Near Intersection of I-35 & I-90 Southern Mn. | I believe we have the same setup. That is a Hagie STS-12 with PWM pump control being run with an Ag Leader Liquid Product Control module.
In some respects I'm not understanding your problem. I believe you are concerned about the observed pressure spike when the booms first turn on (full section). This seems to spike but quickly returns to the usual pressure for that speed, tips and rate. I guess I don't see this as a terrible problem.
The temporary pressure spike would seem unnecessary but I doubt that it reflects a major change in applied rate for that short period of time. Remember to double the output through most tips requires that the pressure be squared. In loose terms this means that the tips are self-limiting in a practical sense.
I notice you compare this rig to an NTB. I'm not certain what NTB refers to.
Also remember that a pump control setup such as your Hagie has, could be a Servo type or a PWM type. My older STS-10 used a Servo type hydraulic valve to control the pump speed and thus the applied rate. My current somewhat newer STS-12 uses a PWM type hydraulic valve to control the pump speed and thus the applied rate.
The Ag Leader configuration allows the operator to choose which type of control they are using. This needs to be chosen correctly.
I traded my STS-10 with the Servo valve back to the dealer from whom I had purchased it. I removed the Ag Leader modules and reinstalled them into the somewhat newer STS-12 which uses a PWM valve. I needed to create a new configuration completely from scratch due to the number of boom sections, measurements etc. I needed to choose the PWM type of control rather than the Servo Control I had used with the previous STS-10.
I made a mistake in the setup and did NOT choose HOLD as to the question of what to do when all sections are shut off. That meant that when turning around for a new pass, the PWM valve essentially shut down considerably. This meant there was little or no agitation while turning around (probably not too serious). The serious part was that the pump was running very slowly and when application resumed, the initial pressure was very low resulting in under application. The applied rate did "catch up" but by then the sprayer had covered a fair distance.
One approach would have been to gradually speed up, allowing the system more time (cover less distance) as the system "caught up". The proper approach was to set the control valve setting to HOLD. This means that the pressure while turning around will be maintained at that PWM setting. This provides agitation and means the system will "start" applying at that level when the booms come back ON. This value could be somewhat "too high" or somewhat "too low". In either case it would be closer to what was needed.
OK, so we could set the HOLD value at a certain PWM value but what value to use? We observed the PWM value that the system was using for spraying at the typical rate and ground speed. We used this value as a starting point.
If your flow meters are working properly, I don't believe changing them would have any effect.
Another poster suggests increasing the lead time for the valves to open under auto swath. This would change the time/place where the booms are turned ON for auto swath but I would think that your pressure concerns would remain the same, just occur a second later.
Edited by tedbear 5/31/2026 08:01
|
Ag leader direct command help
