1. Sieve Settings for Corn
Bottom sieve: Run wide open. There is no part of the corn cob that needs re-threshed. Running wide open allows more air to reach the top sieve. If cobs appear in the tank, then the top sieve is too far open.
Top Sieve: Close to remove broken cobs and achieve the desired appearance in the grain tank sample.
2. Adjust Corn Head Angle
The right angle of attack improves the wear life and effectiveness of the stalk rolls. Park the combine on a level surface and lower the header until the lowest point of the row unit is approx. 2 inches above the ground. Place a protractor on the plates to measure the angle. Try to achieve 23-25 degrees in standing corn.
For standing corn: 23-25 degrees is the ideal angle of the corn head in standing corn. Within this range, the angular presentation of the stalk rolls enables the stalk to be pulled down vertically to become fully processed at the head. At the same time, this angle also allows the stalk to travel horizontally in the row unit so that the ear is separated from the stalk further into the row unit
To check the angle: park the combine on a level surface and lower the header until the lowest point of the row-unit is 2 inches above the ground. Place a protractor on the stripper plate and read the angle. We supply a magnetic protractor with all of our stalk roll kits so your investment will last as long as possible. Improperly angled heads will show premature wear in the stalk rolls at the very front.
For down corn: Flatten the corn head angle a few degrees in down corn conditions, making gravity less of an enemy. We recommend harvesting at approx. 20 degrees.
3. Set Corn Head Gathering Chain Timing
Begin calibration with an initial gathering chain speed of 55 RPM. If you are seeing butt shelling, slow down the corn head until it starts to bulldoze cornstalks then speed back up until bulldozing stops.
Properly setting corn head gathering chain speed helps prevent both the bulldozing and breaking of cornstalks. Improper gathering chain speeds can also contribute to kernel loss and increased trash intake.
Start with an initial gathering chain speed of 55 RPM for peak corn head performance. If butt shelling is a problem, slow down and calibrate the gathering chain speed until you observe stalks being pushed or ‘bulldozed’ forward, then speed up the chains until bulldozing stops.
4. Reduce Ear Slicing & Kernel Damage at the Cross Auger
Fine-tune your cross auger to prevent ear slicing and cracked grain. Adjust vertically to have 1 3/4 inches of clearance between flighting and the tray.
Properly setting your corn head’s cross auger is essential to prevent cracked grain, and ear slicing and for an efficient corn harvest. For optimum performance, adjust the cross auger vertically to have at least 1 3/4-inches of clearance between the flighting and tray at the tightest point to reduce ear slicing. Also, ensure it is adjusted rearward as far as possible.
5. Set Stripper Plate Gap
Pull a stalk from the field to test your stripper plate gap. Ensure the stripper plates are wider than the third cornstalk node from the brace root. Watch our video for full settings.
Properly setting your corn head’s stripper plate gap on each row unit has many benefits during corn harvest. Marion talks through the detailed stripper plate recommendations and testing procedures for the uninhibited entry of stalks into the corn head. The same measurement applies to both manual and hydraulic stripper plates.
Begin with normal settings of 1 1/8-inch gap at the front and 1 3/16-inch gap at the rear, then adjust accordingly to ensure plates are 1/16-inch wider than the diameter of the 3rd cornstalk node (the largest node) above the brace root. Ensure the stripper plate gap is centered over the stalk rolls for efficient feeding and reduced wear on the plates.
6. Set Feeder House Chain Speed
During your pre-harvest maintenance routine, adjust the feeder chain to maximum length and as close as possible to the cross auger. Run at maximum speed to reduce the potential of ears piling up during the handoff from the corn head to the feeder house.
Properly setting your combine’s feeder house chain is a must for a headache-free harvest. If the feeder house chain is improperly set, excessive material can become congested at the feeder house.
For maximum performance, ensure the feeder house chain is adjusted to maximum length and/or as close to the corn head’s cross auger as possible. Run it as fast as possible to reduce the chance for ears to pile up during the hand-off from the corn head to the feeder house.
7. Set Combine Rotor Speed
Increase your combine's rotor speed until you can see the first cracked kernel in the grain tank then reduce speed by 10RPM.
Properly setting the rotor speed on your combine is critical to an efficient corn harvest. Rotor speed can result in un-threshed ears or cracked grain in the tank, and we want to help you identify the various effects rotor speed has on performance. To properly adjust, increase rotor speed until cracked kernels appear in the grain tank, then slow down by 10 RPM. This adjustment applies to all colors of combines.
One way to identify if the rotor speed is too high is to evaluate the stream of grain traveling from the rubber shoot into the grain cart. If you see a small stream of ‘corn meal’ or fines in the sample, ease up on rotor speed.
8. Set Combine Fan Speed
Increase fan speed until the red chaff and pieces of broken leaves are no longer showing up in the grain tank.
Properly setting your combine’s fan speed is essential to getting a clean sample in the grain tank and for an efficient corn harvest. If you are experiencing heavy shell corn loss on the down-hill side of the combine, it is also likely related to fan speed.
Increase fan speed until the first cracked kernel appears in the grain tank, then slow down by 10 RPM.
9. Transport Vane Settings
Adjust transport vanes to the slow position (bottom of the vanes to the back of the combine). This will reduce kernel loss from the rotor area.
Properly setting your Case IH combine’s transport veins plate gap is critical to stopping rotor loss. To reduce rotor loss, adjust the transport vanes to the slow position. That means you will adjust the bottom of the transport vanes so they face rearward. This adjustment will help reduce kernel loss from the rotor area.
To adjust your Case IH’s combine vanes for soybeans (the opposite effect), click here.