Check Your Chaffer
Jul 26, 2018
I know you guys in wheat country are well into, or finished with harvest, but in the upper Midwest a lot of combines are coming out of storage as guys start to prepare for corn and soybean harvest. One thing guys in corn country need to check is the condition of their chaffer, aka, top sieve.
At our dealership we're seeing quite a few of the rear rows of louvers on chaffers that are bent forward, or missing. If they're bent forward, they catch and slow the movement of shucks, leaves and other material across the chaffer. If they're missing, it dumps cobs and extra junk on the lower sieve, which either passes it to the clean grain auger or into the tailing elevator. Either way, it's a problem that needs to be repaired before the combine goes to the field, and depending on the brand, model and size of the combine, it can get pricey to repair or replace chaffers and their louvers.
Once the louvers are repaired, what can you do to prevent a repeat of the problem? Because there are several potential causes of bent louvers, it's tough to prescribe absolute prevention, but one thing I know causes problems with chaffer louvers is related to modern chaffers that can be adjusted from the cab.
Let's say you're playing with chaffer and sieve settings, trying to clean up your grain tank while harvesting corn. At one point you crank the sieves fairly wide open. Inevitably, some cobs get caught in the louvers. If you then close the chaffer, those cobs twist, tweak and malform the louvers. If you're still not satisfied with the grain sample in the tank, and lean on the chaffer "close" button in the cab to force the sieves tighter, there's risk of doing even more damage to the louvers.
So my recommendation when harvesting corn is, whenever you're going to close the chaffer and sieve, stop the combine, get out of the cab, visually inspect the chaffer, and then manually dig out any cobs that are going to prevent the chaffer from closing.
I know, I know, I'm de-valuing the whole purpose of being able to adjust the sieves from the comfort of the cab. I'm just saying that there's more to operating a combine than sitting in the seat and pushing the auto-steer button.