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Case IH 8230 Bottom Sieve lack of air flow.

12K views 23 replies 12 participants last post by  gary 
#1 ·
In some situations I have known people run the bottom sieve wider than the top sieve / chaffer sieve to allow for more air flow.
In Australia I understand all machines are supplied with the 1" 1/8" sieves
Has anyone tried the 1" 5/8" sieves to see if this would create more air flow?

Having flooded the fan housing before with the pre sieve set wide and the bottom sieve set to allow a clean smple, having more air flow would be desirable.

Having been on New Holland combines for many years they used to advise not to have more than 3mm difference between the top / bottom sieves. So to run the bottom sieve wider than the top sieve seems to mess with my thinking??

What is peoples thoughts and experience with this situation?
 
#3 ·
If by pre sieve you mean the bit of the sieve at the font of the top sieve, that should never be open very wide. At most the pre sieve should be open as wide as the size of the grain you are harvesting. In other words mostly closed. It's there for corn.

If you're talking about the top sieve (the chaffer), that's another story. In theory the 8230 sieves should be set identically to the way you set them in New Holland. The New Holland CR and the 8230 share the same cleaning system.

In my conditions, in wheat, we find the best results closing the top sieve down maybe to 10 and opening the bottom sieve, perhaps to 12. In my opinion the rethresher doesn't do much in small grains, so cleaning with the top sieve essentially bypasses it. If there are increased losses because of that, it means something needs to be changed in the rotor. Such as closing the concaves a bit, or speeding up the rotor some. Sieves actually work best when the material is suspended by air, with the grain just heavy enough to fall through it. Someone on the forum has a technique for tuning the air flow but I never quite figured out his procedure.

But most people run the sieves conventionally and seems like it works fine most of the time. I think you'll find on the 8230 if you start with the computer's default settings for your crop type, you'll have better luck than if you just try to set it according to your memory of other past machines. Can make changes from there of course, but it's a good starting point.
 
#4 ·
As torriem said, CR’s & Case share the same cleaning system (pre “Opticlean) albeit the fan, shoe drive are different & rethrasher is different.
In theory, the Case fan should be much better than the “old paddle fan” of a CR! Well, it’s not the fan that’s the problem.
I tried the inverse sieve settings & never got any satisfactory results.
To cut a long story short.
Make sure the concave is LEVEL & CENTRE first. Can’t stress how important this is to get this right. It’s in the operators manual & it’s 87mm for Level & 87mm for Centre .... AFX Large Tube rotor.
Make sure you have very good concaves in #1. I’ve found deep wire helicals work best in #1 for just about every crop. Cereals, canola, pulses etc.etc. These work.
If you haven’t yet done so after harvest, pull all the sieves out & clean the rails. Check all sieves are not worn out or broken any louvre wires. 1200-1400hrs is all you’ll get out of sieves.
Refit bottom sieves & make sure they open - side to side - evenly. Adjust as required, then calibrate them.
Fit top sieve rear curtains before refitting top sieves. Adjust sieves as required, then calibrate.
These curtains make a big difference to a machine that is set & calibrated correctly. The curtains make the air go through the sieves instead of going out any area that has the easiest exit.
You’ll find a much more “settled” & consistent machine once you done these things.
It’s no bullshit ..... they work ....... & it’s cheap to do.
Happy to discuss further if you want........ but all these other things MUST be done first. There’s no one “silver bullet” in making machines perform better. It’s incremental steps that get you there.
 

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#12 ·
I’ve run the bottom sieve wider than the top in corn quite regularly with success. No part of a corn kernel will ever need re thrashed, so there’s no reason for it to go back through the rotor. The bottom sieve can be opened for max air flow and the top used to clean. Small grains are a different story.....
 
#15 ·
Rear curtains

Here's the top sieve rear curtains installed. The video quality is poor ....... but I'm sure most will understand how they fit & how they work.
Once again I'll emphasise. These two bits of (durable/flexible) rubber DO NOT fix poor setup, worn out parts, wrong adjustment or wrong calibration of every other component, preceding!

 
#18 ·
We are cutting wheat right now, on the 8120 I have the top set at 14 and bottom 9 depending on the crop conditions and bin sample etc I may move them a number or two is all, pre sieve I have in the 3rd notch (small grain sieve there) I have the fan set at 1050, this is in heavy straw and 80 bu winter wheat. I did add the hard thresh covers to the rotor cage and it made a huge difference on getting my bin sample clean. Gap is 3 and rotor speed is 1000 ish. If you are still having trouble see if your dealer has a slide rule cheater, basically it has all the crops and you move it to what you are having an issue with and it tells you what to adjust to get your desired results, it has been a life saver at times because some of the changes aren’t what you would think to do.
 
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