# Tips on combining corn



## FarmerCline

I have taken a job combining some corn for a friend of mine. My combine came with a corn head but I have never used it. I have never combined corn and don't have much experience running a combine in general.....mostly all I have done is beans. Combined a few oats as well but had trouble finding a balance between keeping trash out of the bin and not throwing grain out the back. Just curious if there are any tips or tricks to combining corn. I want to do as good of a job as possible. My combine is a little JD 3300 with a 343 corn head.

Hayden


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## swmnhay

You need to open up the concaves so the cob goes threw without bustin it up.Slow the cylinder speed down enough so it doesn't crack the grain but fast enough to get off the cob.

Be nice if you had a book with all the settings in it.


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## stack em up

We used to run 1/2" on the concave, 250 cylinder speed, chaffer at 5/8" and shoe at 3/8 was a good starting point. This was for M2 and a K Gleaner but the principle is the same.


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## FarmerCline

I do have a manual with suggested settings. Compared to what stack said the manual has the cylinder speed much faster.....400-600 rpm. Guess I will start slower and increase speed if needed. Good info on sending the cobs through whole.....I wouldn't have known that. The biggest trouble I seem to have with this combine is getting the chaffer set. If I close it down I end up sending grain out the back but if I open it to where there isn't grain going out the back then I get a lot of trash in the bin.


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## haybaler101

Start with your book setting. If corn is dry, 400 rpm should be plenty. How fast is your fan running? You may not be getting enough air across your chaffer to "float" your trash.


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## swmnhay

If corn is wetter you have to run cylinder a little faster to get it off the cob.

Set the Chaffer 1/2 way between your 2 settings.Or shut them and throw handfull of corn on them and open slowly until the corn falls threw.

Not all combines run same RPM on cylinder,some combines are different diametor cylindor so that chages things.


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## FarmerCline

Not sure what the fan rpms are as it doesn't have a rpm gauge for the fan.....pretty much a wild guess as where to start and adjust a little at a time from there. Oats were what I was having the most trouble with and it almost seemed like when I turned the air down to try and not throw so many out the back it made it even worse. The corn I'm going to be harvesting is 15% moisture.....going to start first of the week.


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## r82230

If my memory serves me correctly corn and beans can take a lot more air than oats. Been awhile, but oats at 32-40# test weight, verses corn at 54+ pounds IMHO is one of the reasons for more air (fan). Your combine should have gates/doors or variable pulleys to adjust the fan speed or direction of air flow. As mention RPM, if my memory serves correctly, 250 (as stack said) rpm, was for corn and 700-850 beans/wheat/oats on a K (I don't remember the speeds on the JD95), so about 3 times faster (or 1/3 slower), could be a good starting point. Seem both of them had a different cleaning shoe, but they were 'older' machines. Large cob pieces is (IMHO) the key, to keeping the shoe clean. Just open the concave as far as possible, without leaving much unshelled corn on the cob. When you look behind the combine, make sure to back up the machine, to ensure the lost grain (kernels on the ground) are not coming from the head (verses just out the back).

Larry


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## swmnhay

FarmerCline said:


> Not sure what the fan rpms are as it doesn't have a rpm gauge for the fan.....pretty much a wild guess as where to start and adjust a little at a time from there. Oats were what I was having the most trouble with and it almost seemed like when I turned the air down to try and not throw so many out the back it made it even worse. The corn I'm going to be harvesting is 15% moisture.....going to start first of the week.


try the fan wide open,check for corn blowing over.Air is good it keeps the trash floating out the back.If corn going over open the chafer slightly.Find the sweet spot to far open and you will get cob pieces stuck in the chafer or in the grain tank.

It sounds like you are makeing your adjustments to far

Not enough air will cause trash to sit on chafer and grain to go out the back


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## GNA_farm

When making adjustments, only make 1 at a time and see how that affects the results, a few years ago when I started doing my own combining I got in to a rush sometimes and would make multiple adjustments so I never really knew what was doing the right thing, I slowed down and started trying one thing at a time and that is where I really learned how to fine tune my machine in particular to the crop I was harvesting. The manual is a great starting place (I usually start somewhere in the middle as others have said) but it takes a few acres and a lot of checking to figure out what does what in practice. I also put a lot of air on my corn and beans, have found that more seems to be better on my 660


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## barnrope

You got some great info. Post some pics of your 3300 in corn. There aren't many of those left in the Midwest.


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## stack em up

barnrope said:


> You got some great info. Post some pics of your 3300 in corn. There aren't many of those left in the Midwest.


Can't say I've ever seen a 3300. Mostly 6600s from that era around here.


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## swmnhay

stack em up said:


> Can't say I've ever seen a 3300. Mostly 6600s from that era around here.


Had a nieghbor with 3300 with 3 row head.Was a few 4400 but not many here.Actuallly in that era MF was the leader HERE.

The 6600's were called corn grinders back then.


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## stack em up

The guys that had Deere had 6600s, but Gleaner was king in our area. Had a great dealer in town, when they closed in 2000 lots of guys went Deere, but the die hards stayed Great Silver.


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## mlappin

You definitely want more air for beans/corn than you run on wheat.

On our Mf rotaries we turn the air all the way up, open the sieve about all the way open and jam it thru, if we get too many cobs then its time to either slow the rotor down or open the concave some more.


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## luke strawwalker

FarmerCline said:


> I do have a manual with suggested settings. Compared to what stack said the manual has the cylinder speed much faster.....400-600 rpm. Guess I will start slower and increase speed if needed. Good info on sending the cobs through whole.....I wouldn't have known that. The biggest trouble I seem to have with this combine is getting the chaffer set. If I close it down I end up sending grain out the back but if I open it to where there isn't grain going out the back then I get a lot of trash in the bin.


What's your air like??

Some combines have variable speed fans (like Deere and others, which use telescoping pulleys to vary the speed of the fan shaft versus the drive sheave), and some combines use shutters to restrict the amount of air going through the fan and into the cleaning shoe. Some combines also have an "airboard" that is adjustable for angle to direct most of the air to the front of the shoe, or more evenly spread further back across the chaffer and sieves.

On our old Ford 640 (Claas Senator) we used to run the air shutters wide open all the time. The fan speed was fixed to the main machine cross-shaft speed. On most Deeres, there's an adjustment to the pulley spread which sets the fan rpms and thus airflow to the shoe. Check your book. Most older combines are manually adjusted, by loosening bolts on one of the pulleys and turning it to make the belt ride higher or lower in the sheave, thus increasing or decreasing the speed of the belt, and therefore the amount of air delivered to the cleaning shoe. You want to check your book and make sure that the air is set to recommendations, at least to begin with. IMHO you can't hardly deliver too much air to the cleaning shoe-- we always ran the air wide open and then adjusted the chaffer and sieve by opening up until we didn't float any grain out the back off the chaffer, and opened the sieve until we weren't floating any grain into the returns elevator. We'd get a nice clean sample in the tank.

Another thing you can check is the condition of the fan belt driving the cleaning fan. If it gets glazed or is loose and slipping, it won't turn the fan fast enough to deliver enough air to the cleaning shoe. Another issue is, double check the airboard to see that it hasn't slipped out of position, or gotten turned and isn't allowing the maximum airflow to the shoe or is misdirecting the airflow. When my granddad quit farming sorghum in the early 80's, he was complaining that the combine was doing a terrible job of cleaning the grain, but he couldn't figure out why. Years later, when I started growing sorghum again, I started checking it out and found that a rubber flap "seal" that connected the stationary fan housing to the reciprocating cleaning shoe, had come loose and dropped down into the airflow channel, and was basically cutting the airflow from the fan into the shoe by at least half. No wonder it wasn't cleaning well! Once I fixed that, it was good as new.

SO, that'd be my first advice-- check the airflow of your cleaning fan to the shoe.

Later! OL J R


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## luke strawwalker

When you adjust a combine, start with the settings in the book. Starting in the center of the range of adjustments and go up and down from there as needed.

Make one adjustment at a time... and do them in order of the flow of the material through the combine-- IOW, set the header first to do a good job and get the basic ground speed set, then adjust the concave and cylinder speed-- if you're getting incomplete threshing (grain left on the cob or in the head) increase the cylinder speed or close up the concave a bit (increasing speed of the cylinder increases capacity, closing the concave decreases capacity slightly). If you're finding a lot of broken kernels and busted cobs or excess grinding of the straw, decrease the cylinder speed slightly or open up the concave clearance slightly. (Again, slowing the cylinder speed decreases throughput capacity slightly, and opening the concave increases it slightly). Be sure you check the returns auger to the cylinder, to make sure that any cracked grain isn't from excess returns being rethreshed, which usually results in cracked grain. Excess tailings is a problem with the cleaning shoe adjustment which will have to be addressed back there). If tailings return is not excessive, and threshing and separation of the grain is acceptable at the concave and cylinder, then go on to adjust the cleaning shoe. Start with air, which should always be at the top of the recommended range, if not at maximum. Same with the chaffer and sieve settings-- they should be at the maximum recommended opening clearance as a starting point. Inspect the grain coming in the tank-- if excessive trash is getting into the tank, increase the air or close the chaffer and sieve slightly. If the grain is acceptably clean, inspect the ground and chaff behind the combine. If excess grain is riding over the chaffer and sieve, open the chaffer and sieve slightly. If that doesn't fix the problem and you've got the chaffer and sieve wide open, start reducing the airflow. If you have excess tailings in the return elevator to the cylinder, then open the sieve more. If opening the sieve is not reducing the tailings, then start reducing the air. Inspect the tailings and see if they're caused by incomplete threshing of broken heads still containing grain (from underthreshing, increase cylinder speed or decrease concave clearance to compensate) or from overthreshing, (caused by excess cylinder speed or too tight a cylinder clearance) causing excess broken chaff, straw, and broken grain overloading the shoe. In some conditions it's possible to simply overload the cleaning shoe with too much material, slow down the ground speed to give the machine more time to process and separate the grain from the chaff and get the chaff out of the machine. It's a good idea (IMHO) to start with maximum air to the chaffer and maximum clearance on the chaffer and sieve, and then adjust them down to clean up the grain in the tank as much as possible without causing excess tailings returns or grain going over the back of the shoe and onto the ground.

You have to keep in mind how each adjustment you make will affect the machine downstream of that adjustment-- IOW, adjusting the cylinder speed or concave clearance will affect how much material is going onto the cleaning shoe, and what condition that material is in.

Best of luck! OL J R


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## FarmerCline

Started combining the corn today and it ended up being a lot wetter than was anticipated.....21-22% moisture. It's going to have to be dried but I was surprised the elevator even took it......can't imagine harvesting beans or small grains at that moisture but apparently it isn't that uncommon to harvest corn that wet?

I was surprised at how close I set the combine to correct before I even started picking. I almost had it just right but I did have to make a couple small adjustments. There were a few more cracked kernels that I liked so I opened up the concaves a couple rounds and that cured that but still seemed to get all of the kernels off the cob. There were also a few more little bits of cob in the grain than I liked so I closed up the sieve a little as I noticed a lot of little pieces of cob stuck in the sieves. I checked the tailings and there was almost nothing getting sent back through the combine. When I left the machine running and I jumped out real quick to check and see if any corn was going over the chaffer I didn't even noticed any corn going over or through the chaffer.......I guess it was getting separated before it got there? All in all in was very easy to get set. The day was going well until I got a flat drive tire on the combine.....I guess old tires and corn stalks aren't a good combination.....hope it can be repaired.


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## mlappin

Experts claim it should be picked before it's at the moisture, they claim that head loss, butt shelling etc etc costs more than drying wetter corn. Personally we really ain't making good time till its in the lower twenties, even 24% corn takes longer to unload out of the cart, out of the trucks and the dryer runs slower the wetter it gets, we don't like picking much under 20% either as you can see the head loss from the cab.


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## mlappin

FarmerCline said:


> There were also a few more little bits of cob in the grain than I liked so I closed up the sieve a little as I noticed a lot of little pieces of cob stuck in the sieves. I checked the tailings and there was almost nothing getting sent back through the combine. When I left the machine running and I jumped out real quick to check and see if any corn was going over the chaffer I didn't even noticed any corn going over or through the chaffer.......I guess it was getting separated before it got there? All in all in was very easy to get set. The day was going well until I got a flat drive tire on the combine.....I guess old tires and corn stalks aren't a good combination.....hope it can be repaired.


Stopping to check changes how the corn goes thru the sieves.

Usually we don't close the sieves for pieces of cob, instead open the concave more or slow down the rotor/cylinder as long as it continues to get all the kernels off the cob. On good solid ears our rotaries can be adjusted till all the kernels are off the cob and they come out in halves or quarters, sometimes even intact.


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## haybaler101

Purdue always said 25% was ideal moisture. Personally, I like to shell 17-19% corn. Flows good thru everything, shells off of the cob good with minimal rotor speed and head loss isn't bad but I run hydraulic deck plates and a case IH head. We have some BTO's that start at 30% and they lose so much out of the back of the combine that they do not need to plant cover crop.


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## FarmerCline

Picked corn most of the day today.....went pretty good again. The corn kernels seemed to be cracking a bit more today so I opened up the concave more but that didn't help much and I almost al the way open so I decreases the cylinder speed some and that significantly reduced the cracking. So far I like combining corn much better than beans.....almost fun. Got a couple pictures of the 3300 for those that wanting to see it.


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## FarmerCline

mlappin said:


> Experts claim it should be picked before it's at the moisture, they claim that head loss, butt shelling etc etc costs more than drying wetter corn. Personally we really ain't making good time till its in the lower twenties, even 24% corn takes longer to unload out of the cart, out of the trucks and the dryer runs slower the wetter it gets, we don't like picking much under 20% either as you can see the head loss from the cab.





mlappin said:


> Stopping to check changes how the corn goes thru the sieves.
> Usually we don't close the sieves for pieces of cob, instead open the concave more or slow down the rotor/cylinder as long as it continues to get all the kernels off the cob. On good solid ears our rotaries can be adjusted till all the kernels are off the cob and they come out in halves or quarters, sometimes even intact.


 Its costing my friend 50 cent a bushel to have the corn dried....seemed kind of costly to me. (Edit) now that I think about it I think that the 50 cents a bushel also included the weight loss once it's dried down.

I don't have another way to check without stopping while there is still some crop going through the combine and running around real quick to see what it's doing. Most of the cobs are coming out in half and a lot of mostly whole cobs there were just a few small pieces a little bigger than the corn that was getting in the bin with the grain and stuck in the sieve. Can't find hardly any grain going out the back.


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## Farmerbrown2

We had a GT batch drier growing up ,once corn got below 21% seemed to take same amount of time to dry.17%was just a pain would take forever didn't seem like corn would heat up and drive moisture off.


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## mlappin

farmerbrown said:


> We had a GT batch drier growing up ,once corn got below 21% seemed to take same amount of time to dry.17%was just a pain would take forever didn't seem like corn would heat up and drive moisture off.


Problem we have is we dump hot out of a continuous flow, at around 16-17% depending on which bin it will be cooled in, if it starts to get around 17% by time you warm the corn up much at all, you've already over dried it.


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## haybaler101

Anything under 19 here goes straight to the bin and air dried.


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## mlappin

Can't get away with that here, we've tried.


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## r82230

FarmerCline said:


> Its costing my friend 50 cent a bushel to have the corn dried....seemed kind of costly to me. (Edit) now that I think about it I think that the 50 cents a bushel also included the weight loss once it's dried down.
> 
> I don't have another way to check without stopping while there is still some crop going through the combine and running around real quick to see what it's doing. Most of the cobs are coming out in half and a lot of mostly whole cobs there were just a few small pieces a little bigger than the corn that was getting in the bin with the grain and stuck in the sieve. Can't find hardly any grain going out the back.


I don't remember the approximate amount of kernels (including those still attached to a cob), but seems like I wanted to stay south of 1-2 kernels per square foot total loss if possible. Two kernels was maybe one bushel acre loss??? IDK My point is it is easier to quantify number of kernels per square foot, than 'hardly any' (seems like you were suppose to measure 10 or 100 square foot area and how many kernels were counted in that area).

I do remember that you counted (and subtracted from total) any ears on the ground in front of combine (separate loss all together, not the combine's fault). I don't remember average kernels per ear either, but I read some where recently that ear is like 1/3 or 2/3s of a pound.

Maybe someone with a more current calculation will chime in, for a more complete instructions.

Larry


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## swmnhay

r82230 said:


> I don't remember the approximate amount of kernels (including those still attached to a cob), but seems like I wanted to stay south of 1-2 kernels per square foot total loss if possible. Two kernels was maybe one bushel acre loss??? IDK My point is it is easier to quantify number of kernels per square foot, than 'hardly any' (seems like you were suppose to measure 10 or 100 square foot area and how many kernels were counted in that area).
> 
> I do remember that you counted (and subtracted from total) any ears on the ground in front of combine (separate loss all together, not the combine's fault). I don't remember average kernels per ear either, but I read some where recently that ear is like 1/3 or 2/3s of a pound.
> 
> Maybe someone with a more current calculation will chime in, for a more complete instructions.
> 
> Larry


there is about 90,000 kernals in a bushel

43,560 sq ft in acre

2 kernals per sq ft = 1 bu per acre

There is 1.18% shrink per point of moisture when you dry it,although an elevator will take 1.4-1.5% per pt for a little extra in there pocket.

Drying charge is around .035 per point.

If you selling they dry down and shrink to 15-15.5%

If storeing down to 13-14%

Every elevator is a little bit different.


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## luke strawwalker

FarmerCline said:


> Picked corn most of the day today.....went pretty good again. The corn kernels seemed to be cracking a bit more today so I opened up the concave more but that didn't help much and I almost al the way open so I decreases the cylinder speed some and that significantly reduced the cracking. So far I like combining corn much better than beans.....almost fun. Got a couple pictures of the 3300 for those that wanting to see it.
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That's doing a fine job looking at what's in the tank...

Grain will crack easier the drier it gets... as harvest progresses and the grain gets drier, you have to slow the cylinder a bit to reduce cracking. Not a big deal.

You're ALWAYS gonna get SOME cob bits in the chaffer/sieve and in the tank. Can't be completely eliminated. So long as most of your cobs are coming out fairly whole (split in half either way is fine too), no (good) grain left on them, and the tank isn't making "white caps" of cob and crud sliding down against the walls, you're golden...

Later! OL J R


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## Bruce Hopf

GNA_farm said:


> When making adjustments, only make 1 at a time and see how that affects the results, a few years ago when I started doing my own combining I got in to a rush sometimes and would make multiple adjustments so I never really knew what was doing the right thing, I slowed down and started trying one thing at a time and that is where I really learned how to fine tune my machine in particular to the crop I was harvesting. The manual is a great starting place (I usually start somewhere in the middle as others have said) but it takes a few acres and a lot of checking to figure out what does what in practice. I also put a lot of air on my corn and beans, have found that more seems to be better on my 660


660 Case?


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## GNA_farm

Deere S660


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