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What's a better setup? Installing a braking resistor to a Hitachi WJ200 series drives to stop the spindle quickly or would letting the spindle brake stop the spindle after say a half second of shutdown?
How did Bridgeport set it up initially? I've never seen it run before my retrofit and I know it had an auto setting I'm just not sure that going from 4000 RPM to 0 RPM quickly is good for the spindle brake or even the motor for that matter. It's a Bridgeport Boss 5 with a rigid ram.
Original control for the brake was very simple. When either the MF OR MR relay was activated (forward and reverse relays) the small contacts on the top of the relay , would change state from normally open to normally closed or visa versa. These contacts would then be connected to the brake solenoid to deactivate solenoid when the spindle is turned off. The brake is applied when the solenoid is not active as this allows the spindle to be locked for tool changes. These small contacts are used for the flood / mist control to shut off when spindle turns off.
As an original system, the brake is able to stop the spindle from turning very quickly as long as air pressure is above 80psi.
If you use a mechanical brake with your VFD, and you don't have a breaking resistor, you will trip out on OL. You may trip it out just changing speeds fast if your using the mechanical belt speed adjuster.
use both
on my BP I use a brake resistor to stop the spindle and use the VFD relay output to engage the spindle brake. I delayed the RO around 4 seconds, which is about double the time my spindle takes to stop from top rpm
I had the resistive brake, and it is only good for quick deceleration, but basically a fire hazard if you want to rely on that for tool changes. I have my VFD send out the signal to my air brake of when to engage. It has a relay programmed to change state when the VFD reaches 0 RPM.