NH 275 Baler knotter woes

So in a nutshell, it now *looks* like it ties properly 100% of the time, but when you tug on the twine for a knotted bale, the left knot seems like it's not tightened and the twine can slide enough to come undone, so it's like it's knotting 100% of the motion, but not completely tight that 20% of them can open up.

So the #1 twine in the disc - no issues here, the disc always holds the #1 twine, and even on the knots that come undone, the #1 twine is always knotted.

When the needles come up, they look like they're in a good position and they're placing the twine into the slot on the twine disc. Since there's always a #1 twine present on every bale and the #1 is knotted, I don't think needle placement has anything to do with this issue.

The fingers are rotating into place, and both #1 and #2 twine are placed next to each other over the billhook.

The billhook rotates with both twines in the correct place, and it goes through the motion of making the knots - and it seems to me that its somewhere in this motion where things must be going a bit off. There's not really any adjustment here except that one locknut with a spring on it for the arm that the billhook roller bearing rides on. I suspect that the twine may be tearing at the billhook rather than the knife leading to a short tail that can pull out (the twine tail doesn't always look like a straight cut) but I can't seem to find any burrs on the billhook either. So I'm at a bit of a loss now. My grandfather was the guru for this old baler, but alas I can no longer ask him about it, so I'm left with the memories of what he's taught me, but I've reached the limits of my knowledge. I'm at the point where I need to gather wisdom and insight from others, or else it's off to the the parts cannon to start replacing parts until it works. Everything seems to match up with the right knotter which is knotting 100%, so I'm at a loss here.

Other pertinent info: Hay dogs - all 5 present and accounted for, no broken hay dog springs. Baling mostly grass, which always seems to be harder to knot properly anyways. Left side of the knotted bales always seem looser - so often got a little bit of banana bale to them, even if I keep the hay loaded into the chamber, so I think it's an issue with the knots being looser and the bale expanding to tighten the knot rather than not filling the chamber all the way. This would seem to correlate with what I've noticed of the knots tightening up as you pull on the twine before they hit the thrower. I have the tension cranked down pretty far, about 12 turns from fully maxed out on the tension knobs. The bales are still perhaps a tad loose yet, so could maybe tighten them up some more, though I cant specifically state I've found much correlation between the bale tightness and more/less success on the left knotter.

I know many others have toiled and struggled with these older knotters. Does anyone have tips/wisdom/things to try they could share?

Thanks! Chris

1) Many said to sharpen the twin knife - I did so, but it didn't make a difference to the consistency/tightness of the knots. 2) I then went through and double checked all of the adjustments following the manual - no change. Knives were in the right spot, twine fingers adjusted correctly, twine discs, overall timing - all came up good. 3) Replace the Billhook - Since nothing else seemed to work, worth a shot, however the bill hook didn't show any appreciable wear on it and while it's been many years since it was replaced it's likely only had a couple thousand bales ran through it. Unfortunately, despite a new billhook and a new pinion it made no difference either in the knotter performance. 4) Nearly ready to admit defeat, I pulled the hay out of the chamber, pulled some twine back with some bungees to sort of mimic having a bale ready to be knotted and slowly cranked the baler over by hand, tripping the knotter and watching the motion. After several knots, I noticed one where the billhook poked through the #2 twine rather than the hook traveling over the #1 and #2 twines to pull the tails through, and then in close comparison to the right hand knotter I noticed that the left knotters billhook wasn't opening as far as the right knotter and unfortunately there's no adjustment for this so I never really took that close of notice to the size of the hook opening. The problem isn't the billhook or the roller on the billhook, but rather the ramp that the billhook roller rides on that forces the hook open had finally worn to the point where it's been causing problems. This likely also explains why it gave more trouble with the 9000 foot twine than the 7200 foot twine rolls. (It's been 20 years since we quit full time farming, but I remember it worked better with the 7200 and we only used the 9000 in a pinch, so it was likely getting worn out back then - now I only bale a few acres each year so I just stuck with the Always use 7200 ft rolls I grew up using).

At any rate, I figured I'd see what I could do with the knotter frame. New Holland Ag online shows $236 limited stock, and Messick's showed not available, and I figured I didn't have much to lose with the current knotter frame anyways - what's the worst that would happen? I'd end up with a baler that still doesn't knot properly... Now if you're a parts purist, you may wish to stop reading here haha

Having noticed that the problem was actually the ramp profile for the billhook roller, I pulled out the knife arm and bill hook so I had clear access to the ramp with the knotter flipped up. Since it needed more material - that's what I gave it! I pulled out the tig welder so I could make us of the fine arc control, and I built up the profile with ER70S2 filler rod. I was careful to follow the same profile and then hand filed the profile, then built it up again in several iterations until the hook was properly opening, then used some 120 then 400 grit sandpaper to smooth out the surface once I had the billhook opening/closing properly. If you do this, be sure to add a little lead-in profile for the billhook roller to reduce the jerk factor (instantaneous acceleration) in the motion. As worn, it looks like it's practically running into a square corner at the right side otherwise. And since this was now a test profile, I put the old billhook back in.

I haven't taken the baler out into the field yet, however I did have a bunch of hay to bale up from open bales I forked off the wagon from 1st cutting and it hasn't missed a single knot now. Before, every time I pulled on the left knotter twine, I could feel it tighten up and about 10-20% would actually pull open either by me pulling on the string or when the kicker tried to throw it. Now, the knots all look properly formed and they're nice and tight so there's no give/tightening up when pulling on the twine. As a result, it's also fixed the slight banana shape the bales took on from the twine tightening up and allowing the left side of the bale to expand. Pictures for clarification of the repair. I do however have one question regarding the knotter frames. The right knotter frame the ramp profile is a part of the frame whereas the left knotter the profile appears to be replaceable (and there's some slight variance in the grease zerk locations). The parts diagram doesn't appear to show this replaceable ramp part however, so I am wondering if the left knotter frame with the replaceable profile is perhaps from a newer series baler? Are the frames interchangeable between this 275 and other models?

Thanks again to everyone for all the suggestions/help!

Chris

Rod