Combines Why wont 860 cleanIJ

[Mav]

If the chaff were loose (not attached to the seed),then I would think one of the following would cause the problem: 1) low Airflow Something may be out of adjustment or there is something damping the air and preventing it from blowing the chaff out of the combine. 2) Something Causing The Chaff To Have Trouble Exiting The Combine For example, we run a chaff spreader and put some curved plastic (cut up five-gallon buckets) on the pan to help funnel the chaff into the chaff spreader. The plastic has a little too much curve so we have to use wire to flatten it out (pull it down). Sometimes the wire breaks allowing edge of the plastic bucket to reach up higher than the level of the sieve. Anyway, this inhibits the material from moving off the sieves (the material catches the edge of the plastic). Also, when there is too much curve in the plastic funnels, it bottlenecks the chaff from flowing out of the combine. I can usually tell when the wire breaks because the amount of chaff coming into the tank will increase instantly and significantly. Hope this helps.

 

[otteb]

How would I check to see the true fan speedIJ The other thing I don't get is if the fan speed in too slow then how can I be blowing clean grain overIJ The fan adjustments are all set by the book. The fan is basically running wide open. Can the sieves be worn so badly that the air flow over them is ineffecient and erraticIJ Could that be a problem like you describedIJ The machine has about 3000 hrs. on it. We don't have a chaff spreader so I can't think of anything impeding the flow of chaff from exiting the machine. Thanks for the thoughts! Much appreciated.

 

[Cookie_Jar]

Check the windboards that control the fan's air distribution in the fan's throat. If they are aimed too high, they will create a vacuum behind, which will suck the chaff down through the sieves. If they are aimed too far back, they will suck the chaff down just ahead of where the air flows from the bottom of the deflector. It's best to have them in the neutral position, where they don't deflect the air at all, or as Ray Stueckle recommended, throw the air deflectors out so they won't cause you trouble.

 

[swtvid]

The way I have seen grain out the back when there is not enough air and the grain stays in the chaff and sluff over the back. There are tach to check the speed with, link below sail then or barrow one. On our 850 I put the speed sender that is on newer one, wire inplace of feeder beater sender with a swicth to selected betwen the 2. Dee

 

[Mav]

I agree with swtvid. I too think that low airflow inhibits separating the grain with the mixed chaff. Also (this is probably not your problem, but it is worth mentioning),make sure that you are not running your sieves too tight. I know it seems backward, but if you pinch your sieves down too tight it will want to restrict the airflow.

 

[otteb]

Cookie. Can you be more specific about the "windboard" and its settingIJ Do you mean the wind deflectorIJ The book says to have the adjustment handle all the way down against the frame. Is that too much. Please advise. Thanks_

 

[cookie_jar]

Yes, my term windboard refers to the wind deflector. I have found the wind deflectors to be a significant source of trouble, resulting in dirty grain in the tank. I've found them a pain in my 80SP, my 510s and now my 750. The best explanation of the problem I've found is in the late Ray Stueckle's books on Combine settings for better Harvesting. He explains that a deflector acts similar to an airplane wing. The plane's wings hold the plane up by means of the vacuum created on the top surface of the wing which is deflecting the airflow. If you deflect the air in your combine, you also create a vacuum which will suck chaff through your sieves. It's as simple as that. The only position of a deflector that will not create a vacuum is if it is not defecting any air. You can guarantee no defection by simply removing the deflector. Some features are worse than useless. Think of Microsoft.

 

[cookie_jar]

If you're really keen on studying the wind in your combine, attach a 4" length of knitting wool to the end of a coat-hanger, and probe around in the airflow. You'll see the direction of the flow, as well as any turbulent and reverse flow that takes place. Sailors use this technique by attaching wool tufts to their sails. When the smooth flow is messed up, they adjust the sails.