, and both beginning at the R_H side of the separator grate. One operator removed his sweeps to see what would happen and experienced a mild rotor loss in soybeans along with some congestion at the discharge. Apparently the MOG wasn't breaking up as well for separation. We also built a rotor with 8 rows of bars in this manner several years ago, but added provision for short sweep additions at the discharge -- these were never used since we had eliminated the discharge paddles. Cleanliness of samples are much better with the 6 bar rotor, and the intake is much smoother with the wider spacing between rows of bars. I question the use of more knives in milo, etc. Seems to me that it would be better to break up clumps for separation than to chop them and increase shoe load.