Know Issues

Error error: lto-wrapper failed during verify or upload

This is a known GCC compiler issue in some Arduino boards versions like "Arduino AVR boards version 1.6.23" Downgrading the boards version to 1.6.22 or upgrade to Arduino version 1.8.10 will solve the problem.

RPM measurements

RPM measurement measurements are influenced by the receive of false index pulses, most likely due to electronic noise. If you experience these kind of problems, activate the spindle index and synchronization pulse debouncing (grbl setting $41, Mega board only). Set it to a value of 250 tics (1 ms) and experiment to find the lowest value that eliminates the problems. Finally increase that value by 50%.

Sudden shifts in threads

Threading uses spindle synchronization pulses to keep the Z-axis in sync with the spindle. The receive of a false synchronization pulse will lead to a sudden shift in the thread turned. False pulses are most likely due to electronic noise. If you experience these kind of problems, activate the spindle index and synchronization pulse debouncing (grbl setting $41, Mega board only). Set it to a value of 250 tics (1 ms) and experiment to find the lowest value that eliminates the problems. Finally increase that value by 50%.