Combines Not cutting clean

[Fishdog]

I had the same problem with a 820 head I bought last year to put on my R40. It had the crary knife bar setup. I changed out all of the guards and knifes and it was still cutting ragged. I called crary and they said I should be running at between 500 to 600 RPM. I looked for NDDan post on speeds but could not find it. My drive pulley was the small 6.IJIJ" pulley. Found in the parts manual that the 9.IJIJ" pulley for the rigid heads was rated at 565 RPM. I went with the next size smaller--8.4IJIJ" pulley. Cuts great now. I also adjust the cutter bar so the knifes are pointed at a slight angle down. Now cutting very low to the ground. Only problem now are badger holes. Have to stop and pull dirt off the head now and then.

 

[NDDan]

Searched high and low for that post I made on these speeds and no luck. Here goes again. Keep in mind you could need to change belt length if changing size of pulley. Check belt tentioner to be sure it will be able to keep slack out of belt as it wears or stretches a bit. Also the faster you run box the more likely you pick up a vibration. On the flip side if it should cut better you may reduce overall load the system. 71358711 OD 6.89" 423-428RPM. This is slowest speed and is labeled for use with Gleaner quick cut sickle. 71358971-71415133 OD 7.68" 470-475RPM. labeled as medium speed for Gleaner quick cut and slowest speed for flex with normal Gleaner sickle. Also labeled for 8000 with SCH and 8200's. Was once told by Gleaner that this pulley should be fast enough to cut wheat at 7-8MPH. 71328453 OD 8.27" 507-514RPM. labeled as slowest speed for standard Gleaner sickle in a rigid head and the fastest to be used with Gleaner quick cut. 71371580-71415906 OD 9.13" 565RPM labeled for 7000 and 7200 rigid headers. 71317927-71360112-71360877 OD 9.84" 617RPM labeled as fastest speed for rigid headers

 

[Rolf]

We have a 94 vintage 830 flex, PTO along back left hand end of header runs at 624 RPM's (fixed speed header drive) We sped our table auger up from 150 odd RPM's to 180 and slowed our Wobble box down with the smallest pulley available to us at the time from AGCO. 5.1_2" Diameter I think!!! Not sure on that. Again don't run knife to fast, as it will act like a wall to incoming crop! I worked out, for the speed I could process crop at! How many mm forward I would travel, to one stroke of the knife section (75mm or 3") You can soon see doing that, how much material needs to be cut at each stroke! Or if you can slow down knife a bit to help with reliability. Spring loaded hold downs make a substantial diffrence to how the knife works as well. We also grind a squared edge to each side of each finger to help with clean cut! Again this help heaps. (9" grinding wheel 30' front four fingered no choke guards!!! can take awhile! ) Rolf

 

[recreati]

I found a used 8.25 pulley to try and tilted the header mount on the feeder house forward one bolt hole so it is now in the middle hole. I was going to put new knives and guards on but they didnt appear that bad so I left the old ones on. last night I got to try it and those two changes have improved the cut and allow the head to run closer. I am happy with the results.