Powering the motion controller together with the PC.

[Tweakie.CNC]

Something that may be of interest to others…

I constructed my initial engraving / laser machine some 20 years ago running with Mach3 and the PC’s LPT parallel port. Before the days of the ‘charge pump’ it was necessary to have the PC software up and running before the CNC machine was powered up and I still stick to this method today on my more recent machines.
Each of my CNC machines is powered through an electromagnetic contactor which enables me to not only use the software polled ESTOP but it also gives me an EMERGENCY STOP where the contactor can be tripped, at the touch of a button, enabling all power to the CNC machine, laser, spindle, etc. to be disconnected (if ever required) leaving the PC and associated motion controller, which is powered separately, running as normal.
In order to power up my motion controller and PC together I use a Solid State Relay which is energised by one of the PC’s USB ports. The SSR then, in turn, energises the PSU powering the motion controller. It is really quite a simple system which, for me, works just the way I want it to.
Nowadays all my machines run under UCCNC software but, as mentioned previously, I still power up the PC and have the software up and running correctly before I turn on my CNC machine.

Tweakie.