Why Does My Baler Keep Missing Knots

Missed knots turn a good hay day into a pile of loose bales. Knotter trouble usually comes from twine, dirt, tension or worn tying parts, and a methodical check can sort it out.

Key points

Check twine type, storage and feeding first.
Clean the knotters and tensioners thoroughly.
Worn billhooks and bent needles cause repeat misses.
Always lock out the baler before working on it.

How does a baler tie a knot?

On a square baler, needles carry twine up and around the bale while the knotter ties the ends together and cuts the twine. Several parts must work in the right order and in time: twine disc, billhook, knife and twine holder. If any part is dirty, worn or out of time, a knot misses.

Before adjusting anything, work out the pattern. Does every bale miss, or only some? Does one knotter miss more than the others? Those clues are valuable.

Keep a log of which knotter missed on each bale during a test run. Marking bales with the knotter number helps you find the culprit quickly.

Could the twine be the problem?

Twine quality and type matter. Twine that is too thin, too weak, damp, uneven or the wrong kind for your baler will fail to knot or will break. Check the twine specification in your baler manual and buy to it.

Store twine dry and keep the cans clean. Twine that has been chewed by mice or sat in a wet shed often causes trouble. Check that twine feeds freely from the can through the guides and tension plates.

Use the type and strength the baler manual specifies.
Check the twine path for sharp edges or burrs.
Make sure the twine is not tangled in the can.
Keep twine in a dry place.

How does twine tension affect knots?

Too much or too little tension at the twine tensioner prevents the knot from forming. Tension that varies between knotters causes one to miss. Setting it right is a matter of following your manual and adjusting a little at a time.

A tensioner packed with dust or chaff does not hold twine consistently. Clean it and check that springs and plates move freely.

Check that the twine is threaded through the guides in the order shown in your manual. A missed eye or an extra wrap changes tension without any visible fault.

What should you inspect on the knotter?

Dust, chaff and dried hay juice build up around the knotter and slow its parts. Clean each knotter thoroughly, following the manual. Look at the billhook for wear, the knife for sharpness and the twine disc for rough spots or cracks.

Knotter parts wear with use. A worn billhook or loose parts may not grip twine. These are replaced as sets in many cases and are best installed and timed according to the service manual.

After cleaning, run the baler empty with the PTO at the correct speed from a safe position and watch the knotter cycle, with all shields in place.

Do needles, bale length and density matter?

Bent or misaligned needles place the twine in the wrong spot. Check that the needles enter the knotter area cleanly. A bale that is too dense or very uneven can put strain on the twine and cause breaks and misses.

Ground conditions and windrow shape change density too. In a 30-acre field of heavy, uneven windrows, density swings can throw knots off. Keep a consistent feed and adjust the tension on the bale chamber as the manual describes.

Moisture matters too. Damp hay makes denser, heavier bales, and wet twine is weaker, so check that hay is dry enough as extension guidance recommends.

How do you work on a baler safely?

Shut off the tractor, disengage the PTO, remove the key and wait for all movement to stop before touching a knotter or needle. Balers store energy in springs and flywheels, and needles can swing without warning. Use the lockout steps in your baler manual.

Never clear a jam or work on a knotter with the baler running. Keep shields in place, and keep children and bystanders away from the machine.

Shut off and remove the key.
Wait for flywheel and parts to stop.
Follow the manual's steps for blocking needles.
Wear gloves and eye protection.

When is it not worth DIY?

Cleaning, twine checks and tension adjustment are common owner tasks. Retiming the knotter, replacing billhooks and rebuilding needle drives are jobs for an experienced baler mechanic or the dealer service department, using the parts the manufacturer specifies.

When to get help: Call an experienced baler mechanic or the dealer service department for knotter timing, needle drive repairs or worn parts. Always shut down, remove the key and wait for all movement to stop before working on a baler.

Sources and further reading

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