Case IH Combine Product Specialist Kevin Knapp discusses different types of rasp bars available to Case IH customers, depending on the crops being harvested.
Case IH pioneered rotor development back in the 1960’s. Since then, refinements, enhancements and improvements have led to the pinnacle in rotor performance, the AFX rotor. It features constant pitch impellers that draw the crop and air into the rotor. The AFX rotor can be configured many ways, adapting to both crop and threshing conditions with the use of standard non-spiked rasp bars, spiked rasp bars and straight separator bars. Competitive rotor and cage designs actually can reduce productivity and increase grain damage because of inefficient feeding and crop-control designs.
Case IH offers three different rasp bars:
- Non-Spiked Rasp Bar – used to thresh the crop. It is also used as a secondary separating element and provides positive crop movement. Available in Standard and Extended Wear.
- Spiked Rasp Bar– used as a primary threshing element with the additional functionality of aggressive combing of the crop mat while traveling through the rotor. This moves tough or green-stemmed crop through the combine. It will constantly comb the crop to prevent the crop from roping. These bars are typically bolted on the rear of the rotor for most crops, but can be bolted on the front for rice and other tough green-stemmed crops. The spiked rasp bar provides effective separation, ensuring that all crop material is torn apart as well as positively moved through the separation area. Spiked rasp bars are only available in extended wear and made of abrasion-resistant Chrome-Molybdenum cast iron.
- Straight Separator Bar– used as a primary separating element. This bar requires two rasp bar mounting pads to install on the rotor. It is primarily used in high yielding corn to increase separation. These bars are not recommended for very green crops, as they will consume power. The rotor will accept eight of these bars in the separation area. Apply only as required to address rotor grain loss.
The rotor itself is the same across the board, but it can be customized at the factory and configured differently for different crops and conditions. For example, the rice rotor will have all spikes, while small grain rotors won’t have any straight bars because they tend to consume power when it comes to crops like wheat. If you have a corn-bean rotor, it will have straight rows in addition to spikes. So basically, there are three different options, and they can come in Standard or Extended Wear.
Editor’s Note: Prior to becoming a Case IH combine specialist, Kevin Knapp spent six years as a combine test engineer for Case IH, traveling the world to test Case IH Axial-Flow combine technology in just about every imaginable crop and condition.