gaffer
Guest
The concave will have a wear pattern. About six to ten inches from the seperator side there will be a dip in the first few threshing bars at the front of the concave. Put a straight edge across the first threshing bar and if there is more than 1_4 inch wear, it would be prudent to replace. The o.e.m. concave is a good replacement part. There is an extended 13 bar concave available through your dealer as well. This will involve the removal of the first cage panel behind the concave.It is unlikely that the concave is causing the cob breakage you describe. This is a basic trait of any rotary machine. The helicals are the spiral bars attached to the inside of the processor cage. If they are worn, the material is delayed in being discharged from the processor and this can result in excessive cob breakup.You can "piggyback" the existing worn helicals to improve discharge or install the o.e.m. transition kit if not already done. Do not piggyback on the belly of the seperator cage or you may end up with rotor loss.If the machine has an enclosed rotor with four solid discharge paddles, make sure the paddles are set on the "in" position. In the "out" position they will break and jam cob through the cage and put more work on the cleaning system than necessary.As to your question about lower speed rotor speed causing more cob breakage, I can't really answer other than saying sometimes yes, sometimes no. Spongy cob acts different than dry but generally, the manual is correct.