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Setup Mach3 to stop all servos if the spindle stop

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Spindle stopped during code running
« on: May 11, 2015, 12:25:04 PM »
Hi Guys,
I just had a bad experience and really don't know how to handle it:
- The spindle motor stopped while running the code !!!
After resetting the machine the spindle was working ok, like nothing happened, so I assume that the controller has some sort of current overload protection that stops the spindle if overloaded.
I have a small 3040T cnc router with Mach3.
How can I set Mach3 to stop all activity (freeze servos and pause code running) if the spindle stops ?
Thanks for reading this guys and for the ones who will answer....thanks a lot.  
The more detailed answer you time permits...the better :)

Offline Hood

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Re: Spindle stopped during code running
« Reply #1 on: May 12, 2015, 02:40:57 AM »
Does your spindle controller have a fault output?
Do you have feedback to Mach for the spindle speed, in other words do you have an Index pulse set up?
Hood
Re: Spindle stopped during code running
« Reply #2 on: May 12, 2015, 03:35:36 PM »
Hood,
Thanks for the fast reply.
Well, this machine is a simple 3040T with a basic controller that has a spindle variable speed knob and an on/off switch for it.
I don't think that it has an index pulse setup. I cannot control the spindle from Mach (on/off or speed). From the cnc machine to the controller I have a parallel port cable, not separate cables for the servos and spindle.
Is there any way I can test or check if it is possible to control the spindle through Mach ?
If it is indeed "blind", is there anything I can do to prevent the machine running the code when the spindle faults for any reason ?
I asked the seller and he said that the spindle doesn't have any current overload protection but only short circuit protection. He suggested that the variable resistor (for the speed variation) might be faulty.
Thanks again for the time spent to read and assist in any way.
Cheers.

Offline Hood

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Re: Spindle stopped during code running
« Reply #3 on: May 12, 2015, 04:23:03 PM »
Afraid not, if there is no feedback to Mach at all, whether that be Index or fault signal, then there is no way for Mach to know if it is running or not.
Hood
Re: Spindle stopped during code running
« Reply #4 on: May 12, 2015, 05:36:29 PM »
You can alway hardwire in a safety relay. Something as simple as an ice cube relay with the same coil voltage as the spindle motor. Parallel the relay with the spindle motor and add to the estop loop. Anytime the spindle is off Mach would be in estop. This would also prevent you from running a code without the spindle on. Not ideal but works.  Ideally you should have a full safety system.
Don
Re: Spindle stopped during code running
« Reply #5 on: May 12, 2015, 06:37:45 PM »
Hi Don,
  This initially crossed my mind as well, but then thought .... anytime you intentionally stopped the spindle, you would go into reset. Loosing all reference, and would not be able to jog, or any other set-up without the spindle running.
I guess if all motion was stopped when stopping the spindle, and the drives didn't go off line there would be no pos. lost during a tool change. But, all reference would be lost.

Also , a question :
If the motor is a DC 90 or 180V , is there a relay coil that would work with the widely varying voltages ?
Thanks,
Russ
Re: Spindle stopped during code running
« Reply #6 on: May 13, 2015, 01:41:19 AM »
Good thought. Just put a hand off auto switch inline with it. Hand allows non spindle use. Auto estops the system?  You can get a relay is most voltages. How about adding a hawkeye (current sensor) on a spindle lead then program it to look for the input as a run confirmation? Someone else here would need to give the programming info. I'm not a programmer, just a dumb electrician.
Don
Re: Spindle stopped during code running
« Reply #7 on: May 13, 2015, 07:58:09 AM »
Hi,
I assume your spindle is DC motor? If so a Hall effect current sensor would be a fairly easy way to sense
spindle load or stall condition.
Most Hall effect sensors require +15-15V supply of 10mA or so and an op amp comparator and a couple of zeners for threshold
detection....
I could probably help with a circuit diagram if you want.

Craig
My wife left with my best friend...
     and I miss him!
Re: Spindle stopped during code running
« Reply #8 on: May 13, 2015, 08:04:47 AM »
I'd say the open loop "Stepper rule" applies here.
Don't attempt to run the spindle outside of its capabilities, repair anything that is inoperative, go to a larger motor/drive combo if necessary.

The sky's the limit for protection. Belt slippage, temp, torque load, ............
Just fix it.  :)
Russ