Combines the difference between early 1680 and late 1680

We have a long shoe 1680 that we use in wheat and milo. I feel the limiting factor on the machine is overloading the tailings elevator. We try to get a really clean sample, too clean some would argue, but we store the grain on the farm and dont want to deal with the bugs you can get in trashy wheat. Really the only way to keep the sample super-clean is to pinch down on the lower sieve which causes the excess return and then the slip clutch on the return chatters every once in a while. Ive been told that the root cause of the problem is the lack of air flow through the rear of the shoe sieve and the rear of the chaffer. We had the paddle fan, but switched it over to the cross flow several years ago. The cross flow may have helped a little, but not much, and it may not put out quite as much air as the old paddle fan. Some recommend pinching down the front of the chaffer to help force more air to the rear, but weve been running a fixed air foil chaffer which doesnt have that capability. I think the problem may actually be aggravated by extending the shoe rearward. Scroll down to the posts on December 4th to read about a product designed to deflect the air evenly to the rear of the sieves which allows the MOG to stay suspended. We have one of these on back order right now. The manufacturer claims that it will actually work best in the short shoe model, making it out perform the long shoe. Ill know more by mid June when the wheat harvest gets started. I think I would value the Cummins engine in the later 1680s more than the size of the shoe. I would also look for a specialty rotor, but realize that you will need to make the threshing more aggressive in the wheat (use Gordon Cover Plates) and reduce the separation (use slotted grates) compared to how you set the machine up for corn (no cover plates and keystock grates).

I have been running a 91 1680 for a lot of hours in milo and wheat and while I have never run a short 1680 I have heard it makes a big difference. When I was looking for my machine I talked to several case_ih people and they all told me "it made a new machine out of the 1680". I do not have the cross flow fan but have had limited trouble cleaning crops. I would not run a fixed chaffer simple because I adjust mine all the time. One thing I find very interesting when looking at the newer machines is that they are the same as a long cleaning system 1680 except for the horses. hope this helps