Issues Affecting Tracking of Implements

The following information is provided by gps-Ag

Contact Fabian McLinden or Ben Malone at gps-Ag on ph (03) 5447 1777.

Please note that the file includes diagrams whereas they are not included in the information below (the text is the same) Issues Affecting Tracking of Implements (141kb .pdf)

  1. Drawbar length
    1. General rule of thumb drawbar length should be half the implement width.
      Eg 60ft implement needs a 30ft pull
    2. Longer drawbars give more leverage and better tracking.
  2. Width of Implement
    1. The wider the implement the worse the tracking because depth control and contour following capability is compromised as implements get wider.
    2. 50-60 ft implements challenge tracking.
  3. Depth Control
    1. Depth control across the implement is extremely important for good tracking, an implement that digs in more on one side than another will skew and track poorly
    2. Independent depth control tynes like parallelograms solve this problem.
  4. Tyne Layout
    1. Tyne layout is important in that we need to have an even tyne layout, the layout needs to be symmetrical around the centre of the machine.
    2. For example the lead tyne on the right side should be the same position on the left.
    3. This gives equal loading left and right to balance the machine.
  5. Terrain
    1. Undulating terrain and side slopes make accurate tracking more difficult
    2. Try to work up and down slopes not across slopes
    3. If working across slopes try to work in the same direction each time.
    4. Undulations and Gilgai formations often mean the implement does not maintain an even depth and hence the load on the implement is unbalanced and causes the implement to skew.
    5. Parallelogram / independent individual tynes alleviate this problem.
    6. Shorter drawbars are probably better if you are working on side slopes.
    7. If you have this type of country then narrower implements are better.
  6. Soil Type
    1. Heavy pulling situations are generally better than light loads because it is more difficult to pull the implement off course when it is under a heavy load.
  7. Following last years tracks
    1. In every situation the tyne/implement will try to follow the path of least resistance.
    2. Cutting across and old path will often cause the implement to follow in last years path.
    3. Make sure you have a wide headland so that you can clearly get straight tracking with the implement out of the ground before you lower the implement.
    4. Heavy soils often have a greater differential between last years and between the row tracking hence they have a greater tendency to track in last years row.
    5. Sandy soils the difference between pulling in last years row or between last years row is not great hence the implement should track better.
  8. Depth of implement
    1. By depth of implement I mean the distance from the front rank of tynes to the rear rank of tynes.
    2. Deeper implements will have a greater tendency to skew and follow last years rows.
    3. Deeper implements are inherently less stable because of variations in depth control.
  9. Wheels and Tyres
    1. Caster (free steering) wheels offer no lateral stability so are less stable
    2. Caster on the front on implements can often carry a lot of the load especially in heavy pulling situations (implements tend to rotate forward). So the rear tyres can carry little weight and so offer little stability.
    3. Wheels towards the front
    4. Tandem wheels offer more lateral stability than single wheels (lot more difficult to pull a tandem trailer around a sharp corner than it is a single axle trailer). Tandem axles want to run straight.
    5. Remember wheels at the front tend to carry most of the load and hence offer stability
  10. Seeder Box - Pull Behind v Pull Between
    1. We think that pull behind will be marginally better for accurate tracking rather than pull between. Pull behind means the implement is nearer the tractor and so more closely follows the tractor.
    2. Pull behind boxes can also load weight on the rear wheels of the implement aiding stability.
    3. Pull behind boxes with front and rear axles can sometimes have a lateral pull of their own and may pull the implement off course, make sure if the box has a front caster wheels that they are free to rotate.
  11. Previous passes
    1. The worse situation for tracking arises when you may have had some tracks that run in the general direction but say not very straight or slightly unaligned with this years row this often is the case if the farmer has swapped from one steering system to another or has been using marker arm and now wants to use autosteer.
    2. The implement runs for some time in last years mark, then eventually the run is far enough off line to jump out of last years run, the result is this is repeated up and down the paddock so you get a saw tooth type pattern created.
    3. What can be done about this?
      1. Cultivate the paddock to get rid of old marks?
      2. Work the paddock from a different direction – work at least 30 degree angle from previous marks.
      3. Ensure you have a very stable implement – narrow, balanced with long drawbar.
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