CNC machine monitoring: what and how?

Evocon monitors a wide range of CNC (computer numerical control) machines from different manufacturers in metal and plastics processing.

Processes:

Lasers, plasma cutters, water jets, CNC lathes, milling and punching machines, and more.

Machine producers:

ESAB, Doosan, Okuma,  Haas, Fermat, Finnpower,  Amada, Bystronic, Feeler etc.

What can you monitor if you have a CNC machine?

In standard production processes single pieces are measured against a set target cycle time. In CNC processes it is usually difficult to measure the processing time of single units against the targets due to the wide range of custom orders and combinations of part layouts on raw material.

  • Monitoring effective work time (availability)
    The most common approach is to measure the operating time of the machines in comparison with planned production time. Planned production time is equal to scheduled works shifts where planned stops are deducted.This approach gives good insight into the utilisation rate of the equipment and stop reasons, e.g. loading, unloading, transporting material, cleaning, technical stops, breaks, organisational issues.
  • Counting pieces
    Depending on the machine and process it is possible to count the number of parts produced. In addition to effective work time this option enables to measure the processing time of a part against a set target time.

As the first step when starting to monitor machines, we recommend monitoring effective work time. The implementation process is faster and after some experience with the system it is possible to progress to counting pieces if it creates extra value.

How do you monitor a CNC machine with Evocon?

Monitoring CNC machine’s effective work time

To register when the machine is working the system needs to be connected to the machine’s spindle, laser, Andon light or other electrical circuit that has current going through during the processing cycle. This can be easily set up by local maintenance personnel with some assistance from Evocon, if needed.

Counting pieces produced by a CNC machine

The best way to count produced pieces is to configure the G-code of the machine. G-code can provide signals from the machine about the operational status (working in automatic mode or not working). In some cases, the code can be modified to send signals to a relay each time a part is finished.

The latest CNC machines have up to 4 relays that can be used as outputs for other devices. The signal from a relay can be read by the Evocon device and interpreted as a finished product.

Evaluating the performance of a CNC machine

  • When monitoring effective working time, it is possible to measure only the availability component of the OEE. Evocon’s Lineview would indicate processing time in green, and idle time in red colour.
  • When counting produced pieces, a target or ideal cycle time for each part must be defined in Evocon. The system compares this value to actual processing time for that part. Based on this data, performance (production speed during processing) is calculated and visualised.

Do you need an Evocon device to monitor CNC machines?

To connect machines using one of the methods described above, the Evocon device is needed to collect and send data to a server. However, it is possible to monitor CNC machines without the Evocon device. Some machines can be configured to send HTTPS requests directly to Evocon system.


If you have a CNC machine and would like to know more about how you could monitor it with an OEE software, please do not hesitate to contact us.