Well, I only cut small grains, but here's my take (I have a pair of 1680's, almost twins but 1 has a specialty and 1 has a standard)-
The Specialty Rotor is definitely more aggressive. Tough conditions, it thrashes better, and we normally run it 2-300 RPM slower to get the same results. Tears the straw up more. But, we have had more trouble getting whitecaps out in the past, so I run a full set of Gordon bars in it to make it perform more like a standard.
An AFX has the same bars as the specialty. While I don't run one, I have Kile fronts on the other two combines, a pair of 2188's with standard rotors. WAY less rumble in tough crops, feed nicer, and appears to be cleaner samples than with elephant ears. So personally, while I think the front of an AFX is probably a good deal, I'd end up putting Gordon bars on it in my conditions, to make it more like a standard.
So if I understand you you are trying to make them preform like a standard rotor except be able to run in tougher conditions. What are the Gordon bars and the kile fronts? You are trying to explain this to someone who is a green man currently but she is showing her age and lack of capacity for the current genetics and unfortunately this year the higher moistures.
The standard rotor has longer rasp bars along the front half, and the back half has four straight separator bars that run over the grates. A specialty rotor has a bunch of smaller rasp bars staggered across the entire length of the rotor. An AFX rotor is essentially a specialty with a spiral nose replacing the two large impeller blades ("elephant ears").
We have always had standard rotors, and they work well in all crops we grow. However, they do not like tough conditions, like green stem beans or big Russian thistles. That's where the specialty comes in. Like jakeh said, it will work better in tougher crops, with less rumbling. We've tried a specialty rotor in wheat once and didn't like it, and the guys at our dealer will say a standard is the way to go for wheat. Last winter we thought about putting an aftermarket AFX nose on our rotor, but our dealer said we wouldn't see a lot of benefit, so we just retained the factory elephant ears.
Here's a standard rotor for reference:
On a side note, I'm kind of surprised this thread hasn't got more replies. Maybe someone will chime in to tell me where I'm wrong.
The specialty rotor is much much more aggressive than the standard and the only difference in the specialty rotor and the afx is the spiral on the front. The afx rotor is really nice in heavier greener crops where alot of "rumble" is experienced, the afx rotor we had in a 2188 nearly eliminated the rumble till crops were wet then a small amount of rumble starts. The advantage the afx brings is by feeding the crop more evenly into the concaves. We've never dealt much with the standard rotors.
okpanhandle I agree with you the standard is a great wheat roter for the most part however I think your dealer is on drugs I put a kile on the front of my old combine & I swore someone stole the old combine and gave me a much better combine . I will not run another one without it ever.
Montana, I agree with you, I put an aftermarket AFX nose on my 1680 with a standard rotor. I could not believe the difference it made. Especially when we get to the tame rye we cut. I always find rye is so tough and before it would just go in in wads now it feeds so much better. Like you said I thought I had gotten a new combine.
We run a specialty rotor with a Loewen front end kit for corn, dry beans and wheat. I went from 3.5 to 4.5 mph in wheat. 2.5 to 3.5 in beans. 3.5 to 4.5 in corn just from adding the front end spiral. The actually CaseIH AFX has different placings of the rasps and one additional row of rasps at the front. I wish we had had the money at the time to get the factory one.
Basically, hesston, you'll want a specialty or AFX. I think you'll be happier in beans with the more aggressive rotors. Our standard rotor worked fine in beans, but our beans were short and dry; not much of a challenge.
I figured everyone would say I was wrong about aftermarket AFX kits, but that's why this is usually a good place to get information. What year was the AFX released? We rented a '03 2388 a few years ago and I thought it had the AFX rotor. I couldn't go near as fast as I expected, but it was a completely new (to me) combine, we were in better wheat than usual, and the 1010 header sucked. The floor was so rusted up it wouldn't feed evenly and it took most of harvest to slick up, even after we coated the thing with diesel.
The afx is definitely the way to go for green stem beans, we had one put in a 2188 in 05 or 06 and it was much more aggressive than the regular specialty, we never really cut much corn with it but it was really nice and would definitely say if you were able to get one to get one. I think the afx came out in 04, I'm pretty sure they started puttin them in the 2388's the year case moved the air screen back to the side of the combine.
Thanks for the info guy's.
Now the tough question how many of you guys wish you could be level on a side hill like the JD sidehill machines or the hillco levelers. Because we have a '80 model 6620 sidehill that I'm pretty sure my brother intends on being buried in because of the sidehill option and the fact that he has done an excellent job maintaining the old girl, but 5860 hrs and 230 bu. corn that is 27% puts her at about mach 1.9 speed. I was joking with him the other day if he had time to take population counts from the cab!
I know I'm late on this but from my experience the difference between the standard rotor and the specility rotor is the placement if the rotor bars. The standard rotor bar has more bar to concave contact and there for is a better thrashing rotor. The problem with the standard rotor was that it was not aggressive enough in hard to feed crops such as green stem beans. The specility rotor has more space between the bars that makes it more agressive but not better thrashing. The difference between the AFX rotor and the Specility rotor is the auger on the front. If you look at the AFX auger you will see that in one revelution it moves twice as much crop. More agressive-right? Now- The AFX rotor and the specility rotor have taken care of being more agressive but they are still not as good of a thrashing rotor as the standard. Wouldn't it be nice to have a rotor that is super agressive to use less power and would feed the crop evenly and still give you an excellent thrash?? Here is my advice. #1 Put a Kile front on your standard rotor. #2 Take out all of the stright bars on the front of the standard rotor.( They are retarder bars and do nothing but hold the crop over the concave longer that has been proven not need. We have taken the stright bars out of standard rotors for over 20 years) #3 Find somebody like me to remove every other tooth from your standard rotor bars. ( $527 or $641 job) Removing every other makes the bar more agressive. #4 Replace the back stright bars with the Estes hardfaced Scallop bar and add a set of "The Disrupter lugs. End result- Agressive feeding, Better Thrashing, no rotor rumble in beans, and no rotor loss in corn. You must set the vains in the middle position for both beans or corn. (you don't need to speed the vains up in beans because the disrupter lugs and scallop bars are cutting up your straw and you don't have to slow the vains down in corn because the disrupter lugs and scallop bars are cutting up the shucks that was the reason for your rotor loss. The system does work and if you have a specility rotor you just need to remove the retarder or seperating bars on the back half of the rotor and spike it up with rice spike bars. My web site (cmweldinginc.com) I am a consultant for C M Welding Inc in Frankfort In. and my phone is 765-891-1722 Call me with any and all questions any time. Thank you for your time. Donnie