The wire-tie baler, twine-tie baler, drive train protection, timing, planning and preparation.

by GJ Stoltz (Reg Eng Tech)

Last month we started off with baler preparation. The two types of strands available for tying bales are wire and twine.

Wire-tie baler

Fill the wire box with the correct size of wire. When the front coils run out of wire, place the rear coils forward and add two new cartons of wire in the wire box. Make sure all wire pulleys turn freely.

Thread the wire through the pulleys, guides and needles as indicated by the operator’s manual of that particular machine. The needles must be in the “home” position when fitting the wire.

When both strands of wire are in po­sition, trip the bale measurement arm and turn the flywheel counter clock­wise by hand. Keep on turning until the needles are all the way up and the wire is held by the grippers. If the flywheel keeps on turning, the wire will stay in the grippers and the needles return to the “home” position. Remove any loose wires from the needle frame.

Twine-tie baler

Fill each compartment of the twine box with good quality twine (see Figure 1).

Follow the instructions in the opera­tor’s manual for that specific baler. When the first balls run out of twine, shift the remaining balls to the first po­sition and add two new balls of twine. Thread the twine, for each needle, through the guides and twine tension plate. Make sure that the twine is not crossed at any place.

Make sure that the twine runs over the guide at the end of the needle. When both strands of twine have been properly threaded, trip the bale measuring arm and turn the flywheel counter clockwise by hand. Continue turning the flywheel until the needles are all the way up, the twine is held in the twine disk, and the needles have returned to the “home” position.

Remove any loose pieces of twine from the needle frame. Connect the twine of the different balls together to ensure that when the one ball is finished, the next ball will continue supplying twine to the baler.

Drive train protection

Slip clutches are designed to prevent damage to the baler’s power system when the baler is overloaded. Adjust the slip clutch according to the manu­facturer’s recommendations. Exces­sive slippage occurs if the clutch is too loose, and wear on the clutch is rapid. Over-tightening the slip clutch elimi­nates the protection it was designed for. Some balers have shear bolts, or keys, instead of a slip clutch for power system protection. Use only the shear bolts recommended by the manufac­turer (see Figure 2).

Timing the feed rake

Correct timing allows the feed rake and needles to enter the bale cham­ber without being damaged by the plunger. Timing is usually controlled by the main drive chain, feeder drive chain and twister or knotter drive gears. If one or more of these parts are removed, the timing must be reset. Feeder teeth on the feed rake must leave the bale chamber before the plunger passes through to avoid seri­ous damage (see Figure 3)

Timing the needles

Needles must only enter the bale chamber when the plunger has com­pressed the hay and the plunger is therefore in the correct position. Needles and knotters may be damaged or broken if the timing is incorrect. Consult the baler operator’s manual for specific timing instructions.

Plunger head and knives

The plunger knife and stationary knife, must be sharp and adjusted to separate material in the bale chamber from ma­terial still in the feeder housing. Worn knives, or too much clearance between the knives will let some hay bend over the knife edges instead of being cut.

If the knives are sharp, the bales will be more uniform. The plunger guides and wear plates must be adjusted periodically to compensate for wear. If not aligned properly, the plunger could interfere with needle movement.

When sharpening stationary or plunger knives, maintain the original level and cutting angle on the blade edges to ensure efficient cutting. Set the clearance between knives by adjusting the plunger guides or tracks inside the bale chamber. The rollers on the plunger head can also be adjusted. Keep track wipers and scrapers in place to keep dirt and crop residue off the plunger tracks. Always measure knife clearance with a feeder gauge, and set an equal clearance along the full blade length.

Twine tension

To maintain uniform twine tension while the bale is being formed, adjust the tension control on the twine box (see Figure 4). Measure the force re­quired at the knotter assembly to pull twine from the twine box. The recom­mended force varies from 0,5 to 1 kg for plastic to as much as 6 kg for sisal twine (see Figure 5).

Planning and preparations

Moisture content

Crop moisture content at baling time affects a baler. Hay baled at a proper moisture content yields more nutrition and produces well-shaped, solid bales. When hay is baled too dry, leaves shatter easily. Wet hay can be baled, but the baler operates under excessive strain, because wet hay is difficult to push through the bale chamber.

Auxiliary equipment

Auxiliary haying equipment should be selected to complement the baling operation. Auxiliary equipment includes a power rake and tractor. Handling equipment is also needed to haul bales from the field to storage. Proper plan­ning and field layout will reduce labour.

Windrow preparation

Good windrow preparation reduces field losses and baling time. Windrows must not be too heavy, because the baler ground speed should be  tively fast and the windrow must not be wider than the baler pick-up. If windrows are too heavy, they block the pick-up. A well-formed windrow must have a uniform width and must be fed evenly into the baler to create bales of uniform density and shape.

Windrows should be loose enough for air to circulate because this will de­crease the chance for weather damage before the hay is baled. On average windrows are 0,2 m high and weigh from 2,0 to 4,0 kg/m.

Tractor preparation

Before the baler is hitched to the tractor, one must make sure that the tractor’s PTO speed matches the speed of the baler. Put the tractor’s drawbar in the recommended position and lock the drawbar parallel with the PTO drive shaft of the baler.

After the baler has been attached to the tractor, the baler hitch must be adjusted to keep the baler as level as possible. Attach the baler’s PTO shaft to the tractor’s PTO after the splines had been cleaned. Raise the hitch jack to the transport position (see Figure 6).

We thank the ARC Agricultural Engineering in South Africa who made the information on square balers available to the readers of ProAgri Zambia.

Next month we shall look at the field operation of balers. Visit www.arc.agric.za for more infor­mation.