Cleaning fan speed on 4420

agman · Jun 21, 2011

New on a 4420 and the manual tells me the cleaning fan speed recommendations for different crops. I understand how to adjust it, but have no idea how you are supposed to know what speed it is turning at. There is no fixed tach for it. Is this just a play with it until you like it kind of deal? Thanks.

Case Nutty 1660 · Jun 21, 2011

I use a photo/tach for my Case machines but they are a little pricy cnt

JMS/.MN · Jun 21, 2011

If you know both top speed and low speed, and adjust with a crank, just count total turns from one end to the other. # turns divided into speed change equals rpm change per turn. That"s how I figure on my F2, since the mice visited.

Mike Aylward · Jun 21, 2011

Agman, just so you know, people ran combines for years with no way of knowing for sure how fast the fan was running. You want enough air to float the chaff off the shoe without admitting too much material into the tailings return auger. The speed will vary with each crop and condition. The chaff should never just dribble off the top shoe but actually be blown or floated off. The chaff and the grain should never be together or you will have problems. Most people run too little air instead of too much. A person needs to know why you set the fan speed at a certain point. The actual rpm's you get is only a reference point. Mike

55 50 Ron · Jun 21, 2011

Does the fan shaft have a dimple in the end where you can hold a tachometer up to? That will give you a pretty accurate RPM reading.

Anonymous-0 · Jun 22, 2011

Is your 4420 hydro? Cousin had a 6620 later model and I am remembering you could look at fan speed with the selector switch for ground speed read out. I know this is the arrangement on a 9400. Like lower post says we used fan speed for ref only, run her up until grain in tank is clean and then watch the ground where crop is still standing next to where combine passed on last round. If there is a sprinkle of grain on the ground turn the fan back about 50 RPM at a time.

paul Em · Jun 23, 2011

You can get a handheld digital tach for about $70
and check the rpm of any pulley you want. You just
attach a reflective sticker on the pulley and shoot
the handheld at it.

Cleaning fan speed on 4420

agman

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Case Nutty 1660

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JMS/.MN

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Mike Aylward

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55 50 Ron

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Anonymous-0

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paul Em

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