Oliver 520 baler knotter twine disc (6 slots)

I have the parts book and the operator's manuals. My parts manual only shows the 6 slot disc. However, my operators manual does cover adjustment of either.

Looking at the pictures in my manual, the 4 slot disc uses a drive gear with 8 teeth, the 6 slot has 6 teeth. The worm gear looks like it has 3 wraps for the 4 slot and 2 wraps for the 6 slot, but that could be a deceiving picture.

I can't tell if there is any difference in the knife arms or the drive gears.

I would suggest replacing with what you have already since it would be the least expensive route, but I have my doubts that you can get the 6 slot discs. (I tried to get new a twine finger - not available). You'll just have to inquire.

Maybe you can help me. This is my first go around with the 520. I have a couple of NH's so I'm no stranger to the "deering" knotter.

I'm having tying problems with my baler. I've replaced both billhooks with new and replaced the knife blades just because I had the knife/stripper arms off. My baler is still doing the same thing even after replacement of parts and setting the knotters per the manual with the exception of twine tension for the twine disc. The problem is the knots seem to hang up in the billhooks. I've tried taking the tension off the hook, tightening the hook, tightening the tension on the string as it comes from the twine box, and adjusting bale tension up and down.

Now, the knife arms on my baler are painted gray, so I know they aren't original. They have the shape as shown in my manual but I did note that there is free play from side to side, until the ball at the end strikes the drive casting. Is this normal? They rub the billhooks like they should. I've watched it tie and Ive seen it break the string when it doesn't drop out of the knotter.

Thus, I"m working toward replacing the twine disc and holder but no one seems to be able to find a 6 slot twine disc so will try to replace enough parts to switch to a 4 slot twine disc. Your Op manual and parts catalog for the 520 are different from mine. My Op (Dec 65 441-023) says nothing about a 4 slot twine disc (what does your manual indicate is different in adjusting the 4 vs the 6 ? ). But my Parts (Feb 68 442-579) lists parts for both the 4 & 6 slot disc.

The knotter most similar to the Oliver 520 (based upon looking at parts diagrams) is the New Holland 65 and Hesston 4500 with the Hesston being a better match. Since you have NH balers (the 68 seems to be older than the 65), how do you rate the NH for potential replacement parts for the Oliver 520 ?

As for my knife/stripper arms, there is no grooves on mine, just free play. It's every other bale that the twine ends (not the knot) remain tight in the billhook. The knife arm/stripper will push the knot off, but there is just enough twine left in the billhook to hang. I can use a pair of needle nose or a screw driver and flip the billhook open. Most of the time it will pull free on its own. Other times it will break the string. The arms that put tension on the billhook rollers don't look worn and I even swapped them side to side with no change. I haven't played around with the drive gears or tried bending the knife stripper arm. When I pick the knotter up and check the stripper arm it's right on. There isn't much length left on the ends of the twine after the knot is made (maybe 1/2") so I'm surprised it's getting stuck fast.

Hesston bought the Oliver 710/720 baler design when Oliver stopped making balers. (The 520 became the 710 more or less) The Hesston 4500 would probably be the best fit for parts. However, from comparing my two balers I think most everything from the NH68 except for the knife arms would work. I may try putting one of my knife arms on and manual operating the knotters just to see what happens. Worst I could do is break the knife arm... I couldn't be anymore perplexed with the 520.

You seemed to have tried / checked the right things for your 520 tying problem. Does the twine hang up on both knotters or just on one? When it ties OK do the knots look normal? Apparently the bill hook tongue is closing on the ends of the cut twine and keeping the twine from pulling off the billhook. Hard to believe that the next bale won't pull the cut ends off the hook without breaking the string (unless the knife not making a complete cut). Maybe decreasing the tension on the tongue would help (you tried that). Possibly changing the timing of the twine disc would help prevent the tongue from closing upon the twine ends. Your timing procedure (align left side of slot with cleaner edge) would appear to retard the disc more than indicated in my manual (leave about one-eight inch between left edge of notch and nearest point of the twine holder) thus would not have the full slot open to receive the twine from the needle. Generally I've not been able to keep the timing set as small as the one-eight inch and seems to tie ok. Maybe changing the twine disc timing would present the twine differently to the billhook and the twine end would not catch. Where does the twine lay on your billhooks? My needles rub the side of the knotter housing and places the twine about three-fourth of the way from the end of the bill hook. Or maybe the stripper arms position the twine too far to the left on the billhook tongue. Maybe positioning too far to the left would place the twine ends underneath the pointed spike of the tongue? If one knotter works try switching stripper arms or I would think your NH balers arms should be exactly the same (your arms seem to be tight enough against the billhook and travel past it far enough).

For what ever its worth these are my rambling thoughts. Good Luck.