Key Considerations When Replacing Cotton Picker Doffers
As with any equipment, proper maintenance saves you money and hassle during harvest season. Checking things like head heights, pressure door settings, offers, and moisture systems can help you maintain high picking rates season after season.
A good way to check doffer height is by powering the row unit slowly and listening for a regular “thump, thump, thump.” When this happens, lowering the doffer column may improve doffing.
Spindles
As harvest approaches in cotton country, farmers are pulling their pickers into the shop for general maintenance like replacing worn doffers and moisture pads, adjusting doffer height, and generally making sure that they will operate as efficiently as possible. Taking the time to do these things helps ensure that you will collect accurate yield data.
During the harvest process, many different parts of the cotton picker are in constant contact with each other. This complex, high-precision machine requires skilled operator training to operate and precision shop equipment for repairs and adjustments. One area of the machine that is a vital contact point with the crop, and therefore prone to wear and tear from friction, is the cotton picker doffer.
The doffers (also known as lugs) on a cotton picker are designed to grip, hold, and pull seed cotton from the boll before it is spun into lint. They have sharp fronts to grab and grip cotton in a spinning motion and are held in place by a hard rubber disc. The rubber is tough enough to protect the doffers from damage and absorb shock loads, but it is also a flexible material that allows for smooth rotational contact between the lug and spindle.
Doffer lugs that are too tight can cause cracking or other forms of physical damage to the cotton. In addition, tightly worn doffers can decrease the efficiency of the picker and reduce yield. It is recommended that doffer lugs be replaced annually to prevent excessive wear and premature failure and that they should be made of rubber instead of metal to reduce maintenance and replacement costs.
If a doffer is worn or damaged, it can dislodge the row unit’s nut threads and cause them to rotate freely. This can lead to broken or non-rotating bar spindles and result in expensive repairs.
Check the nut threads for damage and tightness, especially on left-hand spindles. Replace worn or corroded nuts, and be sure the new ones match the nut thread on the row-unit shaft. Also, be sure the doffer lugs are the correct length to fit the groove on the doffer bar shaft. Also, if the doffer lugs have rounded edges from wear, they may also not grip and pull cotton.
Bushings
As with any mechanical device, there are parts of the cotton picker that wear out faster than others. It is important to ensure you get quality replacement parts from a trusted supplier so your equipment lasts for as long as possible.
A key to maximizing your cotton picker’s lifespan is to perform regular inspections. Understanding the common wear points will help you identify issues before they escalate into costly repairs and lost productivity.
Spindle bushings are a major component of the cotton picker’s lint-separating mechanism. They are rotating cylinders that hold the spindles, which snatch open cotton bolls from the plant and separate them from their stalks. The bushings also hold the studs that extend from the spindles, which grip and remove lint. Over time, lubrication may dry out, increasing friction and causing the studs to bend and deform. If this happens, the studs may slip off the cylinder and break.
If you are replacing cotton picker doffers, using the correct size and type is important. The wrong size or type of doffer could cause damage to other components, such as the spindles and moisture system columns. The doffer lugs should be made of flexible material to allow the bolls to pass through and prevent sand, trash, or debris from contaminating the lint.
Another important consideration when replacing cotton picker doffers is ensuring that they are properly adjusted to the proper height. This is done by listening to a consistent thump of the bar against the floor or using a stethoscope to listen for a sound that is repeated at regularly spaced intervals as the bar passes under the doffer column. This will indicate that the doffer height is incorrect.
Other important aspects of a cotton picker that must be kept in good working condition are the row unit and the pick-unit cabinet. The row-unit is a claw-like fixture that funnels the cotton plant into the picking zone of the machine. The cotton spindle bushings are within the row unit’s depths, which hold the cotton-picking spindles. The cotton picker cabinet contains a variety of other components, including the pick-unit motor and a computer control panel that monitors the operation of the machine.
Moistener Pads
A cotton picker is a machine that harvests cotton from plants. It uses a rotating spindle that removes the cotton seeds from the plant, and then a counter-rotating doffer catches the seeds and blows them into a basket for storage in a module builder. The material is then transported to a gin, which is washed, graded, and prepared for shipment as a standard bale. 3 primary components are key to the operation of a cotton picker: the doffer, the spindle, and the moistener pad.
Many commercially available cotton pickers include one or more rotary drums carrying a plurality of picker spindles. These spindles are first rotated through a moistening station where the moistener pads moisten them, then through a pick-off station where a doffer assembly removes the cotton from these spindles.
The present invention provides a moistener assembly that includes a plurality of moistening members mounted in a cantilever fashion on an elongated support. Each of these moistening members comprises a mounting arm, generally of aluminum, secured to the support, and a moisture-retaining pad removably received on the mounting arm. The structure of each of these moistening members substantially reduces the probability that the mounting arm or the moistener pad will break upon engagement with a solid object such as a stone or a rock.
This type of construction also simplifies the initial attachment of each moistener member to the moisture-retaining pad, and it facilitates their removal or reattachment to the moisture-retaining pad for cleaning, repair, or maintenance purposes. Additionally, the arrangement of each of these moistener members greatly facilitates their subsequent movement with respect to one another when engaged with a rotating cotton picker.
Regular inspection and maintenance of the cotton picker’s various parts ensure that it will perform well throughout the harvest season. This maintenance must be done to prevent breakdowns, fires, and other potential hazards that can occur when equipment is not properly maintained. Other important components to check or replace are the miscellaneous lights, harnesses, tires, rims, wheel locks, handholds, ROPS, and hydraulic cylinders.
Doffers
The doffers in your cotton picker are important to the machine’s operation. They must be flexible enough to allow seed cotton, trash, and other material to pass through without jamming or causing damage to the spindles. Weather, sun, and use over time can harden doffer lugs and reduce their flexibility. We recommend regularly monitoring them and replacing any that have lost their flexibility.
Conventional mechanical cotton pickers comprise rotating heads, each set on a vertical axis and carrying a series of radially extending, rotated picking spindles that pass open cotton bolls on the plant and pick the exposed cotton from the plants by means of slight barbing or roughening of the spindle surfaces. The spinning cotton-bearing spindles then pass through doffer means which remove the picked cotton from the spindles by wiping.
Each doffer in the dofng means is provided with a pair of clamping members having end portions arranged in an overlapping relationship to one another, and common securing means extending through the overlapped end portions and the plate to secure the doffer in place. The doffer is then mounted on the shaft such that it extends vertically from the plate and is located at a distance corresponding to the spacing of the series or layers of the spindles from which the cotton must be removed.
These doffers are made of a superior quality polyurethane material that offers long wear life and high durability. They are also designed to effectively remove seed cotton from the spindles of your cotton picker using a stripping motion and can help you increase your yield.
