Re: Safe Spindle Control

> A lot depends on your faith in electronic devices. etc...

> there is a power supply running through your step/direction
>controller (steppers) and a power cord leading to your spindle. tie
>those power lines to a big mushroom emergency switch mounted
>somewhere conviente on your table. this will allow the computer
>systems and peripherials to initialize and talk to each other without
>allowing the power to make it to the buisness end (motors and cutting
>tools).

This is something I have worried about ever since I rebuilt my CNC
Bridgeport. Each time I change a tool, I wonder if the spindle could
somehow start up. Is this really a possibility? The tool change is
usually done during an M6 command and the computer is waiting for
cycle start button to be pushed.

Where would the best place be to place a switch to disable the spindle
motor? I assume it would be on the 3 legs of the 3phase power as it
comes into the motor? There would have to be a second switch for the
AC 110 that would disable the power to the DC powersupply that runs
the stepper motors too. I imagine opening the normally closed switch
during a tool change, then closing it before proceeding. Would I have
to have 2 separate switches or is there a way to use just one?

Thanks guys for bringing this up!

Keith Clark