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Discussion Starter · #1 ·
I have a 1680 with a air foil and I am having trouble plugging the returns. 400 rotor speed and 900 fan speed. shoe sieve mostly closed. I tried opening shoe sieve and worked better and no plugging the returns but a lot of junk in the tank. Any help would be appreciated
 

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I have an Airfoil chaffer in my 8820 T2. It requires a lot of air flow to work properly. I can set it to work on low air flow and have a heavy, chaff rich return, or I can crank up the air and have the return chaff free, with under thrashed pods or heads in it. If you are plugging the return, check to see if it is chaff rich, un-thrashed material, or free grain. If your return is chaff, you need more air. If it is just un-thrashed material, and not plugging, then things are right. If you have un-thrashed material and free grain, your lower sieve is either closed too far or, your air is too high. Now the challenging part. If your hopper has nice clean grain, and the return has free grain, then the lower sieve is too far closed. If your hopper has un-thrashed material, and your return has free grain, then you have to cut your air back and also close your lower sieve. Best bet is to catch a sample from your return elevator and see what all is in there. It will give you the best direction as to what changes need to be made.

What crop are you thrashing?
 

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Closely evaluate your rotor and concave settings for what you are running.

Yes, the air foil is made to run high volume of air, but with the shoe closed down, that limits the air thru flow. So if you can set the threshing a bit easier to reduce the cleaning load, it helps a lot.

If the thresher settings must stay where they are, then consider that it just may be a situation out if the working range of the air foil If you have a cloz slat stock chaffer or other style sitting in the shed, put it in for this crop. All styles of components will have their capacity limits. This is why most people end up changing out the concaves when go from wheat to corn etc.

But one other thing that works for me when I need more thru flow of the shoe and chaffer, is to hang an air dam on the rear of the show. Much the same way as there is a rubber air dam on the rear of the chaffer, I have dammed off the tail of the shoe. To get by, and to see if it will help in your situation, take an old cardboard chemical box and cut it up to make an air dam. Then use gorilla tape to secure tot he tail of the shoe.

I lay the cardboard on a surface like the edge of my welding table and bend the cardboard over at about an inch and a half in from the cardboard lip. Then when I lay the cardboard on top of the shoe pan and anchor it with the gorilla tape to the tail of the shoe, it pulls on the tape a lot less than if I tried to tape it without the break over.

Still, the shoe needs to run open somewhat to make the air foil work.

I had run an air foil in a 1680 with the old paddle fan for quite a while. Had it working pretty well for my crops. Then the fan started showing signs of fatigue, so I installed a cross flow fan kit from cih. Worst investment I ever made. Did'nt know just how bad it was until this year when we bought a second 1680 that still has the paddle fan. Dang I wish I still had the paddle fan in the other machine as well. Especially for the high air volume crops. The air foil works on high air volume, not high air pressure.

IMO.
 

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What are you thrashing? Our 1680 has airfoil chaffer and cross flow fan. We have to be careful no to overload the return. The key is to get everything thrashed properly the first time. That way very little will go through the return. Where the return goes back into the rotor we have a cover plate to help thrash returns too. I run max fan speed on pretty much everything except oats, barley, and canola. There can be a very fine line between having a dirty sample and plugging the return.
 

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Discussion Starter · #6 ·
sorry I should have said I am threshing canola and thanks for the input I would like to hear more. Maybe I went from the shoe sieve too far closed to too far open. I will play with it. I can t get my fan to run over 900
 

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I have a 1680 long seive with airfoil, standard rotor and wide space harvest concaves, I run my rotor speed around 600, cleaning seive the same as wheat and 900 on the fan. always under 3% dockage, usually under 2%, occasionally under 1%.
I do have the front section of the cleaning seive removed as it directs on the harvest website for the airfoil (takes a leap of faith to start cutting up a seive for sure).

Good luck
 

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Discussion Starter · #9 ·
Did anybody else cut out the first five rows of louvers. I am not sure I want to do that. I have the cleaning sieve three quarters open and turned down the fan to 800 because I was throwing some canola out the back. Tried it for an hour and it cleaned up the sample. Didn t plug the return and then it......rained..
 

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Yes, I did buy and instal the actual weld in kit for the shoe. It worked ok, but then had issues in heavy grains especially if going down hill at all. So I sold that shoe and bought a new one. Left it alone and has worked fine till this year when it just plain wore out.

Here's a video of mine that I made a couple years of my 1680 in wheat
. It has the stock shoe and the air foil chaffer with the cross flow fan. You can see how far back on the shoe the grain hits, which is why the shoe cut away can work. But if you go down hill, material that should go into the tilings, though a small amount, will sluff forward into the clean grain elevator. You can also see that I have that air dam at the rear of the shoe as when the machine runs empty, there are kernels dancing around on the shoe pan that normally would blow into the tailings. There's other videos of the machine on my channel.
 

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Discussion Starter · #11 ·
Good video doorknob. I guess I won t cut out the first five rows of louvers because I have a few hills as well.
It seems to be working better with the bottom sieve three quarters open than either full open or fully closed, I am still a little concerned I might be throwing some out the back but
I know it is not more than half a bushel an acre counting the seeds on the ground and that includes the pick up loss
 

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On my 1680 am running 750 rotor, 1100 fan and the bottom sieve same as wheat . i am running the harvest services top air foil and there bottom sieve with the cut out. If i close my bottom sieve to much it docent seem to get the wind it needs. I run the same sieve settings from wheat to canola. Just adjust the wind, rotor and concave. A few years ago my fan wouldn't go over 900 rpm and it turned out that the bearing was going on drive pulley. hope this helps
 

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machinest660 I am running my rotor at 400 in low gear and my fan at 850. I am no expert but one of us has to be wrong here.
Depends on your conditions i would guess, This season that is what i was running to get a clean sample and good capacity. There were some years i was able to run my fan slower but this year i needed the wind to get the pods outa the sample, As for rotor speed i only use low gear in lentils or peas. I also have the harvest air redirecting plate and there bottom sieve with the cut out so maybe that will change a bunch of the settings as well. There is no way i could have got away with 400 rpm on the rotor this season lol. With those settings you ran did you get rid of your return plugging?
 
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