CNC Machine Installation Measurement – How to Do It Right
16.09.2023
Metecno’s portal MeteCNC® Machine Tool represents the pinnacle of mechanical engineering. Weighing 13 000 kilos, this CNC machine is a engineering masterpiece that sets high standards not only for manufacturing but also for its installation measurement.
That is why we are the right people to answer one of the most important questions in machine building: How do we as a machine builder ensure that a massive machine tool and others similar to it are installed on the floor in the manner required for the machining accuracy of the machine?
The location of the machine is everything
Before the actual installation, we need to examine carefully the location of the machine and the surrounding infrastructure. Especially the status of the floor, but also the bearing capacity of the subsoil layers is of great importance.
The floor must meet the two most important requirements: the floor must be thick so that it does not bend at all when the massive machine tool moves back and forth. There must also be enough mass in the floor, because mass kills vibration.
The floor must withstand not only the static weight of the machine, but also the dynamic loads it causes. An uneven floor creates a weak base for the installation of a precision machine tool, which brings significant additional challenges. The idea that the problems brought by the floor could later be compensated mechanically or programmatically should be forgotten.
In practice, any factory already makes a decision when casting the floor, how massive machine tools they can be sensibly use on the floor in the future. In ideal cases, a separate entity of its own is poured into the floor, where the machine is installed, and in this case the vibration of the environment cannot affect the operation of the machine.
Metecno uses Renishaw XK10 measuring laser system to help with installation
At Metecno Oy we use the Renishaw XK10 to ensure accurate and reliable measurement results.
Its optics and electronics work seamlessly together, enabling accurate measurements. With the help of this system, it is possible to carry out the most important measurements for devices such as CNC machine tools.
These include flatness, straightness and parallelism measurements.
Start from a geometric position
The first step is to check the geometric position of the machine by measuring.
This step includes checking the horizontality of the machine, the alignment of the axes and the mechanical correction and rechecking of any errors.
When checking the initial situation, it is also important to consider the correctness of the connection between the machine and its environment.
Perpendicularity check
Perpendicularity measurement is certainly one of the most critical stages of installation measurement.
When we talk about perpendicularity, we are not referring to just one measurement, but the combined result of several measurements. Each axis, be it X, Y or Z, must be mechanically as perpendicular as possible to each other. In this way, we can create an excellent basis for compensating the perpendicularity of the axes programmatically, if necessary.
To ensure this, we need tools such as laser measuring devices, which are able to measure deviations with an accuracy of hundredths of a millimeter, sometimes even thousandth of a millimeter. Axes installed perpendicular to each other ensure that the movements of the machine meet the customer’s requirements and are easy to programmatically compensate if necessary.
With the help of the obtained measurement data, we can then conclude whether we can correct programmatically or mechanically possible deviations . As one example, we have to take in to account the perpendicularity of the milling spindle in relation to the movement axes. If the perpendicularity is not good, it leaves cutting marks on the workpiece, which in turn weakens the surface quality of the workpieces.
“After all, the measurement is always carried out by a human being. The measurer must have a clear vision of what is being measured, the results of the measurement and their impact on other things.”
CNC machine installation measurement is a complex entity
In general machine installation measurement is not a straightforward, simple process.
You need to perform every measurement, adjustment and correction very carefully, and the measurer must set himself up and reserve time for checking the measurements as well. All this because the most important feature of the machine, the accuracy, depends on these measures.
In addition, environmental factors such as temperature, humidity, noise and vibration (and especially their changes during the measurement) affect the measurements. For this reason, we have to monitor monitored and take into account throughout the process.
Linear conductors are one concrete example of precision challenges. Milling machines have linear guides on each axis to move the machine. If mistakes would happen during the installation, the positions of the conductors could deviate from the required installation tolerances for them. The inaccuracy might not necessarily reflect the quality of the workpiece, but it could significantly shorten the service life of the wires.
After all the geometric and kinematic adjustments have been made, the validation of the machine is performed in several different stages. Firstly, dynamic tests, where the machine’s speed, acceleration and braking are tested, ensure that all mechatronic components work together seamlessly. After this, several accuracy tests are performed, where the performance of the machine is compared to the tolerances stated by the manufacturer.
Remember these
Installation measurement is a truly critical process that ensures optimal operation of the CNC machine tool.
Since the process is complex and time-consuming, you cannot choose just anyone to do it. If performed correctly, installation measurement guarantees high-quality production and a long service life for the machine.
The suitability of the measuring devices used in the measurements is also of great importance. With the wrong measuring devices, it becomes difficult or even impossible to reach your goals. Therefore, in order to obtain reliable data from a measuring device, the measuring devices must be in good condition and calibrated.
Follow-up of the CNC machine installation measurement
When you have done the initial installation and adjustment work, you should not heave a sigh of relief – the process doesn’t end there.
There may be a need for retrospective measurements due to various events. Such events include, for example, the collision of a machine, replacement of movement components, or observations of quality problems in the workpieces being processed.
Says mechanical designer
Measuring the installation of a high-quality CNC machine tool is not an easy task, but with the right tools and a professional team, it is possible.
Even though technology offers the tools and opportunities for extremely accurate measurement and adjustment work, the skill and experience of a machine builder are invaluable. Optimum installation of the machine combines the advantages offered by technology and the engineer’s ability to identify potential problems and find solutions to them.
This combination ensures the ideal operation of the machine. To put it in a nutshell, a careful installation measurement process enables production to have a suitable and functional machine that will serve for decades.
Considering the complexity of a CNC-controlled machine tool and the possibilities it offers, it is no exaggeration to say that its installation and measurement are almost as important as the manufacture of the machine itself.
For more details
If you have any additional questions from our blog or if you need a consultation on the installation measurement of a full-blooded CNC machine, contact us: info@metecno.fi