Loss of machine motion smoothnes – what are the reasons?

Read the article and find out what are the most common reason of machine motion smoothness loss.

„LookAhead Lines” Low value

This value stands for number of G code lines analyzed by Mach3 in advance. „LookAhead Lines” maximum value depends on computer performance. More information you can find here:

Work of a machine in Exact Stop mode instead of Constant Velocity “CV” mode

Information about Constant Velocity “CV” configuration can be found here:

Ethernet transmission disruption

It usually happens in plasma cutters. In this case it’s suggested to use 6th category Ethernet cable, to assure proper signal wires shielding and machine’s ground. Disruptions influence on Ethernet transmission can be seen when „Trajectory buffor” value in PlugIn Control \ CSMIO_IP plugin \ General info is close to 0.

Maximum input frequency of drive’s STEP signal

Sometimes happens that cheap servo and stepper drives constructions can’t work with higher than 70 – 100kHz frequency of STEP signal. Hence position lost and unstable motor’s work. That is why before you purchase servo or stepper drive it’s recommended to find out more about its documentation or contact the manufacturer.

Computer performance

Low computer performance may cause lack of machine’s motion smoothness, especially when G code is very long and consisted of very short lengths. In such cases it’s recommended to turn off the tool patch preview „Diagnostics (Alt-7) \ TollPath on/off”, which uses large computer resources. In extreme cases it’s recommended to replace the computer for another one having higher performance.


18 June 2016