NH 273 Needle Return Question

[steve terplak]

Finished baling for the day a couple days ago and noticed that my knotters didnt look right when blowing chaff off.
Looked in more detail, twine had hung up in the bale hook and twine fingers didnt look right.
Spring which holds the lever in place had broke. Had a spare in the toolbox, went to bale. When it was tying a knot, needles stayed in the up position, drive chain broke and broke a shear pin. Drive chain was old and worn (one side of the roller chain link appeared to be an old break.
Mended the chain, returned the needles, tied a knot and the shear pin broke again. This time the needles did not remain up but they did not return all the way to the home position.
I am wondering if it is an issue with the brake? Or perhaps it needs adjustment.
The needles, when pulling them back to the home position move easily near home but need a little force to pull them back all the way. They remain latched there but can easily be pulled forward.
I compared to our 2nd baler (NH 311). The needles on that do NOT easily move out of home position.

Should the brake be holding the needles firmly in place?
I have a manual (both repair, knotter and operators) but figured i would ask what I should be feeling as far as home tightly the needles are held into the fully retracted position.

I hope my question makes sense.
Thanks in advance.

 

[Tx Jim]

Sounds as if needle brake needs tightening a tad bit.

 

[flying belgian]

Yes, tighten the brake. It is only about the last 3 of needles home position that pull the tthe plunger stop out of chamber so needles need to be in complete home and held there. Sounds like your plunger stop is doing what it needs to. Protecting needles by shearing bolt

 

[DavidP,South Wales]

Hi, Im afraid that I disagree a little with the other replies. If the brake pads are worn down to the rivets tightening will not make any difference. Temove the pads and inspect the amount of lining depth remaining. They have barely 2mm when new. Check that the pads are in full contact with the disc and that are not clogged. When refitting ensure that the springs are not coil-bound.
DavidP,South Wales

 

[SVcummins]

My international 440 was doing that last year tightened up the nuts about 2 turns and fixed it . My big baler does the same thing if I bounce over a rough spot in the field cant remember if I tightened it up yet or not

 

[steve terplak]

I appreciate the quick responses.
My gut was telling me brake and, thinking back, when trying to find our initial problem, I may have grabbed the brake disc with a greasy glove
So, my plan tomorrow, is the hit the disc with some brake kleen., pull the assembly apart and clean crap out of it and off it, ensure the parts are intact and then reassemble and tighten.
In the 45(ish) years this baler has been on the farm I dont believe the brake assembly has ever been monkeyed with. Could be time.

 

[steve terplak]

Just wanted to follow up on this since our problem appears to be solved.
Went out, cleaned everything up, tightened up knotter brake. Noticed that the bolt which mounts that brake-side of the knotter stack to the frame had completely broken off, so it was being held at only one point instead so there was a lot of movement when they needles swung.
Drilled the old stud out and re-bolted.
Checked and adjusted timing of needle clutch according to manual (lined up the marks when the main crank was vertical). - in retrospect when we had repaired the chain yesterday, we had not been careful in lining it up accurately.

Started to bale, first knot tied perfectly and BOOM. Shear pin.
Noticed the needles were not in the home positionfigured the brake was allowing them to drift. Tighten brake, replace shear pin, and back at it.
BOOM. Shear pin. Replaced the shear pin and set out again, this time I watched the needle arms more closely rather than the knotters. I had suspected they were drifting but they were not making it home. They were stopping about an inch short. So went back to the clutch where we had timed according to the manual, thought our way through it and decided to advance the drive sprocket by one link (or retardthis was a 5 minute discussion as to whether we were advancing or retardinghahaha).
We were rolling.

Baled roughly 500 without a missed knot or broken shear pin.
273 is back in running orde.r.