cover plates on a conventional concave

Have any of you ever ran cover plates(some call them block off or threshing plates)on a conventional combine concave?I'm not talking about cylinder filler plates but plates that actually block off part of the concave.I put a J.D. row crop head on my Dominator 76 to cut sorghum with and it is about to drive me crazy.I have ALWAYS been able to set my Fords to thresh and clean as good as you could ask for but the 76 has whipped me.The heads of the sorghum is still tight running around 17.5% but we are cutting it anyway because it is already falling.Both Fords are leaving the ground spotless but the 76 is leaving little dingleberrys with about 3-4 seed behind no matter what.Both the Fords and the 76 are identical inside but the 76 is 10"narrower than the Fords.Both Fords have worn bars and concave but the 76 has like new bars and concave.They are all set basically just alike but I have tried the concave and cly speed on the 76 pretty much every way I can and still have this problem.It acts just like the bars and concave are too aggressive and tearing the pods off before they get threshed.I am at my wits end and am considering blocking off the front third of the concave to prevent them from dropping through.The only way I can get it to even remotely get better is run the cly speed higher but then it is cracking the seed bad.I am beginning to understand what J.D. Seller was talking about when he said they were never a big hit in his area now.I finally parked this one and have been just running the Fords because the 76 is just leaving too much for my taste.This Claas has disappointed me from the word go and it is real close to becoming parts for another Ford.Any thoughts?

Haley, does your 76 have a pair of levers coming out on the left hand side of the machine just rearward of the concave... there should be 2 filler plates attached to the concave and these levers swing them up into place individually... i think claas calls them disawning plates...

I have not ran cover plates on the concave but I have had crops act like what you are seeing. Now this will sound crazy but here goes.

Open the concave a little bit and then speed the cylinder up just a little. Then crowd the heck out of the machine,speed up. I mean FILL the concave/cylinder UP. The faster cylinder speed will make the thrashing action be more aggressive but the wider opening and more crop to rub on itself it will usually thrash out better will no damage. Grain rubbing on grain will complete threshing but not damage the grain.

I have had this happen in soft cobbed corn. If you try to thrash it with the cylinder set tight it would split the cob and leave whole rows of corn. Open it up and you would leave corn on whole cobs. Speed the cylinder up and damage the grain. So open the concave up to where you are getting a whole cob and then fill the cylinder up with a faster ground speed.

I have ran grain sorghum I usually had to really push the machine to keep it full in the cylinder/concave area. Then had to watch out and not plug the clean grain elevator.

J.D.,I have tried what you have suggested and it did make some difference.At that time we were only cutting the heads with the row crop head and the sorghum is only making around 40-50 with smaller heads.The fields are kind of rough and it is hard to hold it on the row and run fast enough to really fill it up.It has been misty dreary off and on here almost a week and when we start back we will be cutting flat on the ground just like cutting beans taking in the whole stalk to try to pick up what has already been knocked over by the wind.I am sure that this will change the way this machine is combining but if it doesnt,I was thinking of adding the concave plates as a last resort.This combine seems to have good throughput even though it is smaller than the Fords but in spite of the internals being identical the Dominator hasn't even come close to doing the job separating or cleaning that the Fords do.It is VERY frustrating to have a combine in great shape just sitting because it wont do the job it was supposed to.When I ran it in corn this year it handled 200bpa corn fine going in but every time I checked behind it there was ALWAYS some corn coming off the walkers that Would not go away no matter what speed we ran.I am certainly not a Dominator 6 series fan at the moment.

oj,It does have the levers but the links and the plates are missing.Looks like someone may have reciently changed the concave and never put the plates back in.I was thinking of bolting some strips under the front of the concave through the inspection doors on each side of the combine.

Same as mine then Haley! Could try bolting some flat iron in between the bars, when i got my concave done this past summer, my concave had one in the first opening. I took it out, but no reason that you couldn't cover the first 3 or 4... the first one is probably the worst to do, but i suspect you could leave that one in and you wouldn't notice a thing. I was always told that throwing over the walkers was a sign of combine running over capacity....

I have run a cover plate on the front 1/3 of a conventional Oliver in hard threshing wheat.

It really improved the first pass threshing, much less partly threshed heads in the return, as the thresh was nearly complete on the first time through.

We always had a problem with more soybean pods in the tank than we liked with our IH rotor combines. Fellows on another farm site told me to use cover plates on the front 3 concave sections, just like I do in spring wheat. I had to open the concave farther and slow the rotor a bit more to avoid cracking beans, but the thresh was much better. Eliminated 80% of the bean pods in the grain.

Throwing grain over the walkers is a sign of under threshing. Usually the cylinder/concave area is the limiting factor in capacity. Once it gets past there the rest of the combine can usually keep up, assuming everything is set correctly. Mike

Haley the Dominator being 10 inches narrower would make a big difference in cylinder,walker and sieve/chaffer function. The JD 6600/6620 was one walker narrower than the JD 7700/7720. That 11 inches made a HUGE difference in the capacity of the machine.

Also I wonder about the cylinder and bars you have in the 76. I have ran aftermarket cylinder bars that where too aggressive until they where well worn. Tempe bars are an example of this. I found them to damage corn too much. I preferred Ausherman or JD bars. So I wonder if you put the same type of bars your Ford's have in them if you would have better luck???

Haley, Do you have the rubber flaps down over the top of the walkers. My 96 has a chain adjustment on the right side of the machine. The rubber flap slows the material and lays down on the walker for more aggressive separation. Sorry, to hear your having problems. You might check the speed of the walkers and make sure they are operating at the correct speed. that's my two cents worth. Masseypride