Combines Bottom Sieve

I have run a 1460 and 1660 with about 5 rows of fingers out, also many of my customers have also taken them out with good results. When you take a used lower sieve out you will see that the front about 10" is not being used. Don't take out to many because you can't put them back.

On the Gleaner combine talk show they show this in the modifications,Pictures too. But they go one step farther by installing an adjustment lever for the front rows of the sieve. It's a good idea.

I like the idea of the adjustment lever.

Hello guys. My English is not so good so i am not sure that i understand you correctly. Do you want the front of the buttom sieve to be vide open all the time and then be able to regulate the backIJ will this be good in all kinds of crops.(how about small oilseeds) Thanks Mads

If you open up the front of the lower sieve, there will be a huge air blast coming through that section. It will actually make the air less even than before, and have more of a dead spot at the rear of the chaffer. In my opinion, the best solution is to deflect the air rearward and then crank up the volume to keep all light material suspended above the chaffer, so that the lower sieve only has to deal with grain and heavy, unthreshed crop. We have had great luck with this device.

Is the Hilco Fan Kit worth the effort,or should I invest in a new style fanIJ

That makes more sense to me. Thanks Mads

We put the new fan in our 1680. I wouldn't waste my money, the Hilco Kit looks more attractive to me.

The faster you get the light chaff suspended, the more open area for grain to fall through. The chaffer needs to seperate by air, and the bottom needs to seperate size. With the bottom sieve ten to twelve inches in front of the chaffer, it grabs a huge amount of air making it do the same job as the chaffer. When you close the bottom sieve, you cut the air off to the chaffer, making the chaffer seperate like a straw walker. This allows light thrash that air should have removed, make it to the bottom sieve, overloading it and the return. In corn it didn't make a big differance if at all. In milo and wheat, it makes a very noticeable differance. In pearl millet there is no comparison. Millet is a small seed and has a very high fodder to grain ratio, and the fodder is heavy, making it difficult to keep the fodder off of the bottom sieve. It is easier to get the seperation process started when the materail is coming off of the fingers to the chaffer. Once you get the trash lifted with air, it dose not take much air to keep it lifted and moving out of the back of the machine. I now run the long finger chaffer (corn) chaffer in all crops including millet, with excellent results. I did notice that the new Air Jet chaffer uses a wide open setting on the bottom sieve. My thought is to not starve the chaffer for air. I do like the looks of the Air Jet chaffer if it doesn't plug with stalks like that peterson did.

The standard setup doesn't have any problem getting the material suspended quickly. In fact, the vertical air blast is so hard at the front of the chaffer that small grain pelts the top of the machine. The whole problem is the lack of air at the rear of the chaffer. That is where the light material falls through because the air is not sufficient to keep it suspended. If your modification allows the back of the chaffer to get good air flow, then it will make a huge difference, which I think is what you have noticed. If you have time, tie some ribbons along the entire length of the chaffer to determine how even the air flow really is. The advantage of the fan deflector is even air flow front-to-rear. If you could pinch down on the front of the chaffer enough to even out the air flow, I bet you will really get nice results. If you can't do that, you could probably get some additional improvement with the deflector. Since we can now keep a large amount of light material suspended, we now routinely over-thresh the crop, chew up the residue with the rotor, run very light amounts of return, and get very clean samples. We use a return volume monitor to help us set both the chaffer and the sieve.