Calmer BT Chopper for John Deere - Model 40/90 Series - Corn Heads
Straight fluted stalk rolls and straight fluted knife rolls have too much overlap in the entry area. When rotating at normal speeds, these intermeshing flutes have no entry window preventing the corn stalk from engaging easily with the flutes. This slight hesitation gives the gathering chain lug an opportunity to break off the top portion of the plant (see lower left photo). This excessive overlap also causes stalk breakage at the nodes during lateral whip.
The Evidence Prior to Calmer Upgrade:
These overlapping flutes spin at 800 RPM’s creating a wall of rotating steel restricting entry of the corn stalk. By examining used straight fluted rolls and straight fluted knife rolls, the first 2-inches of the flutes are worn out. The balance of the flutes indicates minimal wear. Stripper plate wear also confirms this theory.
To demonstrate this stalk roll problem, I turned a food mixer on high and held the egg beaters so they were horizontal. Then I took a plastic straw and while holding the straw vertically, I tried to make the straw enter the beaters from the end, like a corn stalk entering a corn row unit. The straw bent over and never engaged with the overlapping flutes of the egg beaters. This is a great visual of what happens when we try to pick corn with straight fluted intermeshing stalk rolls (see photos below). This is dangerous!!! Do not try this at home.