Combines Why do the impellers have that backflipIJ

You are right, the backflip causes more problems than it helps. A few weeks ago, there were some notes on this page in regards to what are called Marlin Ears, which don't have the flips, and they make feeding so easy, you hardly ever hear a grumble. The note was from the inventer himself. If you can't find it let me know, I believe I have the address somewhere.

loewens sells the Martin ears and they have a comparison picture on their web site.

I have looked into the Marlins and talked with Marlin himself.Seems like the reaction I see from users is either they're great,or there was no noticeable improvement.But one thing is sure;that you lose the dust suction in the front.This is not to knock the Marlins.I'm still not sure just what makes them work.Either the backflip is the culprit,or since the Marlins don't hang down as far behind the feeder chain,the crop is allowed to be pitched further into the cone.Maybe it's a combination of both,but I am wondering why a straight impeller wouldn't do the job.That's what I am trying to determine;if a differently modified ear wouldn't accomplish both.