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Straight cutting 25' of invigor pod shatter, 7% moisture, 50 plus bushels, cutting on the ground as it is lodged badly. Fixed airfoil with front rows of cleaning seive removed as per harvest services recommendation and standard rotor with wide wire concaves (been running concaves for years with good results)

I cant get a decent sample. Full of trash. Tried rotor from 480-650, concaves 3-5.5, fan 750-950, cleaning seive 5-15mm. Ground speed 2.0 to 4.0 mph.

I didn't close the seive more as the airfoil needs to get air through to work? Or can I tighten it up as the front rows of louvers are gone and it will get air.

It is a MOG problem from cutting on the ground and straw is breaking up badly as it is bone dry but not sure how to deal with it.

Thanks
 

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Had this same problem. Just have to close the sieve and turn up the air until you get a clean sample. It will clean right up.
 

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I would cover the front 8-10 inches of the top sieve as you are loosing too much air from the front . Doo a quick kill and you will see that the air has blown a hole up front on the top sieve . By taping up or more permanently put a piece of tin on the front of the sieve will allow more air to lift the mog mass easier without cranking the wind .
 

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I would cover the front 8-10 inches of the top sieve as you are loosing too much air from the front . Doo a quick kill and you will see that the air has blown a hole up front on the top sieve . By taping up or more permanently put a piece of tin on the front of the sieve will allow more air to lift the mog mass easier without cranking the wind .
Thanks for the advice Marshall, but I already got it tightened up enough to call it good and finished the field (probably 5% dockage, mostly chaff and pods). I will keep your fix in mind for next time. But just wondering, between cutting the front of the cleaning seive out and blocking off the top seive is there an actual benefit to having a long seive machine with the inherent issues with bushings/cracks etc from the extra weight?
 

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Its hard to say, we had a short sieve 1680 running alongside a 1688 and 2188 for a few seasons and the 1680 had those flapper things on the rear of the bed augers and always made a nice even shoe load, so I never had to play with pinch/concave at all to get nice even distribution. If you can keep that shoe assembly loaded even I think they are fine, and that short shoe was always super easy to get a nice sample, sometimes too nice, and very low loss. Sieve bushings were also waaay cheaper than the big ones. On a rare occasion I think the long shoe helps especially when settings are close and one side of the shoe loads up a bit on a slight side hill or something, and as the power got bigger I think they are a bit more forgiving for setting. If the power is close and the threshing/flappers are all set up good I don't see much advantage if any for the long shoe, and that long shoe is definately more expensive to maintain and gave some problems on the earlier ones.(like you say cracks etc./quite more expensive parts)
 

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Ronski, i posted my thoughts a few weeks ago in SWFarm thread on modifying heritage combines. 2388 with airfoil and Harvest Services mods. Like you, i was keeping bottom sieve always open to 'get more air to air foil'. After endless problems in flax i finally closed sieve down to about 1/8"and everything improved, was able to lower fan speed if i wanted. For straight cutting mustard i run settings like you mentioned but will try tighter sieve next year.

So, as SWFarm says here, wind up fan and close bottom sieve. I understand you are done now but for next year toss out the idea of setting bottom sieve because of need to get air to air foil. I suspect closing bottom sieve will actually get you more air to the top.
 

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Thanks for the advice Marshall, but I already got it tightened up enough to call it good and finished the field (probably 5% dockage, mostly chaff and pods). I will keep your fix in mind for next time. But just wondering, between cutting the front of the cleaning seive out and blocking off the top seive is there an actual benefit to having a long seive machine with the inherent issues with bushings/cracks etc from the extra weight?
What we did with our machines years ago, was shortened the front of the bottom sieve. It was original sieves and welded back together and kept it back from the front of shoe. Opening up the front or the effective fan area allows the air to pass under the chaffer more effectively and float the material. It worked very well for us. We never combined canola but it worked well in all our cereal crops. Peas I am sure it really doesn't matter.

On an original 1460, we hung a skirt down from the alligator stairs and effectively forced the air to go under the sieve. Crops were poorer then and we had no issues. It also ended the eternal tailings cycle where the clean grain was blown back into tailings trough (we called the eternal cycle!) and then went out the rotor when the machine was running empty during corner turning.

On our last combines with the pendulum leveling system on the shoe, we have a lot of issues linked back to the "variable fan/throat area" which changes with the elevation compensation to maintain a level shoe. Going up hills you can plug the rethrashers easily due to this variance.

I guess this has been corrected somewhat with an "opti-clean" system where they reduce the fan speed going up hills and also maybe use a computer algorithim to open up the lower sieve to allow grain to fall through? - not sure how and what they do to compensate. Somehow the clean grain doesn't get blown back into the rethrasher trough is the ultimate goal!
 
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