Practical

Pro Operator masterclass

Modern sprayer terminals can help deliver incredible accuracy but, like any system, you only get out what you put in. Chafer’s Ben Bryant explains how to diagnose and rectify some of the most common digital issues. Words and images by Ken Topham.

There can be few operators who have not faced a time when the ‘computer says no’. Sometimes this can be caused by something as simple as a clogged filter, driving too fast, slow or simply a mistake in inputting data.

If this happens on a Chafer you will usually end up talking to Ben Bryant and, because it fits a wide range of terminals, he has a wide experience of different systems. Most problems, he says, are often not caused by anything wrong with the terminal and not usually restricted to any specific make or model.

Here we look at John Deere 4640, which is a common fitment to many machines. Although other screens and rate controllers aren’t exactly same, they do have common setting issues and it’s often the terminology that trips people up.

This particular terminal is fitted to a Chafer sprayer with 32m wide boom, 32 sections and uses an Ag Leader rate controller. GPS positioning is delivered through a StarFire 6000 receiver. The farm runs a fleet of John Deere tractors, so using this system made sense, enabling the farm to phase out paper spray recs, and send data via the John Deere Operations Center.

Most common problems are usually quite simple, often related to the GPS and shut-off and can be easily remedied. Other issues may require finer control over how the rate controller reacts to speed that can need adjusting to suit the crop or other requirements.

It is also important to check the machine’s geometry after making adjustments or changing equipment. One way to prevent problems is to keep a record of the base settings before adjusting and make a note of any changes – what has been adjusted and why. For example, overlaps for a different chemical to prevent scorching.

Ben advises annually checking settings and fine tuning the system – ideally as part of a service.

Saving data

Although it is possible to save profiles to an external drive like a USB, one of the best ways to avoid losing settings is to take pictures of them, advises Ben “It’s not common, but it can happen that you lose a profile if the system is updated and your previous settings may not be compatible.” Saving the pictures on your mobile means you can quickly access them in the future. Similarly, it’s a good idea to record short videos of seldom-used features and ones that aren’t often changed. Record yourself going through the procedure – it can save a lot of time when you need it.

Only water

It’s easy to get hung up on a 1% or 2% inaccuracy issue but, Ben says most of what a sprayer applies is water. “It’s the chemical application that’s important, this can be down to very small amounts of actual product – so, it’s better to be very accurate and when filling, rather than working about a 1% overall application error,” he explains.

Useful home screen

Rate control is a good page to display during spraying because it provides a good overview of all the key settings and is the best starting place to look for problems. As well as displaying target rate, applied rate and operating sections, this page also provides information on the field and a small GPS window. With section control shown in the centre, operators can quickly see if they are on and off and check whether they should be.

Track GPS status

The GPS page can help with tracing problems, BUT it needs the right information from the operator to do this. Each individual field should be mapped, boundaries recorded and data stored. This is useful information if, for example, you need to spray a headland last. Also, sprayers can work from an older field map for headland shut off. This also makes it easier to find application problems – precisely tracking down where something went wrong. The ‘counters’ (left) should be reset for every field.

Check valve response

If, when forward speed changes, the rate is erratic or the machine is struggling to maintain the set application rate, check on the ‘Control Valves Settings’ page. Valve Response 1 is for a quick reaction when the rate is way off target, while Valve Response 2 provides finer control for when the application is closer to the target rate. ‘Threshold’ is the point where it changes between the two values. Smoother and consistent driving will help, but if the pressure remains erratic it may be because the system is still over-compensating and needs adjustment.

Key settings

‘Implement profile’ is a key settings page. It should only require adjusting if something physical has changed on the sprayer – such as if the receiver position or the boom/applicator outlet has been moved fore or aft in relation to the receiver. The system must know exactly where the components are positioned, otherwise there will be off/on issues, possibly leading to inconsistent overlaps. It’s particularly important for trailed machines, which may by used with different tractors and the receiver position may differ.

Mechanical Delay

Part of the implement profile, ‘Mechanical Delay’ is the time allowance for the fluid to travel between every component – from the shut-off valves to the nozzles. This is because the system’s ‘mechanical delay’ needs to know how long it takes to travel in the pipes, as well as switching times. Although this may appear a bit over the top, all these delays add up, and if not accounted for it could result in application misses or scorching due to overlaps.

Section Control

Most operators will need to occasionally adjust the overlap settings, depending on the section widths. Sometimes it may be necessary to under-lap and avoid the risk of scorching the crop or need to be adjusted when operating near to sensitive boundaries. The section control can also be disabled here if required – whether you work with internal or external boundaries. And, if you have a GPS issue and need to finish a field, it could be a useful ‘hack’.

Receiver position

Like others, Chafer fits many different manufacturers’ receivers and fabricates brackets to suit. If, however, you change receiver brand or need to modify the bracket in any way that will change the unit’s position this will have to be accounted for in the settings. There are compensation settings to accommodate any receiver position changes. Also, if you remove or swap receivers, it’s a good idea to make a note which one is connected to the sprayer.

Check the geometry

Despite making adjustments to high technology, a tape measure is still a valuable tool. It’s essential for checking exactly where everything is positioned in relation to the receiver. It’s key to get the correct geometry dialled into the system. This is critical because it needs to know where the application boom is in relation to the receiver. This enables it to accurately identify the boundaries to help reduce discrepancies in shut-off and overlap settings.

Assess the offset

GPS settings shouldn’t change, but it’s worth making a note of these if you’ve had a firmware update or change, or if you are likely to alter any of the GPS connected components. All of the parameters are equally critical and, if incorrect, will impact the sprayer’s shut-off timing and overlap. Obviously, this self-propelled machine doesn’t need an input for drawbar length, but it’s worth remembering for trailed sprayers.

Do’s and Don’ts

These are the top ten questions most commonly received by Ben Bryant or one of his product support colleagues. They can often fix most over the phone. Usually it’s the simple things that can cause the biggest headaches, but most are not too difficult to solve.

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