Combines air deflector

[GRS]

The front of the chaffer is starved for air because the bottom sieve is so far foward. 3_4 of the air will pass through the bottom sieve to get to the top sieve. The more you close the bottom sieve, the more you force the air back, cutting off the air to the front of the chaffer. This really cuts the capacity of the top sieve. One of my observations has been that it would be very difficult to blow grain from the front, all the way to the back and still have chaff in the return. The chaff needs to be lifted as it is coming off the fingers. It takes vary little air to keep the trash floating once it is lifted. The bottom sieve dosen't need much air because light trash should not have been able to fall past the top sieve. By opening up the front section of the lower sieve, you spread the air out more even on the chaffer. The chaffer needs air volume, not volicity. Trying to force air through a close adjusted bottom sieve takes volicity to get the volume thats needed. Case IH had a 1660 that had sections cut away on the sides, so you could see what makes it tick. They would display this machine at their combine clinics. This was one of the areas that was cut away. When you can see this from the side angle, it looks very differant than, from the back angle. Putting the bottom sieve that far foward and blocking the fan was a bad idea for IH. Ray Stoukel (I don't think I spelled his name right) told us this 25 years ago. Harvesting Pearle Millet, (The plant is very leafy and looks similer to milo, the heads look similar to cat tails) the moog is very heavy, thick, and damp and slightly green. Before this modifecation you could crank the fan up and blow millet all over the ground, run a full return, and still not get it to unload out of the combine or trucks. You could only drive as fast as the return would let you go, about one mph. Now its hp limit of about 2.5 mph. I don't know how this would work with the deflector if it puts more air under the bottom sieve. Are they adjustable in any wayIJ Thanks for the information.

 

[Farm_Kid2]

I think we'll have to disagree on this point. I'm convinced that the front of the chaffer sees the highest air velocity and volume on a factory machine. The rear of the chaffer gets very little air flow in comparison, allowing the MOG to fall down through and go straight into the return auger. The deflector does a great job of evening out the air flow on the chaffer, and I think it does a good job of keeping the sieve air even, but that is difficult to inspect visually. If you have access to a factory machine, tie some ribbons on the chaffer about every foot from the front to the back. Watch them as the fan speed is varied, and you'll see the front ribbons stand up immediately and the rear ribbons struggle to lift until the fan is running at very high speed. Here is a link for more info on the deflector. Thanks for explaining your sieve mod to me. I wonder how it would work with the deflector to keep corn out of the fanIJ Mike

 

[GRS]

I don't see how you can make any comparision to a few ribbions, to a completely loaded sieve. I would be interested in seeing what position the ribbions would be in when you have all that materal holding down the air blast. If the light chaff can fall back down to the back, and make it through the chaffer, why can't the grain. Rotate your machine untill you bottom sieve is all the way foward. Take a tape measure, and from the back locate the front of the bottom sieve. locate that point on the outside of the machine and mark it. Now locate the front of the chaffer were the first kernal of grain can fall straight down, and put that location on the outside of the machine. I think you will find this intresting. With your set up, it looks like to me a lower sieve adj. greatly affects your air blast volume and direction. A tight lower sieve setting would require high fan speed with lots of velocity. Just my thoughts.

 

[Potsdam_Boy]

I've seen where they remove the front 5-6 fins on bottom sieve. Whats your thoughts on thatIJ

 

[GRS]

On our 1480 I had removed 8, but when we got our 2188 I just opened the louvers. I think leaving the louvers gives it more air direction control. This way if you don't like it you can put it back like it came. If I can find a broken chaffer with the adjustable front section, I will try to use the front section adjuster on the front of the bottom sieve, to make it adjustable. I think this would let you fine tune the air direction.

 

[larry]

I have about 5 or 6 rows of fins off of the front of the botteom sieve on my old 1480. I have a fan throat kit from "harvest services". It directs the air in on the sides a bit of the fan throat and under the chaffer more. Plus I have a fixed air foil chaffer. Don't know if this system is the "best" set up for small grains but its' a hell of a lot better then the factory set up. With the factory set up I found in Canola it did a poor job. When you cranked the wind up it would blow the canola out on the sides. I spent a couple days one time trying all kinds of setting and mods. What I ended up with that year worked great, you couldn't throw canola out if you tried. I've been using the same set up ever since. I found though that not every year is the same of course. Some times I think that having an adjustable air foil chaffer might be good idea some years. When the canola is super dry and really overloads the chaffer.

 

[GRS]

What is Canola, and what is it used forIJ I have always heard of it, but never seen it. Millet is a real small seed. It is mostly use for pasture.