Potentiometric head pressure on boom mowers – Facts and myths
In the world of municipal machinery, there is increasing talk about the so-called potentiometric head pressure system in boom mowers. Some manufacturers try to present this system as a revolutionary solution. In reality it is an unnecessary gadget that can cause more harm than good.
What is potentiometric head pressure?
Potentiometric head pressure allows the operator to regulate the force with which the boom mower head presses against the ground. Sounds like an innovation? In practice it is a system that does not improve work efficiency and only complicates operation.
How does potentiometric head pressure work?
System ten opiera się na zaworze sterowanym potencjometrem lub manualnym, który kontroluje przepływ oleju hydraulicznego do siłownika ramienia – pierwszego lub głównego. Teoretycznie pozwala to na dostosowanie nacisku głowicy do różnych warunków terenowych. W rzeczywistości jednak operatorzy często ignorują tę funkcję, skupiając się na podstawowych ustawieniach zapewniających stabilność pracy.
Why is potentiometric head pressure an unnecessary gadget?
• Applying potentiometric pressure to the main arm by introducing double-acting hydraulics to the main cylinder opens the possibility of mounting an excavator bucket, effectively turning the boom mower into an excavator. However, this solution creates the risk of damaging both the tractor suspension and the mower itself, which has already happened in practice. It should be remembered that potentiometric control valves are used mainly in mini-excavators and excavators – not in boom mowers.
• No real impact on work efficiency – boom flail mower operators do not need extra settings that only distract them.
• Increased risk of damage – the system can lead to cylinder deformation and hydraulic failures.
• Unnecessary complexity of operation – professional operators prefer simple, reliable solutions.
In addition, applying potentiometric pressure to the main arm by introducing double-acting hydraulics to the main cylinder opens the possibility of mounting an excavator bucket, effectively turning the boom mower into an excavator. However, this solution creates the risk of damaging the tractor’s rear suspension as well as the arm itself, which has already happened in practice. It must be remembered that potentiometric valves are used mainly in mini-excavators and excavators – not in municipal machinery.
Potentiometric pressure and structural durability
Unlike excavators, boom mowers are not designed to transfer large pressure forces. Overloading the arm leads to faster component wear, which results in higher service costs and the risk of downtime. In extreme cases, when the entire weight of the head, boom and partially the tractor rests on the arm, it can destroy the boom mower. The arm can be bent, twisted or even broken.
Chinese control valves in the hydraulic system – great marketing, disastrous practicality
A very important aspect of this technology is the fact that in many cases the hydraulic control valves used are identical to those used in Chinese mini-excavators. These valves differ practically nothing from hydraulic systems used in Chinese mini-excavators and represent a cheap alternative to dedicated boom-mower control valves.
Why does this matter?
• Economy – using Chinese valves saves costs compared to more expensive specialized solutions.
• No gravity drop – unlike professional boom mowers where the arm descends by gravity, a double-acting cylinder is used here, similar to Chinese excavators.
• Clever use of valve specifics – the solution is very well packaged in marketing terms, because on paper it looks like a well thought-out technological improvement. In reality it is just a clever marketing move that relies on a simple use of cheap components.
This solution is effective only in Chinese mini-excavators, where it was developed for entirely different applications. In boom mowers it does not improve performance – on the contrary, it can lead to breakdowns and increased component wear. It is not a practical or safe solution – it is pure marketing.
A real-life example: What can go wrong?
This year we encountered a case that perfectly illustrates why potentiometric pressure is a bad idea. One of the companies promoting this system delivered a machine in a public tender to a district road authority (PZD) in Silesia. The operator, unaware of the limitations of the system, rested the arm on the head. What happened?
The cylinder bent in the opposite direction – literally like a banana. The “importer” – in reality a small gas station – tried to blame the operator. In truth it was not human error, but a flawed system concept.
How do we handle this at ROLMEX?
At ROLMEX Karol Misiuda we know the potentiometric pressure system well. We offer it and can install it in any machine – both in standard configuration and on special customer request.
But do we recommend it? Absolutely not.
Our machines are designed with the real needs of users in mind, not to meet artificial tender requirements.
Why are our boom flail mowers better?
Our machines work in 25 countries around the world. They are durable, versatile and reliable in the most demanding conditions.
• Durable construction
• Versatile arm configurations
• Reliability in the toughest conditions – in forestry, railways and land drainage
Exports to 25 countries – global ROLMEX quality
Our boom mowers are recognized not only in Poland, but also in 25 countries around the world.
Nowhere is potentiometric pressure considered something necessary. It is simply an unnecessary add-on that contributes nothing to the quality of work.
Conclusion: What really counts?
In the world of municipal machinery, gimmicks are not what matters.
What counts is reliability, ease of operation and durability.
Potentiometric head pressure? We have it. We offer it. But we do not recommend it.
We know it is an unnecessary gadget that brings nothing to day-to-day work.