On 2010-12-02, Pete C. wrote:

Ignoramus24652 wrote:

On 2010-12-02, DoN. Nichols wrote:

Just out of curiosity -- does it perhaps need compressed air to
release the Z-axis brake? Make sure that you are supplying it with
everything that it needs.

On my mill, no air means brake not applied.

i

They're talking Z axis brake, not spindle brake.

On machines that have them, Z axis brakes are normally of the
power/air/hydraulic to release i.e. fail-safe variety to endure the
heavy machine head doesn't crash into the table/part/vise/fixture on
power down. Small machines with Z quills don't have Z brakes since they
don't have enough weight to cause the Z ballscrew to back drive when the
servo is off.

Spindle brakes don't usually exist on larger machines with servo
spindles and ATCs since they aren't needed. The spindle servo handles
braking and spindle orient just fine, and the power drawbar is a spring
loaded (belville washer stack) hydraulically operated setup that doesn't
impart any rotational force when operating.

I see. Thanks. In another life, I may want to be a CNC programmer or
something of that sort.


i