CNC 6040 Spindle Control

Note: This is only an on - off control there is no speed control due to limitations on the CNC control box , you set the speed using the potentiometer on the VFD (Variable Frequency Drive). To be able to control the spindle connected to the NowForever VFD Spindle drive , the following is required. The Parallel port pin used was P1 deduced from the YooCNC PCB silk-screen markings RLY - P1 , this pin controls the Relay on this board. The contacts of this relay were wired in to the terminals X1 and COM on the NowForever VFD , see photos below. The LinuxCNC settings were in Stepper Configuration Wizard -> Parallel Port Setup -> Outputs (PC to Mill) Pin 1: Spindle ON , this enables the control of the spindle. The Spindle on and off buttons will now work on the LinuxCNC Axis GUI.

The G Codes required for turning on the spindle are

M3 S1 

then delay 5 Seconds to allow spindle spin up

G4 P5.0 

and for turning spindle off.

M3 S0

For milling PCBs I added these g codes to the software FlatCAM Options Tab.

Prepend to G Code

M3 S1 
G4 P5.0

and Append to G Code

M3 S0

This then means when the G Code is generated from my PCB design at the beginning of the job the spindle will spin up wait 5.0 Seconds start milling and finally will stop the Spindle at the end of the job. This hopefully will reduce the wear on the spindle by only having it on when it is doing some milling.