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The Claas rotors are likley as long or longer than the Deere rotor that has to thresh and separate. The Claas rotors have a lot of space between the bottom of the rotor and the grates that kind of fluffs the material as it goes through. The smaller diameter and higher speed helps with the seperation.
 

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Combine rotors are far past the tumbling and fluffing stage, they are high speed centrifuges.

A 17.5” rotor turning 1200 RPM exerts a potential 357 G’s.

A 30” rotor turning 1000 RPM exerts 426 G’s.

The last Claas I looked at was just using a couple of feet on the rear of the rotors as transfer augars to get things back to the chopper, and it seems like people have to cover up much of the grate area to make it work it’s best in dry canola.

https://druckerdiagnostics.com/g-force-calculator/
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Claas rotors are for seperating only not threshing and seperating like deeres.
The Claas rotors are likley as long or longer than the Deere rotor that has to thresh and separate. The Claas rotors have a lot of space between the bottom of the rotor and the grates that kind of fluffs the material as it goes through. The smaller diameter and higher speed helps with the seperation.
Would you normally have 29% of the rotor grate area covered in a Claas harvesting canola? By the photo in the link it appeared like perhaps in that experiment, there isn’t even that much area left that might be open at times?

I thought I heard about Claas machines running fast cylinder speeds and tight concave clearances to make them awesome doing canola. No?
If you’re doing standing, green strawed, pod shatter resistant canola crop no covers, 100% open may be fine.
If you’re doing swathed, super dry seed and straw grossly over cured canola 80% cover may be needed.
I actually ran beside an S690 last fall in those exact conditions, my 780 ran twice the ground speed (a gallant effort to save seed on the S690) and 10% of the S690’s dockage not to mention the less losses.
Exceptional conditions? You wanta believe it but my combine has to work in all conditions.

Tight concaves and a cylinder speed just below cracking are more to prevent plugging than any threshing/separating reason.

Claas hybrid design overall chaffes the straw less, the same reason it leaves more whole straw, a rotarys multipule concave passes grinds it more and therefore leaves the chaffer to deal with more chaff with no way to directly control it.

meskies and SouthernSK posts also influence separation effects.

You can math yourself to death but in the end, it’s still a Deere.
 

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I agree on the math yourself to death Don. Don't take it personal Haystack, but typing on a forum, trying to compare two different makes of a combine is difficult. Just look how difficult it can be to compare two of the same! For example, often times you will hear of a farmer with two 9770's. One does a great job, the other loses grain and they can't figure out why, for whatever reason.

I recall many who have ran Deere and had rotor loss in corn figured out spacers under the rotor grates to move them away from the rotor tines helped a great deal with rotor loss (for some people). Just that one little change and so many had improved the machine. With that example, it is easy to see how comparing two completely different machines can be very hard to do on a forum. Comparing them in a field can also be difficult at times, but at least it is reality.
 

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I think covering some of the rotor opening area has some merit. While talking to the Sunnybrook rep at Ag Days, it seemed to me, they were tackling the problem of excess plant material from making it onto the cleaning shoe on the other end of the rotor.

Their concave for canola has a significant area totally blanked off which initiates the thrashing, followed by 50% of the concave area almost totally blanked off but with multiple diagonal thrashing bars, followed by a more traditional square bar and wire unit.

I was given the impression that they work extremely well at reducing losses.

His theory was that there must ordinarily be un-thrashed canola making it all the way through or most of the way through the rotor. I disagree, I believe their concave may actually be preventing the concave from overloading the shoe with chaff, and thereby allowing the airflow to work properly down on the cleaning sieve.

I hope some of these rotor coverage ideas work out. There are an awful lot of John Deere’s to scrap out there if they have to drop to the pace of a 40 year old Gleaner to get the canola losses under control.

https://www.thecombineforum.com/forums/attachment.php?attachmentid=149629&stc=1&d=1549330597
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That could be because the rotor has to turn too slow and the concave be set too wide in order to stop the shoe from overloading with chaff. It won’t get all of the seeds out the plants in almost all other crops with a canola setting. Why don’t people use faster rotor speeds and tighter settings? Likely because then it puts a way too much fine heavy chaff material onto the shoe. When the shoe gets overloaded, unlike some machines it’s shoe loss all gets discharged directly into the chopper.

I don’t trust electronic sensors that are just a strike sensor microphone when the seed and some of the chaff have similar velocities, especially when wholesale changes are made to the mechanical arrangements and velocity settings. That sensing part is still just a dumb machine with an adjustable noise filter. But I certainly agree that with traditional settings and mechanical pieces the loss will be moved around from one place or the other or compromised as a small combination of both.

There may not be a logical reason why the rotor isn’t capable of centrifuging that much seed out per minute if it wasn’t still thrashing it the full length of the rotor with too little speed or aggression and if a person could choose that more of the chaff would go out the end of the rotor instead.

Sunnybrook’s concave with far less chaff opening is the only thing I’ve heard of so far that ever made diddly squat difference.
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I agree with you guys. That’s why we remove the separator grates.
As in having wide-open space below the rotor? Doesn't everything just empty onto the sieve then?

Problem with larger rotors is that to generate the same centrifugal force you need a higher travel speed which results in grain damage on a sensitive crop. Also harder to get a seed to stop and make a 90ish degree turn and eject from the rotor when it is going faster and more in a straight line. The arc on a smaller rotor will have a lot more curve on it, easier to eject heavier material from the lighter stuff.

Unfortunately pretty much everything is working against squeezing more capacity out of existing single rotor combines, from a standpoint of basic physics.
 

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Not underneath, on the rear separator grates there is some covers on each side from factory. They are there to help balance shoe load etc. Our dealer recommended to take them out. Seems to help rotor loss in canola. Our sample never looks great though. But I’m happy with loss, and can live with some dockage I guess.
 

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Unfortunately pretty much everything is working against squeezing more capacity out of existing single rotor combines, from a standpoint of basic physics.
Nailed it.
I think the NH 10.9 has reached limits separating as well.
Claas has not. Stay tuned.
 

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The G forces employed are so astronomical in a combine rotor situation that I can’t see it’s variance being a major factor in the centrifuge separation. I suppose if it was cracking seeds the rotor speed could be trimmed down a touch and the concave tightened up, anything to arrest thrashing from occurring too late down the rotor stream for it to then still have the opportunity to be centrifuged out.

It looks like Sunnybrook’s concave design is not so much aimed at physical aggressiveness as it is toward material against material thrashing at the beginning of the entire process, while at the same time preventing almost all transfer to the shoe at that critical location.

The more I think about it the more I like the concept.
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I believe The Sunnybrook concave section elements are each half width of an ordinary standard concave segment as well. Other than the required blank style half width entry element, anywhere from 1, 3 or 5 of their material on material concave elements could fit into the traditional 3 concave positions? It also looks like maybe the left side concave mounting rail needs additional bolt holes drilled?

https://www.thecombineforum.com/forums/attachments/claas-lexion/149629d1549330597-sunnybrook-guts-into-new-lexion-0a1b181a-e2f6-40dc-9d5a-9fc90c68e556.png
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The G forces employed are so astronomical in a combine rotor situation that I can’t see it’s variance being a major factor in the centrifuge separation.
You would think so but I'm starting to feel otherwise. Case in point being the high speed rotors that Claas uses in the largest model(should be all models). For those unfamiliar pretty much the only situation where a Claas hybrid finds itself short of separation area is in cereal grains with higher straw load/tough conditions. In this situation rotor loss has been limiting factor with typical 1000RPM rotor speed and with the new 1250RPM speed available I can get at times a 20% increase in capacity at same loss levels. So the rotor speed can have a big effect but only if you can do it without damaging grain, which is where the smaller radius ejects more grain at same tip speed and you aren't dealing with sharp concave bars but instead smooth rotor grates to allow material to speed up even more. I can open or close a combination of rotor covers to allow more or less material out and prevent rotor loss/excess shoe loading. All this is controlled independently from the threshing operation done by cylinder. Others have said it already but I will echo that this is the KEY difference between the Claas hybrid design and ALL other combines.

Not to say that there can't be improvements made to other designs, but in all other cases changing one parameter ends up affecting others because threshing and separating are done in the same area by the same components.
 

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In this situation rotor loss has been limiting factor with typical 1000RPM rotor speed and with the new 1250RPM speed available I can get at times a 20% increase in capacity at same loss levels.

You could be right. But in all honesty I think you’re gaining capacity from increased tip speed accounting for 20% more swept area per minute.

No doubt the Class is a bigger machine overall including it’s swept area of rotor separation, which is why it works as a class 10 machine or perhaps even greater. I just feel that in this crop in particular John Deere is leaving too much on the table, as it’s a solid class 8 unit in most other crops.

I don’t think presently you can crack all of the canola in the tank with a John Deere to achieve a higher separation G force and end up having a clean field behind. It then just comes off the chaff overloaded shoe.
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