9500 cleaning fan

Does anyone know how to tell the difference between the regular speed fan and the slow speed fan? Grain is not as clean as I think it should be and as hard as it will run is a little over 900 rpms. Wasn't sure if it was just the pulley size or what

I believe the difference is in the drive pulley. With the slower speed fan you still should be able to get into the 1300 range or more (still too slow for corn and beans). Check the stop nuts (double) on the threaded shaft that the fan adjusting motor runs to be sure they haven't walked in on you. If your belt is worn you won't get full speed, either. Mike

I had one once where the fan assembly hardware was not tight enough allowing the shaft to spin inside the blades.

Like has been said if the belt is worn or stretched it doesn't work right. Also, make sure the outer bearing for the split adjust sheaves isn't out. I couldn't get fan speed up this year all of the sudden and the outer bearing was out. The belt should run to the top edge of the pulley when in high speed. I think your belt may be to blame.

I think that the belt should be running at the bottom of the driven pulley for high speed and the top for slow. You should be able to get enough air to blow a few beans over it it is working properly.

Tom, you probably already know this but for those that don't there is a common misconception about how a cleaning shoe works. Some folks will see crop on the ground and instantly assume it was "blown over". They turn down the air and wonder why they get MORE crop on the ground. For beans, it's actually pretty hard to blow beans out the back of a combine if the cleaning shoe is set properly. There should be a high VOLUME of air but not high PRESSURE of air. The chaff should never touch the chaffer (top screen). If it does, there is not enough air. Many times chaff is bouncing on the chaffer and carries grain with it. Turning down the air only compounds this problem. Also, many think the chaffer should be set pretty tight to eliminate trash. While this can be done in crops that don't take a lot of air, in corn and soybeans it is not the approach to take. If the chaffer openings are too small the effect is the same as your finger on a garden hose. Grain will hit this pressure area and get slung out of the back of the combine. If the chaffer is opened more and the air is turned UP you get more air to clean but that additional air is less likely to carry grain out the back, but it WILL carry more chaff and trash. It's pretty hard to blow grain out of a combine if the shoe is set correctly, even if the fan is turning pretty fast. Mike

Mike,

I agree with you. I was just trying to make the point that a variable speed pully the driven pully should have the belt running in the bottom of the pully for the fastest speed and the top of the pully for the slowest.