Combines BROKEN SICKlE HEADS ON 800 FlEX CUTTERBAR

R_O_M

Guest
1 _ Not familiar with the SCH cutterbar but is the sickle free to move fore and aft as the wobble box arm moves through an arc as it makes it's full strokeIJ The sickle bar should be free to move fore and aft by about probably close to 10 mms from the knife head end to about 3 feet out along the cutter bar. To allow for the arc of the swing of the wobble box arm, we push the wear plates under the hold down clips right back against the bar over the first 3 feet of the bar to allow the sickle to move for and aft as the arm swings through it's arc. 2 _ Is the wobble box set up so that the arc of the knife head is dead flat and exactly parallel with the cutter bar as the arm moves through the full strokeIJ If the wobble box is not mounted correctly and the arm 's stroke is not parallel to the cutter bar then shims may be needed under the box to get it right Also the vertical adjustment on the wobble box arm should be set so that the sickle sections only very lightly touch if at all touching, the finger's cutting edges. This also prevents undue upload on the sickle bar as buildup, dirt and slight misadjustments affect the sickle's operation. If either of these are not set right then breakage of the knife head is the usual result. If your knife bar has a vertical shake at speed about 3 or 4 feet from the knife head, the knife head is not correctly drilled to be parallel to the knife bar. We have found this problem on both the knife heads we have and I think it is a very old design fault from AGCO who have never picked the problem up. This may require heating the knife head , the part bolted onto the sickle bar, [ not the bearing mounting or thread ] just past the threaded end piece and bending the sickle bar mounting section of the knife head down [ or up ] so that the knife runs flat all the way along particularly for the first 3 feet. I can't remember breaking a 500 series flex head knife in the 13 years we have owned the R62 with an average of around 450 _500 Ha's [ 1150 acres ] of flex work per season in lentils. Although one knife head got very worn so I made a new one from a couple of feet of 1 1_4" x 1 1_4"x 1_4 " angle plus two UNF nuts welded into place, a few minutes with the cut off wheel to get the right shape and some drilling through the sickle bar as a jig for the holding bolts. Cost, a few dollars and not the usual gold plated AGCO version. Time; Maybe an hour! We did break the 3_4 UNF thread on the knife arm _ knife head bearing but replaced this by welding a high grade 3_4 UNF bolt onto the bearing housing in place of the broken thread making sure it was exactly parallel with the knife arm and cutter bar. This has proved to be much more substantial and tolerant of shocks than the original threaded section. Another huge advantage is to put a flywheel onto the wobble box drive pulley. This smooths the drive and the knife action and vibration right out, allows cutting of tougher material due to the inertia of the flywheel and triples the life of the box between overhaul as well as reducing wobble box drive belt replacement to about every three years due to the very smooth running of the belt. We have demonstrated what a careful setting up of the knife and wobble box [ plus flywheel ] on the 500 flex head can do by putting a near brim full bowl of water on the knife bar and running the combine and header at full revs with out losing more than a few drops of water. This demo was to John Keller in our workshop. Check Heddy's Hyper Mods in the Hyper Mods section.
 

NDDan

Guest
I would believe you need the new updated heavier left skid plate and the a-arm stabilizer. You are likely getting some deflection of plate when pulling heavy. When the plate gives way the sickle head has to try keep things straight which will only work for very short time. Of course the worse condition of sickle and guards will amplify the problem.
 

bfd

Guest
had some of the same problems and went with a new sickle. this year i went to the roller guides, what a difference. just buy the roller guide kit and not the whole deal. you could put a small gusset from the end of the threaded part to where the top part of the head curves up to go over the first section, did that also with much success.
 

mark

Guest
Are you saying you don't have to buy a new sickle bar IJ SCH reccomends replacing the sickle bar. I could understand if it is an old worn bar. My bar is pretty new.
 

riceman

Guest
We've just replaced the head. Right after we got our 8000 30 footer we started having heads breaking. From advice here on this site I started rebuilding a few of them and beefing them up with keystock. There's room enough to weld keystock to the front sides on the top and bottom. The first one I rebuilt ran almost 2 years and literally just broke last week. The newest SCH head has a vertical triangle peice welded from the 3_4 or 7_8 threaded part and all the way across the top peice. I think that will help a lot but it still looks like it needs the keystock on the leading edges. The head on the 8200 flex I'm running now is different but I haven't got them side by side to really compare them. I have cut wheat and all the all the fall crops with it and haven't broke anything other than a few gaurds and sickle sections. Knock on wood.. Anyone other than me think that the SCH gaurds and sections aren't as tough as they were a few years agoIJIJ After running the 8000 series head for 4 years I could count the number of broken gaurds on one hand and this year I've broken twice that many already. Same part number also. Just thinking that the steel is weaker. Price isn't though.
 

bfd

Guest
i personally didn't have to buy the gards. i did though buy a sickle and roller guides. if you just dot your sickle, stay with it.
 
 
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