Tips on Setting Your Combine for a High-Performance Harvest
In my line of work I get asked a lot of strange stuff, but I do think the strangest this year came a few days back, when one of my new bosses asked me to write up a “Tech Tip”.
In a few days I will start my 37th year in this John Deere store in Sterling, Colo. both as service tech and service manager, so I have indeed given my fair share of tech tips over the years. I would contend the best advice I ever gave anyone was to just stop now, and call the guy who knows. Most often as not that can save more time and grief, than doing it yourself.
I suspect however that isn’t what my bosses had in mind, so, what with millet harvest just around the corner, and King Corn, coming up soon, I decided to talk about combines.
Over the years, I have been asked many times: “How do I set my combine?” As I said, my standard answer is, “Call the man who knows.” (That would be your 21st Century Equipment service professional.) But I realize that is not always convenient, and it is a skill some want to master for themselves. So here’s my list of what to do and what look for…
Checking the multiple “machines” on your combine.
First thing: Determine ground speed. Not all operators are comfortable running at the same speed. This depends entirely on the operator—and it has an impact on how the combine performs.
Second: Remember that the machine you are setting is actually several machines in one. That’s why they call it a “combine”. It combines the job of several machines—cutting, feeding, threshing, separating, cleaning, grain handling and finally residue handling. All of this matters, because to set a combine correctly, you need to determine which “machine” isn’t operating up to par and needs adjusted. Then remember: Try to only adjust one thing at a time, so you can be sure what worked and what didn’t.
The best way to determine this is to do a power shutdown and get the machine in the field, full of material and running at the ground speed you have determined. Then, gently and in a hurry, at the same time: 1) pull the hydro to neutral; 2) stop the separator and the head; 3) idle down; 4) raise the head and back up about three feet; 5) and shut the engine down.
First look in front of the machine: Is there already grain on the ground before you get there as a result of wind shatter, critter damage, or disease ? If it’s on the ground now, we don’t have a chance of getting it the bin—so take that into account when you’re counting kernels on the ground behind the machine.
Next look where the head was just running: Do you see any head loss, cutter bar trouble, deck plate trouble, snapping roll trouble?
Then look in the feeder house: There should not be a lot of loose grain there; you don’t want your feeding machine doing the work of your threshing machine. Check for feeder house drum problems and feeder house conveyor chain trouble.
Next, get those shields off the side of the machine and look at the threshing machine. In the threshing elements and concaves (front part of the rotor) you should see grain still in its parent material—wheat in the heads, corn still on the cobs, etc.—at the very front of the machine, gradually coming off toward the last concave. There should be no grain left by the last concave.
Look next at the separator machine: All grain should be out of the rotor, before the last tines and separator grates. Cobs should be fairly intact and wheat straw not over-threshed.
Now look at the cleaning machine, chaffer, sieve, and fan. Are all the fingers in the elements straight, in line and all there? No big holes? Is the fan clear of any obstruction, grain, and debris and able to reach desired speed?
Now look at grain tank sample: Is it clean, not cracked? If there are kernels on the ground, is that grain loss truly from the machine?
Here comes the fun part: Given what you now know, determine which machine is at fault.
The #1 complaint is too much grain on the ground. You’re first inclination is to adjust the chaffer, adjust the sieve, adjust the fan, all at the same time, right? NO!
If the grain is still in the head or still on the cob, I guarantee it will come off when it goes through the discharge beater and/or the straw chopper. You will certainly have grain on the ground. The problem is with the THRESHING machine. Get the grain off the parent material first; THEN, make sure your cleaning machine can do its job.
The best description I ever heard came years back from an old custom cutter who told me, “You need to visualize the wheat going through that machine. Cut it, thresh it, ELEVATE it and get the grain to separate from the chaff and fall through it to the chaffer.” He told me you would almost always lose more wheat out of a machine with too little air than too much. Cut it, elevate it, and drive the combine under it.
The #2 biggest complaint is grain damage. The combine has to be over threshing, right? Adjust the concaves, adjust the rotor speed, all at the same time right? NO!
Maybe we should look at our tailings system; it is really only on the machine for small grains. The only thing we should ever see in the tailings is threshed heads, wheat, millet etc. If you’re finding good clean grain in the tailings, you’re most likely to damage it by running it through again. Get your tailings to a minimum, and open the sieves. Is the grain damage only being seen at the elevator? What about your grain handling system? Augers and troughs and housings? Sharp augers, worn out troughs and tubes can and will grind grain.
Finally, when your combine is happy, take a look at the job you’re doing handling that residue. Do you need to run that old chopper at high speed? Do you need those stationary knives fully engaged? If you can do a satisfactory job at a slower speed with less stationary knife engagement, you will save power, which saves fuel, which saves money.
Wow! That’s more words than I spoke, since I knowed ya! Hope it helps. Of course, you could’ve just followed my first advice: Call your local 21st Century Equipment service department and we’ll send one of the boys to help.
Keep your head down and aim low—they’re ridin’ shetlands!