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Discussion Starter · #1 ·
Been running a small tube for 4 season, consistently struggling with rotor losses. We harvest low and take a bit more straw than normal. Doesn't seem to be as bad in heavier crops eg 4T/Ha+ not that we've grown them much since we bought the machine
Tried all sorts of module combinations it doesn't seem to be variety specific
Any ideas??
 

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You have to work with different concaves. It takes some time to get used to it, but then it's working great.
Worst case would be, that you have to reduce the engine load by around 10-15 %.....and the losses are getting way less, but i never had to do it that way.
 

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I've had a 7120 with a ST for best part of 3 summer harvests. I'm in an area that usually grows reasonably good crops and some would say bares no resemblance to where you are..... but I think my experience would be relevant to anyone harvesting brittle straw. The issue is not capacity of the rotor, but the ST is very aggressive on brittle/dry straw which gets broken up to short pieces making separation of grain more difficult = rotor loss even when machine should not being loaded up at all.

As conditions get tougher/ damper or generally in heavier straw the issue gets better. Towards the end of the third summer we changed back to AFX = dramatic improvement in straw quality in at least one job that previously was very bad for this problem = improved capacity in lighter/brittle conditions. I firmly believe that even if you don't give a stuff about straw it is still in our interest not to smash it to much in the rotor area because of this separation issue.
 

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What concaves do you recommend, JoRu?

In our conditions, we use normal fine wires in the front, coarse in the back, and losses for us seem the same with either normal or small tube rotors. We're talking 80-100 bu/ac wheat, fairly heavy, sometimes tough straw under irrigation.
 

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I don't have experience with irrigated wheat....it depends also on the variety. I was combining Pasteur Wheat 90-100 bu with
-) Hard Thresh Concaves from MAD
-) Small
-) Wide
-) Wide

...but like written before, in some conditions you might have to slow down.:rolleyes:
 

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Hi, do you use "straight separation bars" on the rotor? The small tube rotor does not have that mounted from factory. When havibg truble whit rotor losses I have started mounting two. It reduced the losses whit -50% in wheat. I now use 4 straight separation bars in the separation area and have almost now losses in wheat and barley at all.
 

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Note, if the losses from the rotor are threshed grain, the problem is the separation. The straight separation bars open up a hole in the straw after the bar and the grains can be separated and leave the rotor and go down to the sives.
If the losses are unthreshed grain you shuld modify the concaves. (I have almost newer found unthreshed rotor losses from a Axial-Flow in wheat) i would go for that you have separation losses. Try to mount 4 straight separation bars and a you will be happy
 

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The original poster was talking about 4t/ha being a heavy crop, and rotor losses being a problem in even lighter crops that have very dry straw judging by those yields so I doubt hard thresh kits and straight separator bars are going to solve any problems.

In light crops the issue is likely to be the ST rotor chopping the straw up too much making grain harder to separate from the chewed up straw....
 

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If I had a small tube rotor, I would put in 10 degree rasp bars (#84317777) over the concaves. Standard bars are 28 degrees and move material thru to fast. They will help greatly in reducing rotor loss in corn and wheat. They might take a little more power but they will stop grain loss. You also probably would not need hard thresh concaves as they thresh small grains very well. I always thought small tube rotors processed material a lot smoother then the AFX rotors. They also lessen wear on the rotor cone.
 
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