Drum 600 650 ish 15 - 30 concave lots of wind wide as pos bottom sieve top so e to suit sample rotors flat high speed took 4 rota plates out the back through the inspection hole the easiest one to do I’m not sure if it helped or not. Just 3-4 kph seamd ok on losses. My concave has big gaps View attachment 831491
Do those not go below rotors in grates , we used to put those in for osr for what you say .No there rota cover plates to even up the material on the sieves for osr.