Posted: 02:09am 13 Jul 2024 Copy link to clipboard
OA47 Guru
I have a homebuilt 40cm X 30cm CNC machine and I would like to implement an Automatic Tool Changing sequence. I am using an ER16 tool holder on an 850W spindle controlled by a 3 Axis CNC GRBL 1.1 Controller Board. I have a working GCODE macro to load an empty spindle with 1 of 4 tools by moving to the appropriate location lowering to the tool and at low speed spinning the spindle to thread on the ER16 collet.
The issue I have is in the tool release macro as the controller does not support reverse direction of the spindle to release the ER16 collet.
Can anyone come up with an idea of how I can get the spindle to reverse in code without having to change out the Controller Board.
Hoping this all makes sense. 0A47
Posted: 05:04am 13 Jul 2024 Copy link to clipboard
SimpleSafeName Guru
There's probably an easier way to do this, but reversing the spindle amounts to swapping two wires (be it AC, DC, or a stepper). You can do this using an output from your controller to an external relay or two.
Posted: 05:34am 13 Jul 2024 Copy link to clipboard
OA47 Guru
SimpleSafeName, the gcode M3 M4 & M5 are normally used to operate the spindle CW , ACW and STOP but the dc output from the controller does not invert. I use this output to operate a relay which in turn operates the 120V DC supply to the spindle.
