Auger Design

I am trying to decide if the auger to the wagon on my New Idea 329 Sheller is worn out. I have had some issues of drive line breakage to the auger and later finding the auger full of wet corn (say 20 %). This is the basis of my question.

My question is: is there a table or design guideline of some form of how tight an auger should be in the tube it is running for a given angle and grain being conveyed? On my Sheller the auger flights have about 7/16" to 1/2" clearance to the tube wall. That is with the auger biased all the way to one side of the auger tube. I have no way of knowing if this clearance is excessive or not. Are there any other factors I am missing?

Other factors that I am aware of is: 1. the tube has a bow in it from end to end, about 2 - 3", and 2. the tube has a somewhat flattened area from wagon hits when going through ditches. The dents were repaired to some extent but there still is an obvious flat area about 3 - 4" wide and 2 - 3 ft long. The tube is about 6" in diameter.

I am looking for some engineering data that guides the design of augers.

Thanks.

Paul, La Crosse, WI

I think the screw inside a 6" tube only measures 5". So it sounds like your auger is not worn. But I would think that bow in the tube would be really hard on it.

That info is available; I read it back in the late 70's when I was researching coning when material is deposited until it builds an inverted cone. The coning causes particles to separate by weight & density so fertilizer that is scooped from the bottom is not the same mixture as went into the cone at the top. (Never did find a solution to that problem.)

Yes Bob's right 1/2" clearance in the tube, and when they get worn down they pull harder causing drive line failures..

I rebuilt the hopper and incline on a 60 some foot grain auger this last fall. The main long auger was an 8 inch auger. The incline and the hopper was more like a 7". According a replacement auger supplier as the auger gets larger in diameter the clearances get larger. I believe on the 8 inch tube it was around 1/2 to 3/4 each side. I was surprised. Certainly those dents do not help as well as the bow. Too much drag. Wet corn and the incline all increase the power needed. 20% moisture isn't that high. Also remember you might be raising more bushels per acre compared to when that picker was new. A 6" auger should carry quite a bit of corn. You could replace the tubing. I buy 10 and 20 foot chunks of 6" tubing with 1/8" walls from an area metal supplier. They stock it. I can't remember if it is around $4.00 a foot. Might be that the auger is OK. The last auger flighting I bought was from Nebraska I think - shipped UPS. Goggle auger flighting and you will find them. They send it via UPS in 5 foot pieces interwoven into each other. Cut the old off and install the new or maybe just the one end needs to be repaired. Again I think I paid about $4.00 a foot. I have even cut the dented section out of a auger tube and reattached with a collar. I would check to see that the drive components are not slipping. If slipping is going on the auger will fill up and the power requirement will increase to the point that it can't turn it. Good luck.

The bow and the dents are your problem. As well as the increase in yield today over 30 years ago when it was made.

Great input everyone. Thanks a bunch. This gives me confidence I am heading in the right direction. I will be getting a new tube and use the existing auger. I just need to figure out what my tube acquisition direction is. I have a lead on a new tube in Dodgeville WI but don't have confirmation and cost yet. I think the Holidays slowed the response, I will be following up with them. If that does not pan out I will load up everything and head for Winona MN. There is a company there that mfg's and repairs augers.

Thanks again. I appreciate it.

Paul