Re: [CAD_CAM_EDM_DRO] Re: E-Stop Revisited (PS on sherline auto changer)

ballendo wrote:

>James,
>
>With servos you should short the leads so the motor "brakes"...
>
>
>

Not necessarily. This may work OK on small machines with small motors,
but could
do a lot of damage on larger machines. A braking resistor is a much
better way of
doing it. You might calculate the value such that at the DC bus
voltage, it will draw
about the rated motor current. A dead short could draw so much current
as to damage
the magnets in the motor, break belts or couplings, twist leadscrews, etc.

In most systems, you can apply the resistor to the DC power input
terminals to the
servo amp, and the freewheeling diodes will direct current from the
motor to the
resistor.

Jon