What combines are we talking about?????????60, 70 series, if so I really doubt your kernel damage is coming from the feed accelerator. On all 60 and 70 series there was a major change to the feederhouse conveyor drive chain sprocket, the small sprocket is as large as the large one was on 50series.This is something we run into right away on 60series intro. in 2004.Our solution order and install a 50 series sprocket , drop the front edge of the upper chain guide, shorten chain and go.The chain never needs too run that fast for corn, don't care if it's a 4rw 0r a 18rw. it will feed fine.Just remember to switch back sprocket when doing grains or soybeans.Also mack sure your feederhouse drum is up [handles 60-70].Last but not least, with feederhouse lowered adjust conveyor chain so it clears top chain guides by 1.5 " in the center of top access doors. This will get chain tight enough you lessen the chance of grinding corn, and will make your feederhouse floor last longer, or jumping a chain out of time.If we are talking 50series, you can adjust the chain the same way and you should havethe proper size sprocket already installed.There is alot of confusion about conveyor drum height on the old style drum adjusters, the top cam should point to the 12 o clock position for all crops, the main ajustment is done on the lower bolt, when the eccentric[one inch offset]is visable above lower bolt that is properly set for corn , when below it is set for grain and soybeans , make sure you adjust left and right sides the same.Once you have top cam pointed to up , or 12 oclock you need not ever adjust that again regardless of crop, this will isure proper feeding but will keep chain off of floor.We have had excellent results with sts combines in high yielding corn, and yes we do use the slow down kits for accelerator, but only for edible beans, questions just ask??Deerefever.
If you remove all the feed accelerator plates you WILL see a huge difference in your sample,I dont see why the feeder chain would cause damage to the kernels no matter how fast its running. We have tried alot of things to clean up corn samples and removing the feed accelerator plates was the #1 improvement for kernel damage.