6600 Grinding Corn

I have a 6600 Hydro with a 329 motor, old style 444 head that the stalk rolls are getting wore, so a lot of stalks go thru the combine. I started corn with the concave set on 17 and cylinder set at 600 rpm. It seemed to be doing a good job, getting the corn off of the cob and a really clean sample. Quite a bit of corn going thru the return. When I unloaded the first wagon, there was a lots of cracked corn in it. The cobs are broken cross ways, not length wise. Some of the cobs have 1/3 to 1/2 of the kernel still on the cob. I slowed the cylinder down to 500 and then there was lots of corn left on the cob. I speeded up to 550 and still corn on cob. Set it back to 600 and closed cylinder, I'm down to 14 and still getting corn on the cob and cracked corn. Cobs are broken, not split. Corn is testing 12 to 15%, yields vary from about 20 on the sandy spots to 180+ on the good ground. Running in 3rd gear about 3 on the hydro. Where do I go next? I thought you opened the concaves and started closing then until all the corn came off of the ear. The cracked corn tells me the cylinder is too fast, but when I slow it down it doesn't get all the corn off of the cob. Suggestions?? Thanks, Chris

You need to tighten the concave down more until your splitting the cobs long ways. Your too far open and the cobs are going through long ways not cross ways. Get it tighter and then you can slow your cylinder speed down. I know it sound strange to have broken cobs and still needing to go tighter but that is what should work in your situation. Also your going to have some trouble anyway with the widely varying crop yield. The cob/ears are way different in size and that makes setting the combine hard.

Also disregard the setting numbers other than to tell you where YOUR setting your machine. Meaning that unless you zero the cylinder and then set the gauge then the numbers will not mean anything much when comparing them to the book or other combines. I never even pay any attention to what the numbers are. I open the rock trap and set the concave to just a little bigger than the cobs in the current crop. Then go up or down after looking at the cobs coming out of the combine.

Something is out of whack in your cylinder. Being several things. Start by zeroing out your cylinder. Are the rasp bars good? Concaves?

Thanks, I'll start over setting it after work today. I can't predict yield by watching it go thru the combine, but there are small ears on the sandy areas instead of nubbins that go right thru the stripper plates, so it should be a good crop.

I got along much better today. I closed the cylinder 3 cranks and started out and checked on the straw walkers. Broken up cobs with corn on them. Opened it up until I had mostly all unsplit cobs. Slowed cylinder down to 400, kernels still on cob. Speeded it up to 450 and cobs are shelled with only 1 or 2 kernels still attached once in a while. Still grinding a small amount, but it's at an acceptable level to me. Closed the chaffer and sieve a little, fairly clean in the tank, a few pieces of stalk and cob ends. When I'm on flat ground, there is nothing in the return, but on hillsides or going uphill, there is some corn coming thru the return, but nothing coming out the back. I worked until noon, came home and ate. Pulled 2 wagons in from the field and unloaded and then combined 5 wagons and a hopper full and unloaded into the bin and took wagons back out. Quit at 7, I'm pooped!!! It was so windy today that when I was unloading the hopper into the wagons, the wind was blowing corn over the end of the wagons. Chris