calmer combine concaves case ih replacement upgrade
calmer concave kits for case ih combines


for John Deere Combines

New for delivery in 2023 & 2024 are Calmer’s first product for a part of the combine behind the corn head.  The culmination of 3 years of research in the shop and the field presents a solution for the most common problems operators of John Deere combines face in their day to day operation.  Marion took on the nagging and frequent problems farmer’s called him with in his role of customer service for the corn head products.  Facing the changing conditions of harvesting corn and soybeans around the world Marion dove into the threshing area with the same thought process of detailed examination followed by patient testing to find the results we all need.  As the descendant of a long line of entrepreneurs, Marion was born with the gift of finding tangible solutions to mechanical problems, and throughout his life, he has
spent thousands of hours discovering problems and inventing solutions to harvest corn and soybeans more efficiently. 

PROBLEM: Case IH Large Wire Concave in Position #1

What Causes Rotor Loss?

Large wire concaves have been used successfully for many years in older combines that were smaller and designed to handle lower corn yields than commonly grown today. In today’s high-yielding corn crops harvested in higher-moisture conditions newer combines have more horsepower and bigger appetites. The advancements have overwhelmed the capacity of the concave designs that worked sufficiently in the past. Large wire concave limitations retain shelled kernals in the rotor chamber long enough to be damaged. The low pass-through rate manifests the problems of rotor loss, broken cobs, and damaged grain in the sample.  If you own an older combine model, you will notice the capacity improve with Calmer Concaves as they increase the Concave Open Area in an optimized way saving investment dollars in newer equipment.

SOLUTION: Install Calmer MaxFlow Threshing Concave in the
Position #1

How Calmer MaxFlow Solves the Problem

The Calmer MaxFlow Performance Concave has a greater concave open area (COA) to quickly release shelled kernels from the rotor chamber onto the auger bed below. This larger COA reduces rotor loss and the chance of damaged grain. In combination with the larger COA, the Calmer MaxFlow Concave also has specially designed grain separation bars to easily remove kernels without damaging cobs. This allows for the entire cob to exit the rotor chamber without broken pieces falling into the cleaning area and traveling into the grain tank.

Results: LOWER rotor loss when harvesting

especially high moisture corn

PROBLEM: Broken or Splintered Cobs in the Grain Tank

What Causes Splintered Cobs?

Case IH large wire concaves used in positions #2 and #3 cause unnecessary cob
breakage. When cobs are broken or splintered into smaller pieces, they fall into the cleaning area and potentially end up in the grain tank.

splintered cobs in grain tank deere combine problem

SOLUTION: Install Calmer Enhanced Flow Round Bar Concaves in
Positions #2 and #3

How Calmer Enhanced Flow Round Bar Concave Solves the Problem

Calmer Enhanced Flow Round Bar Concaves are aggressive enough to finish removing all kernels from the cob while being gentle enough to reduce unnecessary cob breakage. This unique design allows green material to flow across the round bars without plugging. It also helps retain leaves, husks, and stalks long enough in the rotor area for an easy exit, reducing material other than grain (MOG) from falling into the cleaning chamber. The Calmer Enhanced Flow Round Bar Concave also accelerates the flow rate of shelled kernels falling through the concave into the auger bed when harvesting high-moisture
corn (above 25%), significantly reducing rotor loss.

Clean Threshing Results

You can expect fewer splintered cobs and a cleaner sample of shelled corn. Our after market concave upgrade also increases flow capacity and reduces kernel loss over the top sieve and out the back of the machine.

clean grain sample without shattered cobs deere combine

Un-threshed Pods in Sample, Split Soybeans in Sample, or Excessive Tailings

PROBLEM: No Cover Plates Under Concave in Position #1

When harvesting soybeans, most concaves used for corn harvest have openings too
large to retain pods or small grains long enough for them to thresh fully (see bottom left image). Instead, when they enter the threshing chamber, the unthreshed pods fall directly through these large openings onto the auger bed. These unthreshed pods then move into and overload the cleaning system and will need to be separated and sent back a second time to thresh. This process is commonly referred to as “tailings.” The tailings also contain clean threshed soybeans, which are unnecessarily rethreshed and can become split..  So if you are seeing pods next to split beans, and a heavy flow through your return, you can bet that you need a cover plate for the first position.

solve soybean pods in grain tank with cover plates
soybean pods fall through concaves without cover plates

SOLUTION: Install Calmer Pod Buster Cover Plates to Both Chambers Under the MaxFlow Concave in Position #1

How Calmer Pod Buster Cover Plates
Solve the Problem

The Calmer Pod Buster Cover Plates retain plant material to fill the large openings and create a mattress-type surface. The matte of plant material provides a gentle & natural rubbing action against each other as they travel over the horizontal grain separation bars while retaining the material in chamber for enough time to complete even the tough or green pods. Calmer Pod Buster Cover Plates also allow the operator to run the bottom sieve further open, pushing more air through the top sieve, reducing pod material in the tank. The use of natural plant materials reduces the chances of the rotor splitting soybeans over the longer duration in the chamber.

Pod Buster Results

Calmer Pod Buster Cover Plates allow for a
more complete thresh, reduces tailings, and
creates a cleaner grain sample.

calmer cover plates for deere combine concaves harvesting soybeans

PROBLEM: High Sieve Loss, Excessive Tailings, or Chaff and Hulls in the Grain Tank


Most concaves used for corn harvest have large openings to allow high volume of cornkernels to pass through into the auger bed or shaker pan. When harvesting soybeans,these large openings allow an unnecessary amount of MOG to pass through with the soybeans into the cleaning system. This excessive amount of MOG eventually overloads the chaffer and cleaning system and causes lightweight trash and hulls to end up in the grain sample. This flaw also causes soybeans and small grains to be walked out over the top sieve (chaffer) with the MOG and go onto the ground as sieve loss.

overloaded chaffer problems in deere combine harvesting soybeans

SOLUTION: Install Calmer ¼ Wrap MOG Limiting Concave Inserts into the Round Bar Concaves in Positions #2 and #3


Calmer ¼ Wrap MOG Limiting Concave Inserts reduce the size of the openings between bars by 42%, which limits the flow of excessive MOG leaving the rotor chamber and falling into the auger bed. Because the auger bed now contains a higher percentage of grain and a lower amount of MOG, less air will be required to separate the MOG from the grain on the top sieve. Consistent results in all soybean harvesting moisture and field conditions with lower sieve loss. Ultimately, fewer soybeans are walked out the back of the combine as sieve loss.  After installing the Calmer ¼ Wrap MOG Limiting Concave Inserts, you can expect a cleaner sample and lower sieve loss when harvesting soybeans and small grains backed up by our industry leading 100% Buy Back Guarantee.

¼ Less Work to Install

The Calmer Round Bar Inserts match a custom plate built into the mid-point of the concave’s arc which allows for one man install.  Easily installed mid-day, or removed quickly for a switch back to corn. The Calmer Enhanced Flow concaves have considered the needs of farmers who invented, tested, and proven their performance in hundreds of hours of lab and field testing.

Legal Notice

Calmer may, at any time and without prior notice, modify the content and operation of its website or this brochure, remove or modify the specific patents and/or patent list demonstrated in this brochure or on its website,

Calmer possesses a number of patent rights related to its operations, both foreign and domestic, including the following United States Patents: 11,058,058-Narrow Row Head Unit; 11,071,252-Stalk Roll with Multiple Flutes of Different Lengths; 10,785,911-Stalk Roll with Hybrid Flute Having A Sharp Edge and Two Blunt Edges; 10,674,665-Stalk Roll; 10,420,281-Narrow Row Head Unit; 10,045,483-Narrow Row Head Unit Ear Guide; 10,039,232-Stalk Roll; 9,554,511-Method and Apparatus for Stalk Shear Reduction; 9,560,804-Stalk Roll with Flutes Defining a Recess; 9,668,414-Stalk Roll with Series of Flutes Having Decreasing Lengths; 8,857,139-Method and Apparatus for Stalk Shear Reduction; 8,863,487-Narrow Row Head Unit; 8,464,505-Stalk Roll; 8,220,237-Stalk Roll; 8,171,708-Stripper Plate; 7,886,510-Stalk Roll; 7,373,767-Corn Head Row Unit; 7,104,038-Strategic Spatial Realignment for Attaching Cornheads to Combines; 5,704,202-Universal Corn Picking Row Unit; and D494,605-Low Profile Corn Head Row Unit Cover. Calmer also has patents pending pertaining to the threshing technology disclosed in this brochure. Any reference to a company that manufactures and sells combines, or to trademarks of the company are for informative purposes only. Calmer is not affiliated, associated, or otherwise related to any such company. Calmer possesses a number of trademarks. These trademarks are associated with Calmer and its products and are identified by the symbols ® or ™. © 2023 – Calmer Corn Heads, Inc., Lynn Center, Illinois

Calmer Limited Warranty

Calmer warrants our parts 100%. This warranty is good throughout the first season after purchase of the part. What this means is that if the part breaks within the first season of use, we will replace the part with a new one without charge to you. Calmer pays for the shipping both ways as well. In the alternative, if you wish, we will refund to you all of the money you paid to Calmer for the part. If the Calmer part does not work as you expected, we promise to work with you to adjust the settings and see if we can obtain satisfactory performance. In the end, if the Calmer part does not work on your farm to your complete satisfaction, we will refund your purchase price. Disclaimers: Calmer is not responsible for and does not warrant as to consequential damages or any other types of damages that may be claimed as a result of part breakage or unsatisfactory performance. In other words, except as stated herein, all other warranties or liabilities, expressed or implied, oral or statutory, including any warranty of merchantability or fitness for a particular purpose are expressly denied.