Measuring the Accuracy of a Water Jet Cutting Machine

A water jet cutting machine is popularly employed in many industries that delivers a high level of precision and accuracy. The machine is also capable of virtually cutting any type of material with only few limitations.

So, what really is the real accuracy to be achieved with a water jet machine?

The machine’s precision when it comes to cutting is greatly dependent on the following: the cutting power, machine’s condition, its included parameters (S, M, P, Q, X), thickness of the material and its type, and temperature. But, as a rule of thumb, the value that can be achieved using water jet in terms of cutting precision should be ≥±0.05 [mm].

Additional numbers are as follows:

  •         Inside radius is 0.4 [mm]
  •         hole diameter should be 1.0 [mm]
  •         Kerf width should be at 0.8 … 1.2 [mm]
  •         Range of thickness: 0.01 … 1.2 [mm]
  •         Roughness measurement Ra: 3.2 … 50 µm
  •         Angular error for its cut edge: ≥0.02 [mm]
  •         Contour error should be ≥0.25 [mm]

In the case of the accuracy of the finished parts using a water jet cutting machine, they will involve a combination of machine accuracy (direction XY) and process error (waterjet), as well as workpiece stability.

The machine’s mechanical precision is greater than the precision of its parts. Its positioning accuracy will be determined by the DXF file and a software.


What Factors Affect Its Precision?

The measurement accuracy and surface quality of a workpiece that is cut with the basically depends on the kind of material being processed, the thickness, its cutting parameters, like type, pressure, and abrasive, feed rate, nozzle combinations, as well clearance from material, process control and others. Moreover, the condition and age of parts like the nozzle, dynamics and precision of the machine are all of great importance.

For you to achieve tolerances for the parts, below are the conditions that should be met:

  •         Using original parts only from the manufacturer
  •         Optimized cutting results
  •         Thickness, type, and dimensions of the material
  •         Feed rate
  •     Workpiece sheet heating will have a negative impact on its accuracy, even on ambient temperature and heating-up tank.
  •         Abrasive amount and type
  •         Nozzle clearance
  •         Fluctuations of the pressure
  •         Condition of the waterjet machine
  •         The roughness of the surface should not affect the measurement
  •         The measurements should not be administered at the contour (lead-in / lead-out)
  •         Analysis and measurement method to VDI/DGQ 3441

There is really no question when it comes to the benefits that can be delivered by a waterjet machine. This must also be the reason why it has become a valuable tool in many applications. With this, the way how people do and finish their work has greatly change. We just can’t wait to see more of these benefits.