With the widespread winterkill in many alfalfa fields and overall short hay supplies in many regions, putting up high-quality hay this season will be even more important than usual. One often overlooked piece of equipment, the rake, can play a critical role in ensuring all the hay is gathered and the dirt is left in the field, promising a quality end product. Whether using a wheel rake or rotary rake, there are a few adjustments to check this year to make sure everything is operating as it should be.
Regardless of rake type, one of the first steps is to make sure equipment is sized and matched to work together. Depending on the width of the mower or mower conditioner used, and the width of the windrow it created, some rake sizes and configurations will work better than others.
Tire inflation – Regardless of rake type, an adjustment commonly overlooked is tire inflation pressure. New rakes usually have a high tire pressure from shipping. Often, regulations or safety requirements call for a higher pressure during shipment. However, these high tire pressures can result in poor performance in the field and even cause premature machine wear and damage. If the rake seems to have excessive bounce in the field and is having difficulty maintaining proper ground contact, tire pressure is often too high. Consult the operator’s manual to determine the correct tire inflation pressure to ensure optimal performance and improve machine reliability and longevity.
Wheel rakes
Hitch – For wheel rakes, the first adjustment needs to happen when connecting to the tractor. The hitch is often adjustable to ensure the rake frame itself is level due to variations in tractor drawbar height from the ground.
Working width – Once the overall machine is connected to the tractor and level, the next adjustment is the working width. The working width should be set slightly wider than the distance between the outer edges of the swaths that will be raked together to allow for any inconsistencies in swath placement or varying over- or underlap during mowing.
A secondary adjustment that can affect working width is the rake beam angle. Often these two adjustments are linked together – the wider the working width, the greater the angle. There is generally a recommended range for the rake beam angle; if adjusted outside of this recommended zone, poor performance or machine damage can occur. Since the ground drives the rake wheels, an angle too wide or flat will result in the wheels not spinning well and may drag across the ground, potentially damaging the wheel or hubs. Too steep of an angle may limit the ability of the rake wheels to move crop effectively.
Windrow width – Another adjustment generally connected to the working width or rake beam angle adjustment is windrow width. The windrow width can play an important factor in drying times and varies widely depending on the quantity of crop, as well as the width of the pickup for the baler or chopper harvesting the crop. Widening the working width on many rakes often makes a wider windrow, since both rake beams move farther apart.
Additionally, increasing the rake beam angle also narrows the working width, since the rear rake wheels move closer together as the front wheels move farther apart due to the pivot being closer to the middle of the rake beam. Some rakes have an additional adjustment to set the windrow width independently from the working width, creating the desired windrow size regardless of working width settings.
Ground pressure – Once the working width, rake beam angle and windrow width are set, another important setting is the rake wheel ground pressure adjustment. The method of this adjustment varies widely depending on rake design but generally is changed by adjusting a spring or springs that control how much weight is carried by the rake wheels.
Some rakes use a spring to support the overall rake beam, while others have separate springs on each individual wheel arm. As a result, there can be between two and 12 springs to adjust on a 12-wheel rake. Since ground contact drives the rake wheels, it is important to have enough pressure so the wheels spin and effectively move crop. However, too much pressure can damage the crop, cause excessive wear on the wheels and increase ash contamination in the windrow. It is also important to note, ground speed can also affect raking performance. After adjusting wheel pressure, it is important to test the rake at a normal operating speed to confirm optimal performance.
Kicker wheel – Many wheel rakes have an optional center kicker wheel to turn the crop in the middle of the rake that would otherwise be untouched by the rake wheels. If the rake is equipped with one, it is also important to adjust the pressure on this wheel, or wheels, since it is generally a separate system from the rest of the rake wheels.
Rotary rakes
Rotary rakes function quite differently than wheel rakes since a PTO or, in some cases, hydraulics drive the rake.
Leveling – One of the first adjustments is the same as a wheel rake: When connecting to the tractor, adjust the hitch to level the frame. When using a rake connected to the drawbar, there may be a hitch adjustment, or the adjustment may be on the rake rotor itself. When connecting using the three-point arms, a check chain can prevent unwanted hitch height changes resulting from unintentional movement of three-point lift arms.
Depending on the rake type or configuration, each rotor may be capable of an individual leveling adjustment. Adjusting the wheels and their mounts under the rotor generally levels them from left to right. A separate adjustment may be available for adjusting the rotor pitch or level from front to back.
Working height – The next adjustment on a rotary rake after connecting to the tractor is to set the working height. Depending on the machine, height is set either hydraulically or with a hand crank to move the rotor up and down relative to the wheels. It is important to set the rotor low enough to ensure all the crop is gathered but not so low the tines contact the ground. Ground contact will result in machine wear, potential damage and the incorporation of excessive ash content in the windrow.
Windrow width – Windrow width on a rotary rake is adjustable as well. Depending on the configuration, moving a swath curtain in or out, relative to the rotor, sets the windrow width. On machines with multiple rotors, moving the rotors closer together or farther apart adjusts the resulting windrow width – note, this setting will also affect overall working width.
Whether using a wheel rake or a rotary rake, these adjustments can help you gather as much crop as possible while maintaining high-quality forage and limiting downtime. With a challenging hay season, proper settings and adjustments can help you improve your yield and forage quality. 
PHOTO: Whether using a rotary rake or a wheel rake, adjustments can help you gather as much crop as possible while also maintaining high-quality forage and limiting downtime. Photo provided by Kuhn North America.
Ben Craker is a senior product manager with Kuhn North America.
