Combine Setting Playbook
Harvest optimization & performance manual. A professional framework for diagnosing grain loss, optimizing combine performance, and maximizing the benefits of Razors Edge Concaves — built around one foundational principle: a full combine is an efficient combine.
Introduction
The purpose of this playbook is to give Thunderstruck Ag team members, dealers, and operators a professional framework for diagnosing grain loss, optimizing combine performance, and maximizing the benefits of Razors Edge Concaves.
A full combine is an efficient combine.
When a combine is not operating at full and balanced capacity, you'll commonly see inconsistent material flow, cleaning-shoe overload, increased grain loss, inaccurate machine diagnostics, and reduced harvest efficiency. Proper setup begins with establishing full, even crop flow throughout the machine.
01Understanding Grain Loss
Grain loss should never be viewed as a single issue. Successful troubleshooting requires identifying where the loss is occurring before making adjustments.
02Eliminating False Loss Readings
Machine Leakage Inspection
Before making any combine adjustments, inspect the machine for leakage. Verify that all inspection doors are securely closed, seals are intact and functional, and there are no visible holes, cracks, or damaged panels. Then stop the machine, raise the header, and check directly beneath the combine — grain on the ground under the machine points to leakage.
If leakage exists, all other grain-loss data becomes unreliable until it's repaired.
Preharvest Loss Assessment
Inspect the standing crop before harvest for loose grain on the ground, naturally shattered crop, and crop damaged by weather or lodging. Preharvest loss must be accounted for separately and deducted from total measured loss.
Header Loss Assessment
Evaluate header performance for feeding or gathering issues. Common causes include improper reel or header speed, ground-speed mismatch, poor feeding performance, and improper header adjustments.
03Measuring True Grain Loss
Loss should always be physically verified before making adjustments. Use the drop-pan / field-verification method:
Verify loss physically first, use drop-pan results as your baseline, and calibrate the loss monitor afterward.
04Combine Adjustment Philosophy
All Razors Edge combine adjustments follow this order, without exception:
If the machine isn't full, increase ground speed first. If speed can't increase, tighten the concave 2 mm at a time. Ground speed is always the first adjustment when underloaded.
If unthreshed material is present, increase rotor speed in 50 RPM increments until threshing is complete. Then re-evaluate concave clearance, fan speed, and sieve settings — rotor changes affect total machine balance.
If the machine is full and threshing is complete but loss persists, decrease fan speed gradually, re-evaluating the sample and shoe performance after each change.
If grain damage is excessive, reduce rotor speed in 50 RPM increments until slight under-threshing appears, then increase the rotor back 50 RPM to set the optimal threshing threshold.
05Adjustment Increments
All adjustments should be made gradually and systematically.
| Setting | Standard Adjustment Increment |
|---|---|
| Ground Speed | Gradual increase |
| Concave | 2 mm |
| Rotor | 50 RPM |
| Fan | 50 RPM |
06Power Shutdown Procedure
A power shutdown freezes crop flow inside the machine under load — the most accurate way to identify where grain loss is occurring (rotor vs cleaning shoe, material-flow issues, separation efficiency).
Only experienced operators should perform this. The machine will stop full of crop — wait for all moving parts to stop completely and remove the key before inspecting.
Harvest normally into a representative area at your target throughput. Ensure the rotor is fully loaded, loss is running flat/minimal, and the machine is at steady state. Don't test in light crop.
Bring the engine to idle quickly — do NOT idle down or unload gradually; you want crop still moving through. At the same time, disengage the header and separator (kill switches) and pull the hydrostatic lever to neutral.
Rotor/concave: grain still in pods = rotor loss (under-threshing); over-threshed/damaged = too aggressive. Transition area: check for material backing up or uneven distribution. Top sieve: grain riding over = sieve too open or too much load. Tailings: heavy returns = incomplete threshing or poor separation.
OEM Inspection Guidelines
John Deere
- Rotor / concave area
- Cleaning shoe
- Grain tank sample
Case IH
- Front rotor (threshing)
- Rear rotor (separation)
- Grain tank sample
New Holland
- Rotor balance L-to-R
- Feeding distribution
- Grain tank sample
Fendt IDEAL
- Separation zone
- Flow path through machine
- Grain tank sample
07Power Shutdown Interpretation Guide
| Finding | Likely Cause | Action |
|---|---|---|
| Grain is STILL in pods | Rotor loss | Increase rotor speed · close concave slightly |
| Grain threshed but going over sieves | Sieve loss | Increase fan · adjust sieve settings · possibly reduce load |
| Material overloaded everywhere | Capacity issue | Slow down OR open concave / improve flow |
08Sieve Setup Procedure
An active crop will thresh and separate. A lazy crop will go over the back.
Tightening sieves excessively restricts cleaning capacity by restricting airflow, increases the tailings load, and creates false shoe overload.
09The Razors Edge Advantage
Razors Edge Concaves are engineered to deliver:
Operator Mindset
Incorrect Philosophy
- Slow ground speed
- Tight settings
- Restrictive crop flow
Correct Philosophy
- Full machine load
- Balanced crop flow
- Open, active, efficient separation
10Complete Troubleshooting Flow
If grain loss occurs, work the flow in order:
- Inspect for leakage
- Verify preharvest / header loss
- Confirm the machine is full
- Evaluate threshing performance
- Evaluate cleaning-shoe performance
- Perform a power shutdown if unresolved
- Verify findings with a drop pan
Final Operating Principles
Don't
- Don't guess
- Don't chase settings randomly
- Don't rely solely on monitors
Always
- Diagnose first
- Adjust second
- Verify results
Flow-Based Starting Settings
Starting points for Razors Edge Concaves by crop. Begin here, then dial in using the sequence above and verify with a drop pan. (Concave in mm; rotor & fan in RPM.)
| Crop | Concave | Rotor | Fan | Chaffer | Sieve |
|---|---|---|---|---|---|
| Soybeans | 24 | 450 | 1000 | 16 | 8 |
| Corn | 30 | 300 | 1000 | 20 | 12 |
| Canola | 24 | 450 | 1000 | 16 | 8 |
| Wheat / Durum | 12 | 800 | 1100 | 16 | 6 |
| Barley / Oats | 18 | 550 | 1000 | 18 | 8 |
| Peas / Lentils | 28 | 350 | 1000 | 20 | 8 |
| Edible / Seed Beans | 28 | 300 | 1100 | 18 | 8 |
Record your own best results on the printable Settings Card →
Quick Reference Cab Card
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